Nutrition: The Complete Guide
Second Edition
International Sports Sciences Association CERTIFICATION COURSES
Second Edition
Nutrition: The Complete Guide
800.892.4772 • ISSAonline.edu
1015 Mark Avenue • Carpinteria, CA 93013
1.800.892.4772 • 1.805.745.8111 (international) • 1.805.745.8119 (fax)
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International Sports Sciences Association CERTIFICATION COURSES
International Sports Sciences Association
John Berardi, PhD, CSCS
Ryan Andrews, MS, MA, RD
Brian St. Pierre, MS, RD, CSCS
Krista Scott-Dixon, PhD
Helen Kollias, PhD, CSCS
Camille DePutter
John Berardi, PhD, CSCS
Ryan Andrews, MS, MA, RD
Brian St. Pierre, MS, RD, CSCS
Krista Scott-Dixon, PhD
Helen Kollias, PhD, CSCS
Camille DePutter
Nutrition
The Complete Guide
issaonline.edu
Nutrition: The Complete Guide (Edition 2)
Official course text for: International Sports Sciences Association’s Certified Nutrition Specialist program
10 9 8 7 6 5 4 3 2 1
Copyright © 2018 International Sports Sciences Association.
Published by the International Sports Sciences Association, Carpinteria, CA 93013.
All rights reserved. No part of this work may be reproduced or transmitted in any form or by any electronic, mechanical, or other means, now
known or hereafter invented, including xerography, photocopying, and recording, or in any information storage and retrieval system without the
written permission of the publisher.
Direct copyright, permissions, reproduction, and publishing inquiries to:
International Sports Sciences Association, 1015 Mark Avenue, Carpinteria, CA 93013
1.800.892.4772 • 1.805.745.8111 (international)
DISCLAIMER OF WARRANTY
This text is informational only. The data and information contained herein are based upon information from various published and
unpublished sources that represents training, health, and nutrition literature and practice summarized by the author and publisher.
The publisher of this text makes no warranties, expressed or implied, regarding the currency, completeness, or scientific accuracy of
this information, nor does it warrant the fitness of the information for any particular purpose. The information is not intended for use
in connection with the sale of any product. Any claims or presentations regarding any specific products or brand names are strictly the
responsibility of the product owners or manufacturers. This summary of information from unpublished sources, books, research journals,
and articles is not intended to replace the advice or attention of health care professionals. It is not intended to direct their behavior or
replace their independent professional judgment. If you have a problem or concern with your health, or before you embark on any health,
fitness, or sports training programs, seek clearance and guidance from a qualified health care professional.
About the Authors | iii
About the Authors
Dr. Berardi has been recognized as one of the top exercise nutrition experts in the
world. He earned a PhD in Exercise Physiology and Nutrient Biochemistry at the
University of Western Ontario, Canada. His work has been published in numerous
textbooks, peer-reviewed academic journals, and countless popular exercise and nutrition books and magazines.
As an elite nutrition coach and exercise physiologist, Dr. Berardi has worked with
over 50,000 clients in over 100 countries, including Olympic gold medalists, world
champion UFC fighters, and professional sports teams. He is also an advisor to Apple,
Equinox, Nike, and Titleist.
Dr. Berardi was recently selected as one of the 20 smartest coaches in the world and
one of the 100 most influential people in fitness.
With a PhD from York University in Toronto and 10 years of university teaching,
Krista Scott-Dixon has over 20 years of experience in research, adult education, curriculum design, and coaching and counseling. In addition, she has spent over 20 years
pursuing self-education in health and fitness.
Through writing, coaching, speaking, teaching, and curriculum development, Krista
has galvanized thousands of clients to transform their health and fitness for the better,
and is guiding a new generation of fitness professionals to a higher level of success and
satisfaction.
Krista is the author of several books, dozens of popular articles, and many academic
publications. She also inspires readers at her groundbreaking women’s weight training
website, Stumptuous.com.
Ryan Andrews is a world-leading educator in the fields of exercise science and
nutrition.
Ryan is a Registered Dietitian with two master’s degrees. He completed his education
in exercise and nutrition at the University of Northern Colorado, Kent State University, and Johns Hopkins Medicine.
A highly respected coach who has been a part of the Precision Nutrition team since
2007, Ryan’s body of work includes an impressive number of articles, presentations,
books, and certification manuals on the topics of eating, exercise and health.
A nationally ranked competitive bodybuilder from 1996-2001, and now a certified
yoga instructor, Ryan is also an active volunteer with non-profit organizations to help
promote a sustainable future.
International Sports Sciences Association
iv |
Brian St. Pierre is a renowned expert in performance nutrition.
Brian is a Registered Dietitian with a Masters in Food Science and Human Nutrition
from the University of Maine. He is also a certified strength and conditioning specialist, a certified sports nutritionist, and the author of five books including the High
Performance Handbook Nutrition Guide.
As Precision Nutrition’s Director of Performance Nutrition, Brian contributes to
ground-breaking research, education and curriculum development at PN, where he is
also an esteemed coach.
Brian shares his expertise on a global scale by presenting at conferences around the
world, serving as a nutrition consultant for pro sports teams such as the San Antonio
Spurs, Brooklyn Nets, and Cleveland Browns, coaching professional and Olympic
athletes, and writing for popular publications including Precision Nutrition.
Camille DePutter is an author, speaker, and communications consultant with a rich
portfolio of experience in marketing, public relations, and storytelling.
Camille received her HBA in English from the University of Toronto and trained at
the Humber School for Writers. An advisor to Precision Nutrition, Camille lends her
communication expertise to Precision Nutrition publications, course materials and
marketing content.
As a consultant, Camille has helped dozens of top brands and business leaders refine
their messaging and improve their customer relationships. Her work has been published extensively in popular websites, magazines and newspapers.
Camille writes for the Precision Nutrition Encyclopedia of Food and is a frequent contributor to the Precision Nutrition blog. She is also the author of the workbook Share
Your Story, and self-publishes at camilledeputter.com.
Dr. Helen Kollias is a researcher and L1 Certification advisor at PN. She is also a
regular content contributor to the blog, where she uses her witty and articulate writing
style to make complex science accessible and entertaining.
Helen holds a PhD in Molecular Biology from York University, specializing in the area
of muscle development and regeneration, and a Master’s degree in Exercise Physiology
and Biochemistry from the University of Waterloo. She has also held research positions at some of the most prestigious institutions in the world, including John Hopkins University and Toronto’s Hospital for Sick Children.
Outside the lab, Helen has played and coached varsity soccer, and has been involved
in fitness and weight training for almost two decades. She also has two daughters with
whom she wants to share her joy of inquiry and experimentation, but above all, she
wants to teach them resilience, bravery, and grit.
Nutrition: The Complete Guide
How to Use This Text | v
How to Use This Text
When faced with new information, students usually wonder one thing:
“Will I ever need to know this in the real world?”
Whether it’s the cosine of an angle, Kepler’s laws of planetary motion, or the enzyme
responsible for forming citrate, students’ most common questions about what they’re
learning are:
“Will this be on the test?”
“Will I ever need to know this again in my life?”
We, the authors, know these questions well. We’ve asked them ourselves, most often
during our own high school, undergraduate, and graduate studies.
So now, as instructors living in the “real world”, we’d like to level with you: Probably
not.
Unless you become an engineer, you probably won’t need the cosine stuff. Unless you
go to work for NASA, you can probably forget Kepler. And the Krebs cycle? Well, you
won’t need that unless you teach biochemistry.
So why learn all this information?
Well, most of us don’t know what we want to be when we grow up. Work (and life) is
full of surprises.
You never know what career path you’ll follow, or what hobbies you’ll take up.
Be prepared for anything. Learn as much foundational knowledge as possible. Now
you have options.
But there’s another, more inspiring, reason for learning this stuff.
It’s actually kinda interesting. It helps explain your world. And makes you super-fun at
parties.
In fact, when you really dig into this knowledge, you might just change what you want
to do for a living because of it.
What this means
In this program, we’ll provide a lot of foundational knowledge.
We give you more details below.
This foundational knowledge — about stuff like cells, digestion, metabolism and
whatnot — can feel a little heavy at times. Especially if you’re new to this material. Or
you’re a practical, hands-on kind of person who would rather spend more time doing
than reading.
Hang in there.
International Sports Sciences Association
vi |
The payoff comes in the second section, where that foundational information gets
applied.
We’ll give you case studies. Strategies for working with real-world clients. Questionnaires and assessments to use with your clients. Psychological strategies for getting
clients excited about working with you. And all kinds of other fun things.
Even if you’ll never use the more theoretical material we teach you, you’ll still need
to know the science to apply it under “test conditions” — in other words, when you’re
sitting across from a client.
By the end of this course, we expect you to understand:
•
how the body works;
•
how to apply that knowledge to working with clients;
•
how to assess, monitor, and revise client programs;
•
how to communicate your knowledge effectively; and
•
how to get your clients on board with your nutrition plans and programs — hopefully feeling just as inspired as you about making progress and changing their nutrition
habits.
How the program is organized
This course is split up into two units.
Section 1: Nutrition science
In Section 1, we’ll go through all the nutrition information you’ll need to know, such
as:
•
•
How and why your cells work the way they do
How carbohydrates, fats, vitamins, minerals, and other nutrients interact with
your cells
•
How food becomes energy for maintenance functions, physical work, and repair
•
How your body balances out the food you eat with the work it does
•
How exercise affects nutritional needs and how nutrition affects exercise
Section 2: Nutritional practice
In Section 2, we’ll introduce you to how to coach, including:
Nutrition: The Complete Guide
•
What it means to be a good coach
•
How to prepare for clients
•
How to interact with different clients
•
How to assess clients
•
How to know which approaches are best for which clients
•
How to meet clients where they are (not where you want them to be)
•
How to keep clients progressing from day one until they reach their goals
How to Use This Text | vii
Other learning tools
Throughout the textbook, look for things like:
Unit objectives
Each unit contains clear objectives at the beginning. This will tell you what to focus
on, and give you goals before you even start reading.
Unit summaries
At the end of each unit, we’ll summarize the most important points from that unit.
These will confirm that you’ve learned what really matters, and give you another handy
tool for review.
Key terms
The first time a key term appears in the text, it is highlighted and a definition provided
in the margin. Familiarize yourself with each key term.
Case studies
Most units end with relevant case studies. These give you “real-life” examples of applied nutrition.
Each story describes a client’s nutrition challenges, then provides practical solutions to
work through these challenges.
References
We’ll provide a comprehensive list of references used to create this course. If you’re
interested in learning more about nutrition and health, you can look up and read more
of this primary source literature.
How to focus your learning
Just like coaching or training, learning should be focused and systematic, with a clear
purpose.
Here are some ways to stay on track and on target with your Level 1 journey.
Learn what you need to learn
You know your own learning style. (And if you don’t, now’s a great time to discover it.)
Help yourself succeed by building a system that suits you.
Use as many ways of processing the material as possible: reading, writing, thinking
and reflecting, listening, watching, talking about the material, drawing maps and
flowcharts of ideas, etc.
We suggest…
International Sports Sciences Association
viii |
1.
Read the unit. (textbook)
2.
Watch the video. (online)
3.
Answer the workbook questions. (study guide)
4.
Take the quiz. (online)
Set up a weekly self-study schedule so you get into a routine. Consistency and structure will help you move forward steadily and confidently.
Focus on key concepts
As the scientists working on the 1999 Mars lander mission found out when their
precious spacecraft wandered off into oblivion because they mixed up imperial and
metric measurements, details are important.
But details usually aren’t the most important things in this program. You don’t have
to memorize entire units, nor usually recall minute details (such as the exact body
density equation by Jackson & Pollock).
As long as you learn the concepts and study as we recommend, you have a great
chance of doing well on the quizzes.
Plus, you’ll always have your text available for reference. If you get stumped during a
quiz or a client interaction, you can always look things up.
It’s more important to know how to think. How to learn. How to connect ideas.
And to understand why things are important (and how they relate to one another) than
to recall specific details. (Unless detail memorization is your thing. Then go for it.)
What to look forward to
If you show up consistently, ready to learn and grow, and if you engage with this material using all the learning methods that work best for you, then this course will make you
a better coach.
Seek to master both the basic science (Section 1) and the applied art of coaching
(Section 2).
If you do, you’ll finish this program as a highly trained professional with the knowledge to support your recommendations; the ability to communicate them effectively
and well; and a foolproof system for delivering outstanding, reproducible results.
Let’s get started.
Nutrition: The Complete Guide
Acknowledgements | ix
Acknowledgements
It’s really important to us that everyone who helped bring this major project to completion is recognized for their work. Because, as we all know, nothing worth doing can
be done alone.
To this end we’d like to thank Paul Bradbury, Rachael Bell, Phil Caravaggio, Al Cimino, Alwyn Cosgrove, Alison Dungey PhD, Georgie Fear MS RD, Carmelo Galati RGD,
Jonathan Goodman, Sean Greeley, Mariane Heroux PhD, Timothy Jones, Bedros
Keuilian, Helen Kollias PhD, Sarah Maughan MS, Bob Moesta, John Nadalin, Spencer
Nadolsky DO, Tom Nikkola BA, Eric Noreen PhD, Prasanna Paul, Alex Picot-Annand
MS, Pat Rigsby, Francisca Ruff, m.c. schraefel PhD, Chris Spiek, Bryan Walsh ND, and
Erin Weiss-Trainor.
International Sports Sciences Association
Contents
5
How metabolism changes , p138
How exercise affects metabolism, p139
Introduction — Nutrition: The big picture, p2
Muscle and metabolism, p140
What is food?, p3
Energy demands of muscle, p143
What is good nutrition?, p6
Oxygen consumption, p144
What’s the best diet?, p11
Anaerobic versus aerobic exercise, p146
The cycle of food, p15
How we adapt to exercise, p148
What is nutrition coaching?, p16
Summary, p154
What this program will cover, p20
Summary, p20
6
Cells, p23
Cell structure and function, p24
Summary, p195
7
Vitamins, p199
Nutrition and cellular interaction, p28
Minerals, p201
Parts of cells, p31
Getting vitamins and minerals right, p203
Body function, p39
Vitamin and mineral overview, p205
Cell types, p42
Phytonutrients and myconutrients, p226
Summary, p44
Through the GI Tract, p45
Controlling the digestive process, p65
Summary, p229
8
Body water imbalances, p235
Summary, p76
Body water regulation, p241
Energy Transformation and Metabolism,
p77
Hydration strategies, p245
Summary, p251
Energy intake, storage, and transfer, p78
4
Water and Fluid Balance, p230
The big picture, p233
How do we absorb our food?, p70
3
Micronutrients, p197
Micronutrients, p198
How the body is organized, p25
2
Macronutrients, p155
Macronutrients, p156
Section 1: Nutritional science, p22
1
Aerobic and Anaerobic Metabolism, p137
How are nutrients metabolized?, p87
Section 2: Nutritional practice, p252
Summary , p111
9
What It Means To Be a Good Coach, p253
Energy Balance in the Body, p112
Why talk about coaching?, p254
Energy value of food, p113
What’s your story?, p255
Estimating energy needs and energy intake,
p119
What do great coaches do?, p259
Energy balance and imbalance, p124
Mental skills, p264
Achieving energy balance… naturally, p133
Communication skills, p267
Summary, p136
Summary, p269
Understanding clients, p262
10 The ISSA Nutrition Coaching
Methodology , p270
The process of change, p271
The 6 steps of coaching, p272
The early stages of the change process,
p278
Assessment and triage, p279
Identifying and clarifying values, priorities,
and goals, p283
15 Special Scenarios, p431
Start with the basics, p432
Disordered eating, p433
Food addiction , p442
Alcohol , p446
Nutrition and immunity, p447
Injuries / inflammation, p452
Sex and gender , p454
Choosing a direction for coaching and
building an early action plan, p287
Ethnicity, heritage and genetics, p461
Working through normal client
ambivalence, p290
Food sensitivities, p469
How to communicate effectively, p295
How we fit into the food system, p473
Putting it into practice: What’s ahead, p296
Summary, p299
11 Nutritional Levels, p300
Working with nutritional levels, p301
Summary, p316
12 Working with Level 1 Clients, p317
Level 1: Where it all begins, p318
Level 1 clients and your coaching process,
p321
Level 1 limiting factors and coaching
strategies, p327
Troubleshooting Level 1, p353
Summary, p359
13 Working with Level 2 Clients, p360
Life stages and aging, p462
Plant-based eating, p471
Summary, p478
16 Business 101 for Fitness and Nutrition
Pros, p479
What’s next for your coaching practice?,
p480
Smart business strategies for nutrition
coaching, p481
How to attract clients: Frequently asked
questions about sales and marketing, p488
Making it work: Avoid common mistakes,
p491
Summary, p492
17 Continuing Ed for the Coach, p493
Keeping up to date, p494
Taking it further, p495
Level 2: An introduction, p361
Staying on top of research, p496
Level 2 strategies, p370
Developing your coaching practice, p497
Troubleshooting Level 2, p393
Summary, p499
Summary, p397
14 Working with Level 3 Clients, p398
Level 3: Special situation nutrition, p399
Level 3 strategies, p404
Troubleshooting Level 3, p424
Summary, p429
References, p500
Index, p522
INTRODUCTION
Nutrition: The Big Picture
Nutrition: The Big Picture | 3
Unit Outline
1.
Objectives
5.
The cycle of food
2.
What is food?
6.
What is nutrition coaching?
3.
What is good nutrition?
7.
What this program will cover
4.
What’s the best diet?
8.
Case Study
9.
Summary
Objectives
This unit will introduce you to the big picture of good
•
nutrition.
You’ll learn:
•
how we define and think about food
•
how we define and think about good nutrition
why good nutrition matters for personal health, as well
as community and global health
•
how to answer the often-asked question: “What’s the
best diet?”
•
some of the things to think about when you sit down
to eat a meal
What is food?
Seems like a dumb question with an obvious answer. Food is stuff we eat that
fuels our body. Right?
Well, that’s one way to think about it. Food contains energy. Or, more correctly, “chemical bonds that, when broken, are used to create ATP, the fuel for our
cells.” (More on that in a later unit.)
But food also includes micronutrients, phytochemicals, zoochemicals, fiber,
water, and perhaps even organic molecules that we haven’t yet discovered. All of
these substances play crucial roles in our body, even though they don’t necessarily “fuel” it directly.
Zoochemicals: Components
found in animal food sources
Organic: Obtained from living
things
Micronutrients: Vitamins and minerals
We need vitamins and minerals in our diet. Without them, our body breaks
down.
Vitamins: Organic compounds
required by an organism as a vital
nutrient in limited amounts
For example:
Minerals: Naturally occurring,
inorganic substances
Vitamin C (also known as ascorbic acid) is a powerful antioxidant that can help
control inflammation and cellular damage.
The mineral magnesium plays a role in more than 300 enzyme systems and helps
with protein synthesis, muscle and nerve function, blood sugar control, blood
Inflammation: The reaction
of a tissue to injury or infection,
characterized by heat, redness,
swelling, and pain
International Sports Sciences Association
4 | Introduction
pressure regulation, energy production, and transport of
other minerals.
when you fill your car’s tank with gas, you know more or
less how far you can drive.
The list could go on and on. You’ll learn more about
these and other nutrients in later chapters.
But if you’ve spent any time doing “calorie math”, you’ll
know that trying to calculate precise inputs and outputs
for a human body is frustrating.
While none of these nutrients provide “fuel”, we still
need them to live and thrive.
When you’re missing key vitamins and minerals, your
body doesn’t work properly. You feel rotten. And you get
sick. That’s true no matter how much fuel is in the tank.
Phyto- and zoochemicals
Phytochemicals (whose name comes from the ancient
Greek phuto, or plant) are nutrients that only occur in
plants. Phytochemicals are one of the main reasons that
eating fruits and vegetables is good for us.
For instance, phytochemicals have been shown to:
•
offer DNA protection against free radicals;
•
protect against cancer;
•
decrease the risk of heart disease; and
•
reduce overall mortality.
Zoochemicals (from the Greek zoion, or animal) are
nutrients found only in animal products, such as CLA (a
fatty acid), creatine, and carnosine.
Zoochemicals have been shown to:
•
reduce inflammation and blood clotting;
•
protect against heart disease;
•
suppress cancer cell development; and
•
inhibit complications from diabetes.
•
Maybe you ate more calories than you thought you
should… but got leaner.
•
Or you ate fewer calories than you thought you
should… and gained weight.
•
Or you started eating breakfast instead of skipping
it…or vice versa... and dropped a couple of inches off
your waistline.
According to the simplistic “food as fuel” view, none of
this should be possible. Yet it happens all the time.
Human bodies aren’t combustion
engines.
They’re complex, dynamic, organic, and infinitely sensitive systems.
For example: Research now shows that all food isn’t created equal, and what we eat isn’t necessarily what we absorb
or use. Dozens — maybe even hundreds — of factors
affect how we digest, process, and utilize the food we eat.
This means that the fuel, or calorie, value of food
outside the body isn’t necessarily the same as the value
inside the body.
Plus, our body has its own priorities.
Phyto- and zoochemicals don’t provide “fuel.” Which
means that the “food as fuel” story leaves them out too.
For instance, the body will extract nutrients to keep you
alive by any means necessary, often making tough compromises along the way. This would be sort of like your
car suddenly driving itself to the gas station and holding
up the cashier until it gets what it needs, or cannibalizing its own headlights for fuel.
Food is so much more than fuel.
What’s more…
Living organisms are not machines.
Your body isn’t even completely
“human.”
They’re incredibly complex, self-regulating, and dynamically responsive — almost magical — systems.
Machines have precise inputs and outputs. For instance,
Nutrition: The Complete Guide
The trillions of microbial critters living in and on us do
much of our digestion and nutrient extraction. Analysis
Nutrition: The Big Picture | 5
of our bacterial environments shows that each of us has an individual gut flora
“microbiome”, like a fingerprint.
Changing our microbiome changes our digestion and absorption, and hence our
body composition and health.
Microbiome: The genetic
content of all the microorganisms
that inhabit the GI tract
We’re incredibly complicated, self-organizing, agenda-driven, only-sorta-human
systems. Frankly, the machines should be jealous. So, if the “food as fuel” idea
doesn’t give us the whole story, what is food?
Food is — in part — information.
When we eat, we’re delivering messages to our body.
•
Do this.
•
Don’t do this.
•
Release this hormone.
•
Don’t release that one.
•
Express this protein.
•
Don’t express that one.
Food (and the act of eating) sends instructions that kick off a chemical chain
letter. Each molecule of food contributes to a beautiful cascade of events, sending
all kinds of signals throughout our body.
Make hormones! Trigger immune cells! Switch genes on and off! Tell the work
crew to clean up and the builders to get on standby! Lights! Camera! Action!
It’s like the biggest, busiest movie set you can imagine. And somehow — unlike
many film sets — it runs almost perfectly.
Our body processes millions of calories and (let’s be scientific about this) zillions
of chemical compounds a year, with nearly 100% efficiency. (Just for comparison,
gas-powered engines, like our car, would be happy to hit 30% efficiency.)
Even cooler: Our thoughts, feelings, and environment can affect these processes. If we smell a tasty meal, have a positive or negative thought about food (or
anything else), are happy and relaxed or worried and rushing…it affects nutrient
processing.
Food is smart. And so is your body.
Thinking about food only as fuel reduces food to gasoline, your body to a dumb
machine, and you to a calorie accountant. You’re more than that.
Food and your body deserve a lot more recognition and honor.
The more we learn, research, and work with clients, the more we’re amazed at the
power of food.
International Sports Sciences Association
6 | Introduction
Food is packed with meaning,
information, and communication.
For a nutrition coach, knowing these stories is relevant.
Crucial. Powerful, life-shaping knowledge.
Every food decision we make sends a message to our
body.
Take a few minutes and consider these questions:
Every food choice is an opportunity to direct, shape, and
remake our health. Our body composition. Our performance. Our wellbeing.
Food tells a story.
Many of us in this field are physiologists and biochemists. Sure, we look at food through a science lens. But
that’s not our only perspective.
We know, too, that sharing food is a fundamental human act. Breaking bread (or whatever other food is on
the table) is part of our history. Our culture. Our legacy
as humans.
Food isn’t just a chemical story. It’s a story about
people.
How we eat, where we eat, and what we eat (or don’t)
tells a story. Food helps us communicate about who we
are, what we think about, and what’s important to us.
For instance:
•
I’m sophisticated. I’m a “foodie.”
•
I’m a thoughtful consumer. I’m a regular at the farmers’ market.
•
I’m from Mexico / Italy / Nigeria / Laos / [insert region
/ origin / ethnicity] and proud.
•
I’m the social hub for my big family. Come on over
this Sunday for dinner!
•
I’m adventurous. I’ll eat anything once. Once, when I
was traveling, I ate…
•
I’m careful with my choices. I avoid processed food.
•
I’m low maintenance; my fridge is empty. Let’s grab
something on the go.
•
I’m a bon vivant. I love eating at fancy restaurants.
•
I’m a caregiver. I love you. So I cook for you.
And so on.
These stories are essential information about ourselves,
about our family and friends, and about our clients.
Nutrition: The Complete Guide
•
What is food?
•
What is food… for you?
•
For your clients?
Is it fuel? Is it information? Is it personal freedom? Is it
shame? Is it self-esteem? Is it comfort?
Then consider these questions:
•
What would you like food to be?
•
What do you imagine it could be?
We encourage you to think big. Get imaginative. Learn
a little more about physiology. Learn a little more about
humanity. Discover what makes food one of the greatest
stories ever told.
A story of the wonder of evolution and biology. A
collective grand epic of our humanity. A chemical story
written in molecules, not words. It’s a story that shapes
your daily life, your health, and your function.
Food is fuel? No. It’s so much more than that.
What is good nutrition?
If food is more complicated than just fuel, then good
nutrition is probably more complicated than “following
the rules.”
Take a minute to answer this question for yourself: What
is good nutrition?
We’ve given this question a lot of thought over the years.
As of today, here’s how we answer it:
Good nutrition controls energy
balance.
As we’ve seen, food is more than fuel… but it does give
us energy.
Without enough energy coming into the body, we just
don’t work right. Our body starts to shut down processes
that we don’t absolutely need to survive, such as reproduction, some aspects of metabolism, and brain function.
Nutrition: The Big Picture | 7
Too much energy coming into the body also causes problems. We can become
resistant to important hormones (such as insulin or leptin). Inflammation may
increase. Plaques can form on vessels and blood pressure can go up. We risk
getting many chronic diseases.
Good nutrition helps control energy balance. We don’t eat too much or too little.
We can stay healthy, fit and strong. We feel good, and our body shows it.
Chronic diseases: A long-acting
disease that does not quickly
resolve, e.g., cardiovascular
disease, cancers, chronic
respiratory diseases and diabetes
Good nutrition gives us nutrients.
Each food has a certain nutrient density, or nutrients per amount of food. Since
we want to eat the right amount of food for our needs, we want to make sure that
that food is loaded with nutrients.
Imagine several plates, each one full of one type of food:
•
a plate of kale
•
a plate of lentils
•
a plate of cookies
•
a plate of salmon
•
a plate of berries
•
a plate of saltine crackers
Now, per plate of food, ask:
•
How many calories are in each plate?
•
How many nutrients are in each plate?
In some cases, like the cookies, there are lots of calories but few nutrients. That’s
called low nutrient density.
On the other hand, with the kale, there are lots of nutrients but few calories.
That’s called high nutrient density.
We need nutrients to live, and to thrive. Nutrients help us be as healthy as possible, perform at our best, and live long, active and vibrant lives.
Good nutrition helps us balance energy intake and getting enough of these
valuable, essential nutrients.
Table I.1: High- versus low-nutrient-density foods
Higher nutrient density
Lower Nutrient Density
Bright or deeply colored vegetables
Potato chips
Bright or deeply colored fruits
Soda and fruit juices
Beans, meats, eggs
Hot dogs, deli meats
Whole grains
Refined grains/flours, pastries
International Sports Sciences Association
8 | Introduction
Good nutrition helps us look, feel,
and perform our best.
Good nutrition — and good nutrition coaching — helps
our clients do what is most important to them, without
other things getting out of balance.
Performance
An athletic client might be focused mostly on performance. You can also help them stay healthy and strong
as they train. Or to be the right weight (or body fat
percentage) for their sport.
Body Composition
An older client might want to simply live healthier and
better. You can also help them keep the bone and muscle
that will keep them active and mobile.
A client who dreams of looking good at the beach or at a
big event (such as a wedding) might want to lose weight.
You can also help them prevent chronic diseases.
Good nutrition is about helping people look better. Feel
better. Perform better. Live better. And just be better
overall.
As a nutrition coach, take a holistic approach. Help your
clients balance specific goals with general benefits —
perhaps even benefits they didn’t realize were possible.
Good nutrition is outcome-based.
Every nutrition choice you make will lead to an outcome. Those outcomes can be measured. And they’re a
great mirror of reality.
That’s why we love the question “How’s that working for
you?”
Whenever someone tells us they eat really “healthy” —
which is just a concept in their head — the best follow-up is “Great! How’s that working for you?”
We use this question because it tests perception
against reality. If someone thinks they’re eating really
“healthy”, but they just don’t have the body, health,
or performance that could be expected, maybe that
person’s idea of “healthy” doesn’t match reality. Maybe
they’re not making outcome-based decisions.
Indeed, lots of people in North America think they have
a really healthy and balanced diet.
Yet, for example:
Nutrition: The Complete Guide
Health
Figure I.1 Good nutrition resides in the intersection between
health, performance, and body composition.
•
A study of Canadians found that over 60% of the calories they eat come from highly processed foods.
•
In the US, just over 11% of calories come from fast
food.
•
That “5 servings a day of fruit and vegetables” habit?
Data show that only 30% of people in the UK are doing it… and only 8% of Australians. (And often, those
vegetable servings are potatoes.)
•
Over 90% of clients report eating at least one meal in
a cafeteria or restaurant a day. While some people are
undoubtedly making healthy, less-processed choices
when they eat out, many folks are probably not.
That’s why good nutrition includes using outcomes (data
and reality) to inform future decisions.
Good nutrition is sustainable for
both us and the planet.
Can we keep eating and producing food the way we are
now? For how long?
Research suggests that we waste between 30 and 50% of
all food produced.
Nutrition: The Big Picture | 9
Food often travels thousands of miles between the farm and our dinner plate.
While global food production has gone up, hunger and malnutrition are still big
problems worldwide. And more crops than ever before are being grown to feed
livestock (not people).
With a planet that isn’t growing and a population that is, our food decisions need
to be more sustainable and environmentally considerate than ever before.
Luckily, what helps the planet usually helps our body and health as well. That’s why
good nutrition is about finding a diet that is sustainable for us and the planet.
Good nutrition is about removing limiting factors.
If you can help your clients identify their limiting factors — the things that stand
between them and reaching their goals — you’ll become a great nutrition coach.
While you’re building up your expertise, here’s a quick list of possible limiting
factors to look for. (We’ll share more examples later on.)
Genetics and epigenetics
Genetics (the blueprints of our body) and epigenetics (factors that control how
our genes are expressed) can affect how your clients respond to nutrition.
For example:
•
Few clients will have the genetic makeup to reach the upper limits of human
Epigenetics: The study of
changes in organisms caused by
modification of gene expression
rather than alteration of the
genetic code itself
performance.
•
Some clients will have genetic factors that can make losing weight, gaining
muscle, completely avoiding chronic diseases, or other physical outcomes
easier or harder.
•
Some clients will be genetically more or less able to metabolize certain foods
or chemicals, such as caffeine or particular amino acids.
Genes are not destiny. Epigenetic factors — such as nutrition, stress, or a healthy
environment — can strongly affect genetic expression. So you might carry several of the known gene variants for obesity… but you can also choose what to eat
for dinner, or put on running shoes and get outside.
Almost everyone can make daily choices that will keep them as healthy, fit, and
vibrant as possible, for their individual body.
Exercise
Amino acids: The building
blocks of protein. Organic
compounds containing both
COOH and NH2
Gene variants: Diversity in gene
sequence within a population
or among populations that are
most commonly due to single
nucleotide polymorphisms (SNPs)
or copy number variants (CNVs)
Activity changes how our body uses nutrients. Active and fit people can eat
more, use nutrients more efficiently and effectively, and keep their metabolisms
healthier than sedentary and unfit people.
So exercise (or lack thereof) can be an important limiting factor.
International Sports Sciences Association
10 | Introduction
At the same time, exercise alone isn’t enough to keep your clients healthy or lean.
(Which is one reason that your work as a nutrition coach is so important.)
Physiology
If you’ve ever had a serious metabolic or hormonal problem, or an imbalance of
neurotransmitters, you’ll know: Physiology is powerful.
Work with, rather than against, your clients’ unique physiological makeup, and
help them understand what’s realistic. (But stay hopeful.)
Take an integrated approach: Collaborate with your clients’ health care providers, if needed, to work together as a team.
Mindset
Every action starts with a thought. Thoughts become things.
Negative, sabotaging or inaccurate thoughts, self-talk and beliefs can hold your
clients back. Not only do negative mental dynamics affect clients’ behavior, they
also have physiological effects: Our brain and body treat these like any other
stressor, and respond accordingly.
Luckily, as a nutrition coach you can help replace negative mindsets with things
like positive self-talk or better information.
Notice how your clients think, and the stories they tell themselves. Consider how
you can also improve those thoughts and beliefs as part of your nutrition coaching. (We’ll look more at this in Section 2.)
Also consider how you can help your clients move from knowing information to
taking action.
A winning mindset plus a great nutrition action plan… that’s a recipe for success.
Environment
What’s around your clients?
Who is on their team? (Besides you.) How are their relationships at work, home,
school, or elsewhere?
What’s their schedule like?
What’s their physical environment like? Are healthy choices close and
convenient?
Most of our daily decisions are unconscious. We don’t think about them. We
just make them. So our environment strongly shapes what we do, eat, and think
about.
Even if your clients really want to make better choices, they’ll probably also need
to adjust their environment to do so.
Nutrition: The Complete Guide
Nutrition: The Big Picture | 11
Good nutrition looks for strengths and wins.
Good nutrition isn’t about “following the rules” or “being strict.” It’s about enabling happier, healthier, fuller lives.
As a nutrition coach, you’re looking for limiting factors, but also for your clients’
advantages, strengths, and opportunities for success.
How can you take what’s already working, and improve on it?
Now, of course, if you’re looking for strengths and wins, you’ll probably wonder...
What’s the best diet?
As a fitness professional, one question you will often get asked is which “nutrition camp” you fall into. Are you into Paleo? What about vegan? Intermittent
fasting? Detoxing? Or any number of other “flavors of the month” (so to speak)?
And clients will want to know:
“What’s the best diet?”
Paleo: A diet built upon foods
presumed to have been eaten by
early humans
intermittent fasting: A diet
that cycles between periods of
eating and not eating
The secret:
There isn’t one.
Here’s why.
Clients are diverse.
Here are just a few ways that your clients can differ:
•
Body type: Some clients are tall and thin; others short and stocky. Or everything in between.
•
Fitness level and body composition: Some clients are active, strong, lean,
and dense. Some clients have been sedentary for the last 50 years and may be
frail, without a lot of muscle.
•
Dietary preferences and exclusions: Whether kosher, halal or Jainist;
plant-based or carnivore; scavenger or “picky eater”; iron stomach or “allergic
to everything”, clients have a vast range of food preferences and many reasons
for them.
•
Budget: Your client might be a broke student, a middle-class family trying to
make ends meet, or a highly paid executive — perhaps even a pro athlete.
•
Organic / conventional: Some clients live on boxed and packaged foods.
Some clients try to read labels, sometimes. Some clients may choose only kale
that has been lovingly grown by a sect of Californian monks who hand-pluck
the bugs off.
International Sports Sciences Association
12 | Introduction
•
Nutrition knowledge and diet history: Some
clients will be devout followers of a certain dietary
practice, or a history of trying different diets. Others
have very little nutrition knowledge at all.
•
Time: Some clients have an open schedule, ready for
any kind of health and fitness project. Others have
a crowded daily schedule and countless conflicting
priorities.
•
Ethnic background and heritage: Our coaches
practice all over the world. Our clients live, and come
from, all over the world. A meal or cuisine that suits
an Anglo family may not suit their Hispanic, Somali,
or Punjabi neighbors. A client from a northern European ethnic group may digest dairy easily, while the
client of Japanese heritage next to them may not.
•
Age: As we age, our metabolisms change, our food
tolerances and appetites change, and our digestive
•
Good coaches stay skeptical, think critically, and take a
broad perspective.
Indeed, here’s one crucial piece of evidence:
The healthiest people in the world
don’t have a single nutrition
philosophy.
Physiologically, the human body can do well under all
kinds of different nutritional conditions.
We can see this clearly if we look at the traditional diets
of indigenous groups and ethnic groups throughout the
world.
•
ucts, with few vegetables.
•
Conversely, Kitavans in the South Pacific, the Hadza
of East Africa, and many groups in the Amazon basin
As a nutrition coach, your job is to help your clients — as
unique people — get to their goals. To do what matters
to them, in the way that’s best for them.
The best coaches don’t have a single
nutrition philosophy.
For example, the Arctic Inuit and African Masai eat
traditional diets that are high in fat and animal prod-
abilities change.
You get the picture.
“real-life” testing and client experience.
(such as the Tsimane of Bolivia) eat traditional diets
that are low in fat but high in vegetables and starchy
carbohydrates.
•
The !Kung of Africa eat traditional diets that are made
up of mostly nuts and seeds.
You might have the approach you like, or one that
worked for you. Great. That’s a solid start.
This is also true if we look at the world’s Blue Zones,
areas where people live exceptionally long and healthy
lives.
But good coaches take a flexible approach. They borrow
the best ideas from everywhere and everyone, and are
always looking for new insights or tools. They don’t get
stuck in dogma.
You probably wouldn’t mistake Okinawan cuisine for
the Mediterranean cuisine of Sardinia, Italy or Ikaria,
Greece. Or the Central American cuisine of Costa Rica’s
Nicoya peninsula.
The best coaches use data and
evidence to make decisions.
These cuisines and dietary patterns differ.
Throughout this course, we’ll encourage you to wear
your scientist hat and gather data for outcome-based
decision making.
Good coaches look at the evidence. This can include:
•
peer-reviewed clinical and scientific research;
•
understanding the basis of how and why things work
(or don’t); and
Nutrition: The Complete Guide
Yet people eating these ancestral or traditional diets have
much fewer of the chronic “diseases of affluence” (such
as cardiovascular disease, stroke, diabetes, obesity, etc.)
considered normal in industrialized areas.
The human body adapts amazingly
well to many different ways
of eating.
You can be healthy and fit whether you eat mostly meat
Nutrition: The Big Picture | 13
or mostly veggies, mostly fat or mostly carbohydrates, many times a day or just a
few times, and so on.
Carbohydrates: A group of
compounds including sugars,
starch, and cellulose
Which means that, as a nutrition coach, you shouldn’t really belong to any specific nutrition camp at all.
When you work with actual human beings, you must be a nutrition agnostic:
•
Explore and try anything and everything that could work.
•
Be willing to test new methods, even if they fly in the face of current beliefs or
practices.
•
Be humble and open-minded enough to let yourself be wrong, even if you
really like being right. (Which we do.)
Don’t focus on the food itself. Or on making sure everyone follows your “nutrition rules.”
Focus instead on your clients. What do they need to be their best?
Good nutrition is more similar than different.
You might be wondering: How can such varied diets all keep people fit and
healthy? Well, despite their disparities, most effective nutrition programs are
more alike than different.
1. Good nutrition asks people to care about their food
and eating.
Research shows that your actual choices are probably less important than simply
paying better attention to what you eat.
When you really care about what you eat, and make mindful, deliberate choices,
you almost inevitably eat better.
2. Good nutrition focuses on food quality.
Almost no decent diet plan asks you to eat more processed, nutrient-depleted
pseudo-food.
Instead, pretty much every camp recommends eating whole, minimally processed, nutrient-rich foods — foods with which our body has a longstanding
relationship.
Regardless of the macronutrient breakdowns or specific choices, just eating better quality food will improve most people’s health significantly.
3. Good nutrition helps eliminate nutrient deficiencies.
When we care about what we eat, choose foods mindfully, and try to get the
best-quality foods we can afford, we usually get lots of valuable nutrients along
for the ride.
Often, when people start a certain diet program, they just start eating better
International Sports Sciences Association
14 | Introduction
overall. They get more nutrients. They may get more variety. Or fresher foods. Or
less-processed foods. Or foods they chose mindfully.
Because of these factors, they feel better. And that’s one reason they start making
wild claims about the rejuvenating power of their new diet.
They didn’t do anything special, really. They often just started getting what their
bodies needed.
4. Good nutrition helps control appetite and food intake.
Hyper-palatable: Foods that
are exceptionally pleasing to the
sense of taste.
For most people, “it’s hard to eat just one” of the hyper-palatable deliciousness
bombs of processed foods. We often keep eating and eating them, but don’t feel
satisfied.
We may also eat them on the go, when we’re rushed and busy. So not only are we
eating foods that encourage us to eat more of them, we’re not even really paying
attention to the experience at all.
Conversely, when we’re more aware of what we’re eating; choose a variety of
more satisfying, higher-quality foods; and eliminate nutrient deficiencies, we
almost always end up eating less food overall.
We feel more satisfied — both physiologically and psychologically. We lose fat,
gain muscle, and perform better.
Notice that you don’t need calorie counting here. Focusing on food awareness
and food quality is usually enough for people to tune into their own hunger and
appetite. That means calorie control without the annoying calorie math.
It also means that your clients can stick with this, since almost nobody can count
calories (or wants to) forever.
5. Good nutrition promotes regular exercise.
When people start paying attention to their eating, they usually start thinking
about physical activity too. Or vice versa: If you take up an activity you love,
eventually you start wondering if your nutrition could help you do that activity
better.
Good nutrition fits with regular activity like a key into a lock.
And most nutrition programs suggest that people exercise along with eating well.
What this means for you as a nutrition coach
Stay open-minded and flexible. Question everything.
Learn more about global nutrition and eating habits. Broaden your focus.
Expand your world. (If possible, travel and actually experience different foods,
cuisines, and food philosophies.)
Test your theories and programs. See how they work on actual clients with real
lives and real bodies in the real world. Look for evidence. Gather data and measure outcomes.
Nutrition: The Complete Guide
Nutrition: The Big Picture | 15
Remember to ask our favorite question: “How’s that
working for you?”
And where possible, look for underlying themes that
make all good nutrition programs “work.”
One key feature about successful diet plans — especially in the Blue Zones — is that good nutrition connects
people to the food itself.
So now that you’ve thought about what food is, and what
good nutrition involves, let’s think about where food
comes from. Or where it goes.
The cycle of food
Check your fridge and pull out a fruit or vegetable.
•
Where was it grown?
•
How was it grown?
•
Who picked it for you?
•
How did it get to you?
•
What steps did it take?
•
How far did it have to travel?
•
What factors ensure you can get more of that fruit or
vegetable?
•
Do you think that people could still be eating that
fruit or vegetable in 100 years? What about 500?
Why?
In the world of nutrition for health, performance, and
body transformation, we don’t talk much about where
food comes from. Or where it ends up if we discard it.
Sure, we might check a few labels for the word “organic.”
But beyond that… well, many folks think that chicken is
just “protein” that comes in rectangular plastic packages.
(Wait… a chicken is a bird? That has feet, and feathers,
and stuff?)
Food as information about the world
Just as food is information for your body, food is also
information about ecosystems and the environment.
Food is information about how things get produced,
processed and sold all over the world.
Someone had to grow that fruit or vegetable from your
fridge. Other people picked it, and packed it, and transported it, and sold it.
Obviously, a full discussion of the social, political, economic, and environmental issues involved in agriculture
is beyond the scope of this text. We’ll touch on it briefly,
to help you understand a few more parts of the bigger
picture of food. If you’d like to learn more about these
issues, check out the agriculture resources in Unit 17.
Sustainability
Something sustainable is something that you can do
for a long time. That could be a well-planned nutrition
program, of course. Or in this case, a way of growing
and producing food.
Sustainable agriculture is agriculture that we can do for
a long time. It involves things like:
•
preserving and replenishing soil with nutrients;
•
preserving and replenishing water reserves, especially clean fresh water;
•
growing a wide range of diverse crops that are properly adapted for their surroundings;
•
making the best use of valuable farmland;
•
making animal welfare a priority;
•
understanding the interaction of living organisms as
a complex ecosystem rather than as a food factory;
•
making sure that people involved (such as growers or
pickers) are safe and fairly treated;
Figure I.2 The food life cycle
•
ensuring food safety and public health; and
•
minimizing waste and pollution.
International Sports Sciences Association
16 | Introduction
At its most basic level, sustainable agriculture is about
ensuring that we can produce safe, high-quality food for
everyone, for a long time to come.
Sustainability in agriculture isn’t just a nice thing to
have. It’s what will ensure we can keep eating the things
we want and need to eat.
We’ll talk more about sustainability and organic versus
conventional foods in a later unit.
Food as a set of choices
We’ve suggested that food is information, and a way of
telling a story.
Here’s another thing to think about: Food and eating is a
set of choices.
As a nutrition coach, one of your jobs is to make your
clients more aware of what they’re doing. Indeed, awareness itself can often change people’s behavior. (We’ll talk
about this more in Section 2.)
As we’ve stressed, nutrition coaching isn’t about getting
people to follow “the rules.” It’s about helping them
make more conscious choices. Choices that align with
their values, priorities, and goals.
We (and our clients) think about lots of things before we
buy and eat a food, such as:
•
what’s convenient;
•
what it costs;
•
what’s healthy (or not);
•
what we’ve done before (and in that case, we don’t
really “think” about it);
•
what’s available;
•
what might taste good;
•
what might feel good, distract us, or change our
emotional state; and
•
what is better for the environment, or more
sustainable.
Each client has their own decision-making process and
priorities.
Your role as a nutrition coach is to help your clients
Nutrition: The Complete Guide
become more aware of these processes and priorities —
to help them see that choices are at the end of a pathway.
And, if needed, you can help them change those pathways to change their choices.
As you look to deepen your own practice and increase
your awareness, think about food within a larger web.
We’ll talk more about how to implement small, manageable habits later in the course.
For now, just get the general idea:
•
Think about the big picture of nutrition, food,
and eating. Notice how adding some context helps
expand your understanding of what nutrition, food,
and eating are all about.
•
Think about what might be most important
for both you and your clients. Notice how there
are lots of options for diverse clients. (Don’t worry,
we’ll help you sort things and focus later.)
•
Think about how you might work towards
those values and priorities as part of nutrition
coaching. We know it’s a long-term project. Just
start with today… and keep reading.
What is nutrition coaching?
We’ve started to give you some ideas about what nutrition coaching is.
Let’s look more closely now at what the role of nutrition
coach involves.
First, congratulations.
Being a nutrition coach is an
important job.
You’re often the first person a client sees when
they want to look, feel, and / or perform better.
They might not go to their doctor or another health care
provider. Instead, they might come to see you.
You’re part of your client’s social support system.
Many clients don’t have family or friends who are willing
Nutrition: The Big Picture | 17
to help and support them as they improve their exercise
and nutrition choices. In fact, sometimes those family and
friends can actively sabotage your client’s efforts.
In the beginning, you may be the only team member a
client has.
You have the power to change lives.
If food and eating is information and a story, we can offer
new information and revise that story.
You can help change your clients’ bodies. You can also
help change their mindset about who they are and what
they can do. You can help change their ability to make
choices and try new things — to fully experience the
world around them.
Keep learning. Stay up to date.
Your clients want reliable, current, practical information
they can understand and use.
This means that you should have a process of ongoing
learning, information gathering and filtering, and sharing that knowledge.
Collaborate.
Being a nutrition coach is a big and important job. But
you don’t work alone.
Good nutrition coaches build and maintain a professional network with other health care professionals such as:
•
doctors
By helping prevent chronic diseases or nutrition-related
disabilities, or helping them change their relationships
with food, you might even save their lives sometimes.
•
registered dietitians
•
nurses
•
physical therapists
What does a good
nutrition coach do?
•
naturopaths
Fundamentally, a nutrition coach is a guide for change.
We’ll talk about this more in Section 2.
Here are some things that all good nutrition coaches
should do.
Be client-centered.
This means you’re an advocate and ally of the client. You
want to help them do what matters most to them… not
what matters most to you.
You listen to them. Try to understand their needs. Try to
understand their lives.
You see them as unique individuals, and try to match
your nutrition programming to what’s best for them.
Think collaboration rather than competition. You’re all
working together on your client’s team.
We also suggest you build a professional network to support your own practice. Look for people such as:
•
business coaches
•
accountants
•
marketers
•
web designers
Have good boundaries. Know your scope
of practice.
You’re not a therapist, medical doctor, or general fixit
person. Good nutrition coaches understand clearly what
they can and can’t do.
Help clients take action.
We’ll look more at client assessment and scope of practice in Section 2, but here’s a general overview.
Knowledge and information are great, but they’re not
enough. Your clients need to do stuff.
What’s your scope of practice?
Good nutrition coaches create clear, goal-driven, evidence-based nutrition plans that clients can immediately
start putting into action.
You’re probably here because you’d like to be able to
talk about nutrition with your clients, and to help them
International Sports Sciences Association
18 | Introduction
improve their food and eating habits. But it’s not always
clear what you can and can’t talk about with clients.
Here are the guidelines.
You can talk about nutrition with your
clients… if you’re qualified to do so.
In most jurisdictions, certified personal trainers or other
licensed health care professionals who have fundamental
nutrition knowledge can answer questions or address
concerns that their clients may have about nutrition.
Notice we emphasize the “fundamental knowledge”
part. With specific training, such as that provided in this
course, you’ll have that fundamental knowledge and be
able to discuss nutrition with clients.
Know your options where you live.
Each state, province, and country has different rules for
dispensing nutrition advice.
We’ve given you some resources below, and on our website, for learning more.
Offer general nutrition advice, not
medical nutrition therapy.
(Unless you’re qualified to do so, of course.)
With this ISSA credential, you’re able to make general
nutrition suggestions in most jurisdictions. You can also
share nutrition education using materials from a public
or well-known entity such as the American Heart Association, the Centers for Disease Control and Prevention,
and the Academy of Nutrition and Dietetics. (And of
course, ISSA.)
But unless you’re licensed or otherwise certified to do
so, you can’t offer specific advice in the form of medical
nutrition therapy.
Nutrition: The Complete Guide
This means you can’t prescribe nutrition for specific
health conditions and illnesses, such as:
•
post-surgical nutrition
•
diabetic nutrition
•
cancer therapy nutrition
•
nutrition to treat liver disease or kidney stones
•
nutrition for clinical eating disorders such as anorexia
Of course, the general advice you give your clients will
probably improve their health and lower their disease risk.
You just can’t offer directed advice that could reasonably be considered part of medical therapy. You can’t
use words like “diagnose”, “treat”, “cure” or “prescribe.”
(And unlike a lot of kooks on the Internet, you can’t
claim to magically eliminate all human suffering with
your wondrous diet plans.)
It’s not always completely clear where the boundaries
are, so when in doubt:
Collaborate with your professional
network of other health care providers.
It’s important to establish relationships with other health
care professionals, such as registered dietitians, nurses,
physical therapists, chiropractors, and physicians. By
networking and creating a cross-referral system, you’ll
not only be able to expand your business network, you’ll
have experts to turn to when you don’t know the answers
to certain questions.
Learn the rules and regulations of your
area.
The Center for Nutrition Advocacy provides a
comprehensive guide to statue laws. Visit www.
nutritionadvocacy.org/laws-state to fully understand
your states statutes.
Nutrition: The Big Picture | 19
Case Study
Many clients come to us with “diet experience.”
Some have done lower-carbohydrate diets, like the Atkins Diet. Others have done low-fat diets, like the Ornish
Diet. And others have done more “balanced” plans, like
the Zone Diet.
One client followed all three plans at one point or another, along with exercise.
In each case, the process and results were the same:
•
He followed the diet.
•
He lost about the same amount of weight.
•
He gained it all back… and usually more.
•
He tried another diet.
No matter what diet he tried — despite how “different” these diets were from each other — the same stuff
happened.
How can this be?
Well, instead of focusing on what makes diet plans different, let’s look at what makes them similar.
The client got the same results with different diets
because all three plans forced him to follow a key rule of
good nutrition:
All three plans, together with his exercise plan, forced him
to control his energy balance.
To lose weight, we need a negative energy balance. In
other words, we need to take in less energy (in the form
of food) than we expend (in the form of metabolism and
activity).
If someone loses weight, they’ve somehow managed to
get into negative energy balance.
carbohydrates. Or reducing fat. Or a specific macronutrient ratio.
All three plans create a negative energy balance in three
ways:
1. When clients follow a “weight loss plan”, they usually eat less. This decreases “energy in.”
2. Exercise increases “energy out.”
3. Both Atkins and Ornish ask dieters to restrict either
dietary carbohydrate or dietary fat. The Zone plan
asks dieters to eat a specific ratio of macronutrients — which usually means that people eat less of
whatever they were eating “too much” of. Is it any
wonder that by asking dieters to avoid eating something, they’ll end up eating less?
It wasn’t some magical macronutrient mix that made the
client lose weight. It was plain old energy deficit. (You’ll
learn more about energy balance in an upcoming unit.)
However, all three experiments ultimately failed.
Each time, the client rebounded. He gained more
weight after losing it. After giving up, he got off track,
stopped exercising, and started eating poorly again.
However, it wasn’t the food that caused this rebound.
It was many other lifestyle factors. The problem wasn’t
what he was eating necessarily… but how he was eating
and living.
Only when we started to address these key factors did
the client change his fundamental habits… and lose his
excess body fat for good.
In this program, you’ll learn that both the what (i.e., the
food itself) and the how (i.e., how we eat and live) are
crucial elements in change.
In this case, that’s what did the trick — not the lack of
International Sports Sciences Association
20 | Introduction
What this program
will cover
You should finish this course with both a better understanding of exercise nutrition and the tools used to deliver nutritional recommendations.
Here’s what we’ll do in the rest of this textbook and this
course.
Important note
•
Dispel common myths and fallacies associated with
nutrition.
•
Give you the foundational knowledge you’ll need
to make general nutritional recommendations to a
variety of clients.
•
Provide and explain nutrition theory and science.
•
Give you a clear process and walk you through the
steps of preparing for, assessing, evaluating, and
making recommendations for clients.
•
Give you a set of resources that you can use almost
immediately in your coaching practice (if you have
one already).
Completing this course will not qualify you as a
registered dietitian, licensed dietitian, or licensed
nutritionist. Check with the licensing bodies in your
area if you are hoping to get licensed.
Nor will this course allow you to provide medical
nutrition therapy.
Instead, this course will provide you with continuing
education in the field of nutrition.
It will enhance your credibility, your confidence, and
your skill set.
And it will help you overcome the biggest limiting factor
your clients face every day: poor nutrition.
Summary
Food is fuel, but it’s so much more than that. Food gives
us important substances such as micronutrients, phytoand zoochemicals. We need all of these nutrients to live
and thrive.
•
give us nutrients;
•
help us look, feel, and perform our best;
•
are outcome-based;
Living organisms are not machines. Human bodies
aren’t combustion engines. They’re more complex than
simple inputs and outputs.
•
are sustainable for both us and the planet;
•
are about removing limiting factors; and
•
look for strengths and wins.
Food is information and a story. Physiologically, socially,
and even environmentally, food and eating gives us
important information about things like:
•
chemical interactions in our body;
•
how we relate to ourselves and one another socially
and culturally;
•
how we make choices about what to eat (or not); and
•
how larger forces shape how food is produced and
consumed.
Good nutrition plans:
•
control energy balance;
Nutrition: The Complete Guide
What’s the best diet? Trick question! There isn’t one. The
best coaches don’t have a single nutrition philosophy,
and use data and evidence to make decisions.
Clients are diverse. The human body adapts amazingly
well to many different ways of eating. You can be healthy
and perform well on many diets.
Good nutrition is more similar than different. It:
•
asks people to care about their food and eating;
•
focuses on food quality;
•
helps eliminate nutrient deficiencies;
Nutrition: The Big Picture | 21
•
helps control appetite and food intake; and
•
promotes regular exercise.
Being a nutrition coach is an important job. You’re often
the first person a client sees when they want to look, feel,
and / or perform better. You’re part of your client’s social
support system. You have the power to change lives.
•
therapy.
•
be client-centered;
•
help clients take action;
•
keep learning; stay up to date;
•
collaborate; and
•
have good boundaries; know your scope of practice.
•
•
Know your options where you live.
•
help to dispel common myths and fallacies
•
give you the foundational knowledge you’ll need
to make general nutritional recommendations to a
variety of clients
•
provide and explain nutrition theory and science
•
give you a clear process for preparing, assessing,
evaluating, and making recommendations for clients
•
give you resources that you can use almost
immediately
You can talk about nutrition with your clients… if
you’re qualified to do so.
Learn the rules and regulations of your area.
This program will:
What’s your scope of practice?
•
Collaborate with your professional network of other
health care providers.
A good nutrition coach will:
•
Offer general nutrition advice, not medical nutrition
•
give you a better understanding of exercise nutrition and the tools used in delivering nutritional
recommendations
International Sports Sciences Association
SECTION ONE
NUTRITION SCIENCE
1
Cells, p23
2
Through the GI Tract, p45
3
Energy Transformation
and Metabolism, p77
4
Energy Balance in the Body, p112
5
Aerobic and Anaerobic Metabolism, p137
6
Macronutrients, p155
7
Micronutrients, p197
8
Water and Fluid Balance, p230
UNIT 1
Cells
24 | Unit 1
Unit Outline
1.
Objectives
2.
Cell structure and function
3.
How the body is organized
4.
Nutrition and cellular interaction
5.
Parts of cells
6.
Body function
7.
Cell types
8.
Summary
Objectives
You should be able to recognize:
In this unit, you’ll learn how your body’s cells:
•
get nutrients from the food that we eat, and
•
the main cell organelles;
•
use these nutrients for the raw materials and fuel to
•
what each organelle does; and
•
how each organelle interacts with organic molecules
keep us alive.
to do its most important jobs in the body.
At the end of this unit, you should have a working knowledge of how humans are organized, from the organismal
level all the way down to the atomic level.
You’ll start to build the foundation of physiological knowledge that you’ll need to make and apply nutrition plans.
Cell structure and function
The cell is the most basic structural and functional unit of all living things. All
living tissues are built from ells.
In terms of nutrition, our cells have two basic roles:
•
to get nutrients from the food that we eat, and
•
to use these nutrients for the raw materials and fuel to keep us alive.
How your body works depends on how each cell works.
Adult humans have trillions of cells. All work together to keep us alive.
To do these basic jobs, cells must:
metabolism: Sum of reactions
that take place to build up and
break down the body
Nutrition: The Complete Guide
•
grow, mature, and die;
•
exchange gases like oxygen and carbon dioxide (i.e., respiration);
•
absorb and digest nutrients;
•
circulate blood and other fluids;
•
get rid of waste; and
•
reproduce.
Together, these cellular tasks are known as metabolism.
Cells | 25
F. Organ
Tissues combine
to form organs.
Example: heart.
E. Tissue
Cells form tissue.
Example: cardiac
muscle tissue.
D. Cell
Organelles work together
to form cells. Example:
cardiomyocytes (cardiac
muscle cells).
C. Organelle
Molecules and atoms combine
to form organelles.
Example: nucleus.
B. Molecule
Atoms combine to form a molecule.
Example: deoxyribonucleic acid
(DNA).
A. Atom
Chemicals, such as carbon,
hydrogen and oxygen, are
the basic units of matter.
Example: carbon.
G. Organ System
Organs work together to form
organ systems.
Example: circulatory system.
H. Complex Organism
Organ systems sustain
complex organisms.
Example: you.
Figure 1.1. Organization of the human body. Atoms combine to form molecules. Molecules and atoms combine to form organelles.
Organelles work together to form cells. Similar types of cells form tissue, and tissues join to make up the various bodily organs. Groups of organs
that work closely together form organ systems, and it is these organ systems that ultimately sustain an organism.
We need proper nutrition for our cells to work properly. This means getting the right nutrients in the right
amounts.
And the body lives within even larger systems.
When we eat well, our cells function well. When we
don’t eat well, problems happen.
Our body lives within ecosystems — dynamic, interactive, interconnected networks of living things.
Healthy cells means healthy metabolism. Unhealthy cells
means unhealthy metabolism.
Some scientists even think that given how many bacteria
are on us and in us, humans aren’t even really “separate”
bodies at all!
How the body is organized
Organism
Cells — and by extension, the body — is organized into
systems, each system nested into another. See Figure 1.1.
Ecosystem
The organism is, well, you.
An organism is a definably self-contained living system.
International Sports Sciences Association
26 | Unit 1
For the purpose of this program, we can say that you as a human are a distinct
organism. (Bacterial buddies notwithstanding.)
homeostasis: The body’s ability
to maintain a stable and constant
internal condition
As an organism, the human body can reproduce, replace, and repair itself, all to
stay alive and to maintain homeostasis: the state of balanced function in the body.
Organ systems
Complex organisms, such as humans, are made up of organ systems.
•
Integumentary system: This system protects the body from external
damage. It includes your skin, hair, nails, sweat glands, and other external
structures.
•
Skeletal system: This system gives the body a rigid structure so that it can
move and hold itself up. It includes your bones, tendons, ligaments, and other
structures.
•
Muscular system: This system moves us, whether it’s to move you across the
room, to move your blood through blood vessels, or to move food through
your intestines. This system includes your skeletal muscles, cardiac muscles (in
your heart), and smooth muscles (part of arteries and veins, bladder, gastrointestinal tract, respiratory tract, uterus, and more).
•
Nervous system: This system sends electrochemical signals that trigger
thoughts, emotions, and movement as well as involuntary activity (such as
breathing). It includes your brain as well as a vast network of nerves and supporting structures.
•
Endocrine system: This is your cellular communication system. It includes
your hormonal organs and glands, including the hypothalamus, pineal gland,
pituitary gland, thyroid gland, liver, pancreas, kidney, adrenal glands, testes,
ovaries, and more.
enzyme: Substance that helps
catalyze chemical reactions
•
Circulatory system: This system transports hormones, enzymes, nutrients,
and other chemicals throughout the body. It includes your heart, blood, and
blood vessels.
•
Immune system: This system protects against pathogens, tumor cells, and
other foreign invaders. It includes your thymus, lymph nodes, spleen, tonsils,
and other similar organs.
•
Respiratory system: This system brings in oxygen and excretes carbon
dioxide. It includes your nasal cavity, trachea, lungs, and other airways and gas
exchange organs.
•
Digestive system: This system breaks down and absorbs nutrients from food
and drink. It includes your oral cavity, esophagus, stomach, intestines, and the
other organs associated with digestion including the liver, gallbladder, pancreas, and bile duct.
•
Urinary system: This system produces, stores, and eliminates urine. It includes your kidneys, ureters, bladder, urethra, and related organs and glands.
•
Reproductive system: This system controls reproduction as well as sexual
development. It includes your sex organs and glands.
Nutrition: The Complete Guide
Cells | 27
While these organ systems have distinct jobs, they also work closely together.
This is important for nutrition coaching.
For instance, if something is out of order in the gastrointestinal tract (say, with a
client who often gets an upset stomach), it’s probably out of order elsewhere (for
instance, in the endocrine system or nervous system). We’ll talk more about this
in later units.
Organs
Organ systems are made up of individual organs. Each organ has at least one specific job, and often several.
Tissues
Collectively, our tissues make up our organs.
•
Epithelial tissues make up our skin.
•
Connective tissues make up structures such as our joints and fascia.
•
Muscle tissues make up our skeletal muscles and heart, and are part of several other organ systems
Nervous tissues make up our brain, nerves, and associated structures.
Our tissues do many things, such as:
•
form protective barriers against outside invaders (epithelial tissues);
•
hold us together (connective tissues);
•
move the body around (skeletal muscle tissues); or
•
communicate between cells (nervous tissues).
Cells
Tissues are made up of large groups of cells.
Cells range in size from about 7 to 300 micrometers. To give you some perspective, the dot over this letter “i” is about 100 micrometers.
Cells show us how living matter is wonderfully unique in its diversity. For example, immune cells can engulf pathogens and destroy them, while muscle cells
have sliding filaments that cause muscle contraction and relaxation. (Fun factoid!
The axon of a motor neuron in the spinal cord can be up to 1 meter long.)
Organelles
Each cell is like a tiny city. Within each cell are organelles, collections of molecules / chemicals that have particular jobs, much like different utilities (such as
power production or waste disposal) within a city.
organelle: Component of the
cell that is responsible for a specific task
There are over 24 known organelles. We’ll talk about the most important ones —
such as the endoplasmic reticulum (ER), Golgi apparatus, and mitochondria — in
this textbook.
These organelles do their jobs in a semi-fluid matrix called the cytosol.
cytosol: Internal fluid portion of
the cell
International Sports Sciences Association
28 | Unit 1
Chemicals
Fundamentally, we are a soup of chemicals.
atom: Basic unit of a chemical
element
molecule: Group of atoms
bonded together
macromolecules: A large
molecule
Chemicals are built from structures of varying sizes, from atoms (smallest), to
molecules, to macromolecules (largest).
Macromolecules are made up of groupings of molecules. Molecules are made up
of tiny particles called atoms. And these atoms, which are invisible to the naked
eye, make up all material things of the universe.
So if you think about it, nutrition coaching is really about harnessing the fundamental particles of everything that exists.
As astronomer Carl Sagan famously said, “The cosmos is also within us. We’re
made of star stuff.”
Our body can only do what it does if our cells, and the organelles within them,
can do what they do: send and receive messages, create proteins, etc. Indeed,
nearly everything that happens in the body is based on making proteins, and
what those proteins do.
Think of the body as a manufacturing plant — that also manufactures itself. The
proteins we make not only break down and rebuild the plant itself, they break
down and rebuild the machines, the workers, the messengers, and lots of other
stuff.
We’ll get more into this idea as the unit progresses. For now, just remember that
every level of human organization depends on the health of important subunits
— our cells — and the proteins they make.
Nutrition and cellular interaction
macronutrient: Nutrient the
body requires in large amounts
(i.E., Protein, fat, carbohydrates)
micronutrient: Organic compound the body requires in very
small amounts (i.E., Vitamins and
minerals)
compounds: Consisting of two
or more substances
potential energy: Energy stored
within a physical system
In general, the macronutrients (proteins, carbohydrates, and fats), micronutrients (vitamins and minerals), phytochemicals, and zoochemicals we eat are broken down through the digestive process into smaller compounds such as amino
acids, glucose, fatty acids, etc.
These digested and absorbed compounds then travel through our bloodstream
to interact with our cells. Our cells use those compounds in many ways, such as:
1. To provide potential energy that’s later released by breaking the chemical
bonds between the macronutrients.
2. To provide raw materials that can then be incorporated into our body structures,
including tissues and organs.
co-factor: Non-protein compound that interacts with
another substance to facilitate a
transformation
3. To act as co-factors for chemical reactions in the body. All of the chemical
reactions that take place in the body require the help of particular proteins called
enzymes. These enzymes often use nutrients gathered from the food we eat to
do their job.
hormone: Compound created by
one cell that travels to and stimulates another cell
Nutrition: The Complete Guide
4. To stimulate the release of hormones, which act as chemical messengers,
directing overall body function with their unique messages.
Cells | 29
Cell nucleus contains chromosomes.
DNA provides cellular instruction
for making proteins.
Chromosomes contain DNA.
Figure 1.2. DNA inside the nucleus. Wrapped up in chromosomes, our DNA, or genetic code, dictates which proteins are
formed in the body. The nucleus of each cell contains this genetic code. Each person has a unique genetic code that influences how
we respond to ingested foods.
Because of these various and important roles that nutrients have, the food we eat
can fundamentally change how our body works. No wonder nutrition is so critical!
Nutritional individuality
In the previous unit, we looked at why there is no one “best diet.”
One reason is that not everyone responds the same way to the digestion and
absorption of particular foods — or to the uptake of particular nutrients into
the cell. Research suggests that although the basic mechanics are the same, there
are important and intriguing individual differences, which are likely due to our
unique genetic makeups.
Each cell in our body houses our genetic code, a series of nucleic acids called
DNA, in an organelle called the nucleus. This code, which is unique to each of
us, provides cellular instructions for making proteins we need for our structure
and function.
As we all have slightly different genetic profiles, the proteins we make may also
differ. These variations are responsible for our individual responses to the food
we eat. See Figure 1.2.
genetics: Specific, inherited DNA
of an organism, which influences
what they become, although
environment also plays a key role
in the expression of an organism’s
genetic code
DNA: Nucleic acids that contain
instructions for heredity
nucleus: Organelle where genetic material is housed
In general, these differences are quite small. All humans share over 99.9% of
International Sports Sciences Association
30 | Unit 1
gene: A particular sequence in
DNA or RNA that controls the
expression of a protein, and, by
extension, influences the characteristics of an organism
evolutionarily conserved:
Something that’s remained essentially unchanged throughout
evolution
the same genes. You may have even heard that humans and chimpanzees share
between 95% and 98% similarity in their DNA, which is also true.
In addition, many important genes have been evolutionarily conserved. This
means that those genes appeared very early in our evolutionary history, perhaps
even back in the days of single-celled bacteria.
For instance, much of what we know about the health effects of fasting comes
from research on a tiny, primitive flatworm known as Caenorhabditis elegans.
C. elegans has nearly 200 known genes that respond to dietary restriction. These
genes are involved in things like knowing when metabolism is disrupted; looking
for and repairing DNA damage; and hunting for cancer-type overgrowths. We
share 45 of those genes.
Thus, we are much more alike than we are different.
genetic polymorphism:
Variation in the form of one or a
sequence of genes
However, these small genetic differences, called genetic polymorphisms, explain
why some people respond slightly differently to various types of foods. These
differences may also explain why many research studies seem to have confusing
or conflicting conclusions.
Differences in nutrient processing
For example, we all have a gene in our liver for making a particular enzyme that
breaks down caffeine. However, due to these small genetic differences, some of us
have the enzyme that breaks down caffeine quickly. Others have the enzyme that
breaks down caffeine slowly.
•
In people with the fast enzyme, caffeine is processed and removed quickly,
while the antioxidants found in coffee can help protect against free radicals.
•
However, in people with the slow enzyme, the caffeine hangs around longer,
causing health problems.
So imagine a study that asks: “Is 1-3 cups of coffee a day healthy or unhealthy?”
The answer would be: “For whom?”
Differences caused by nutrients themselves
bioactive: Having a biological
effect
Not only are there individual differences in response to the same foods, different
foods have particular nutrients and other bioactive components that can actually
change the message expressed by our unique genes.
For example, isothiocyanates found in broccoli can switch on a gene in the liver
that detoxifies cancer-causing chemicals and other toxins.
upregulated: An increase of a
cellular component
Without the broccoli, this gene stays inactive. Our body looks for other detoxifiers. With the broccoli, this gene is upregulated and participates more actively in
the detoxification process.
Some of us have this gene, and some don’t. If we don’t have the gene, broccoli
can’t help us fight cancer in this particular way. (Of course, broccoli does other
good things.)
Another example is cooked tomatoes, which contain compounds (lycopenes)
Nutrition: The Complete Guide
Cells | 31
that switch off growth-promoting genes in the prostate. With cooked tomatoes in
the diet, prostate cancer risk decreases; without the tomatoes, risk increases.
Fish oil is yet another example. Fish oil (specifically DHA — a fatty acid found in
fish, other marine animals, and fish / algae oil supplements) might signal genes
in the brain to produce a chemical that preserves brain function with age. People
who consume more omega-3 fats tend to have better cognitive function as they
age, compared with those who consume less.
Thus, nutrition can strongly influence our gene expression. And our genes, in
turn, affect how we respond (or don’t) to a given nutrition plan. This genetic diversity and its relationship with nutrition is an emerging area of research called
nutrigenomics.
Needless to say, there is an important relationship between what we eat and how
our cells function. Throughout this course, this interaction will become clearer.
DHA: Docosahexaenoic acid, an
omega-3 fatty acid
nutrigenomics: Study of how
genes respond to nutritional
intake
By the end of this course, you should have a better grasp of how to optimize
health, body composition, and performance by controlling nutrient intake.
However, before we talk more about food, let’s discuss the cell in depth, and in
particular, the main cellular components and organelles.
Parts of cells
To better understand how the food we eat interacts with our body, it’s important
to learn about the structures, chemicals, and organelles within each of our cells.
In this unit, we’ll review the following organelles:
Plasma membrane
Golgi apparatus
Mitochondrion
Lysosome
Nucleus
Peroxisome
Endoplasmic reticulum
These organelles and approximately 17 others (there are about 24 or so in total)
give our cells their structure and function, which are in turn often shaped by our
nutrient intake.
Plasma membrane
Around the edge of each cell is a boundary, known as the plasma membrane,
which separates the cell from its neighbors and from the rest of our body. The
plasma membrane’s bilayer (double layer) acts like a protective wall, keeping
important chemicals in while keeping harmful chemicals out.
The plasma membrane is made up of lipids, proteins, cholesterols, and other
chemicals. It has an interesting nature: while it forms a structural boundary
between the cell and the rest of the body, this boundary is flexible and fluid-like.
Membranous organelles — specialized sacs and canals — can float around within the plasma membrane, rather like icebergs floating around in the ocean.
This fluid-like boundary is made up mostly of phospholipids, molecules with
phosphate “heads” and fatty acid “tails.” The phosphate “heads” of the lipid
molecules that form the bilayer are hydrophilic (water-loving) and therefore can
plasma membrane: Lipid bilayer that is permeable to certain
compounds that contains the cell
lipids: Any class of organic compounds that are fatty acids or their
derivatives
cholesterol: Synthesized in the
liver; precursor of bile acids and
steroid hormones
phospholipids: A type of lipid
with a hydrophilic phosphate
group “head” and hydrophobic
fatty acid “tail” that forms cell
membranes
hydrophilic: Strong affinity for
water
International Sports Sciences Association
32 | Unit 1
Extracellular space
Hydrophilic
region
Phospholipid
Hydrophobic
region
Hydrophilic
region
Intracellular space
Figure 1.3. Plasma membrane. The plasma membrane is composed of lipids, proteins, cholesterol and other chemicals. The lipid
bilayer has water-loving (hydrophilic) heads and water-fearing (hydrophobic) tails. Substances generally pass through the plasma
membrane via a transmembrane protein.
hydrophobic: Lack of affinity for
water
bond to water-based molecules. On the other hand, the fatty acid “tails” of the
lipid molecules that form the bilayer are hydrophobic (water-fearing) and bond
best with fat-based molecules.
This dual-purpose membrane creates a boundary that regulates what gets into
and out of cells. See Figure 1.3.
The cell needs to be choosy about what can enter and exit. Thus, most molecules
must enter the cell through one of several membrane proteins. These proteins are
like gates in a fence, allowing only particular molecules to pass through. We’ll
talk more about these cellular proteins later in this unit.
Because of this lipid structure, the types of fats we eat can change how fluid or
flexible the cell membrane can be.
Nutrition: The Complete Guide
•
Too much saturated fat may cause the membrane to be too rigid.
•
Too much polyunsaturated fat may cause the membrane to be too fluid.
Cells | 33
Because most people eat too many saturated and trans fats, we often need to
balance that with getting enough mono- and polyunsaturated fats. We’ll look
at this more later on. For now, just remember that fat balance affects how the cell
works in important ways.
Cytosol
saturated fat: A fat with no double bonds between the individual
carbon atoms of the fatty acid
chain
trans fat: Fat derived from the
partial hydrogenation of vegetable oils
The interior space of the cell is composed of a gel-like solution called cytosol.
Many organelles, enzymes, salts and other organic molecules, including stored
carbohydrates and fats, are suspended and maintained by the cytosol. The body
carries out many of its chemical reactions in this gel-like matrix, including most
of its enzymatic reactions. Cytosol, together with all the organelles, except the
nucleus, are called cytoplasm.
monounsaturated fat: A fat
with one double bond between
the carbons in the fatty acid chain
The cytosol is rich in stored carbohydrates that can be broken down quickly and
used to transfer energy. This process is controlled by cytosolic enzymes.
cytoplasm: The protoplasm
within a cell, excluding the
nucleus
polyunsaturated fat: A fat
with two or more double bonds
between the carbons in the fatty
acid chain
Exercise and other physical activity creates a demand for more energy. The cell
responds by making more of these enzymes along with storing more carbohydrate and fat for future use. The cell also gets better at breaking down these
carbohydrates for energy. This is especially true in skeletal muscle cells, since this
is where active people need most of their energy.
A key point here for nutrition coaching is that regular exercise and other activity
can powerfully affect cellular makeup, metabolism and function. Activity can fundamentally change how the body uses, processes, and stores nutrients. Active bodies will thus respond differently than inactive bodies to the same nutrition plan.
Mitochondria
Mitochondria (plural of mitochondrion) convert nutrients into energy.
Just like you can’t eat an egg until you crack open its shell (well, at least we don’t
recommend it), you can’t use the energy stored in carbohydrates, proteins, and
fats until you break their chemical bonds. Mitochondria convert the energy
released from this process into adenosine triphosphate (or ATP), the energy
currency of the cell.
mitochondria: Organelles that
supply the cells’ energy / ATP
(singular: mitochondrion)
adenosine triphosphate: ATP,
source of energy for physiological
reactions
Mitochondria produce most of the body’s energy — about 95% of it. The rest is
produced in other parts of the cell. If mitochondria don’t work well, we don’t
work well. (Or at all.)
Mitochondria make ATP in their inner mitochondrial membranes. The outer
membrane of the mitochondrion is porous, while the inner membrane is the
main barrier between it and the rest of the cell. The inner membrane contains
folds called cristae, which are studded with the enzymes and structures that help
make ATP.
mitochondrial membrane:
The double biomembrane surrounding the mitochondrion
Since the mitochondria generate power for the cell, more mitochondria means
more energy, and more active cells. Conversely, the more active we are, the more
mitochondria we likely have (and since your heart is beating all day, every day, it
also has plenty of mitochondria to keep pace). More mitochondria means more
total energy production for a muscle.
International Sports Sciences Association
34 | Unit 1
Nutrition in practice
Your skin color, body size, hair type, and risk of specific illnesses all depend on
how your genes interact with your environment.
For instance, your genes may suggest that you’ll grow to somewhere between
5’5” and 5’8.” But your actual height is an interaction between genes and environment. If you grow up malnourished, you won’t ever reach 5’8.”
What we eat early in life (and what our moms eat while they’re pregnant) can
affect our genes and regulate our traits — including the development of diseases, even decades later.
For example, data from the WWII Dutch Famine show that children of undernourished mothers had higher risk for cardiovascular disease, obesity, and breast
cancer later in life. (In fact, this “famine memory” can persist for generations,
“remembered” by descendants’ genes.)
Our genes can be influenced by all kinds of things, such as:
•
nutrient deficiencies or excesses (especially at crucial developmental
stages);
•
dietary components (e.g., omega-3 fats, phytoestrogens, cruciferous
vegetables, lycopene, folate, carotenoids, and so forth);
circadian: Any biological process
that recurs naturally on a daynight cycle
•
sunlight and vitamin D;
•
toxins (such as industrial chemicals, pesticides, heavy metals);
•
bacteria and viruses;
•
exercise and activity;
•
alcohol and other drugs;
•
stress, trauma, and mood;
•
circadian rhythms (such as sleep, shift work, light-dark cycles, and travel
across time zones); and
•
a host of other factors we probably don’t even know about yet.
If that sounds a little scary, consider it from the opposite perspective: While we
can’t control our genes themselves, we can affect their expression — whether
they’re likely to get “switched on” or off.
Our genetic expression is strongly shaped by our environment… over which we
do have some power. So, if we know more about our genetic variants, we might
be able to adjust our lifestyle or environment in order to prevent some illnesses
or become healthier.
Nutrition: The Complete Guide
Cells | 35
For example, certain gene variants can tell us:
•
how food is metabolized;
•
whether carcinogens in cooked meats will influence the development of
colon and prostate cancers; or
•
our inflammatory response and efficiency of DNA repair / replication.
If we know more about our own unique risk factors, we might be more likely to
make healthier choices — choices that could improve our genetic expression.
Genetic screening may show us the way to individualized nutrition and exercise
prescriptions. But we’re not quite there yet. Here’s what we know right now.
One size doesn’t fit all.
Genetic subgroups might respond differently to different foods and activity
types. In theory, genetic screening might help us customize food (and supplement) intake and exercise prescriptions for each person’s unique needs.
The details are kinda hazy.
In practice, it’s not as clear how genetic diversity might play out or how much it
even matters. After all, we also choose food and exercise based on other things
like taste, preference, convenience, price, and cultural norms.
Gene expression isn’t a destiny. It’s a set of possibilities.
What if your genes show you’re all slow-twitch endurance athlete but you think
fast-twitch sprint events are more fun? How closely should you stick to your
“blueprint”? How much can you affect your genetic expression through environment and habitual choices?
We don’t have all the answers yet.
Measuring nutrient-gene interactions takes time and effort. Genetic mapping is
complicated, sometimes expensive, and error-prone. And for any of this to matter, gene testing has to tell us what to actually do with that information. Genetic
testing is interesting. Provocative. Complex. And let’s be honest, kinda cool. But
for now, it raises more questions than it answers.
Stay tuned.
When genetic screening companies are able to more cost-effectively test the
entire genome (again, most only test a part of it) we should have a greater
understanding of gene sequencing and its use in nutrition. Most experts predict
that’ll happen within a few years, as the cost of sequencing the entire genome
drops from $10,000 to $500.
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Matrix
Cristae
Outer membrane
Inner membrane
Figure 1.4. Mitochondria. Inside the mitochondria is where energy converts to ATP. The number of mitochondria in a cell is directly
related to the activity of the cell.
Elite athletes usually have a high mitochondrial density.
This means they not only build more total mitochondria
with training, they also build more mitochondria per
unit of muscle mass. This gives them the ATP they need
for high-level performance. Once again, we can see how
regular movement and activity can change the fundamental structure and function of cells.
Having a lot of mitochondria is good, but we also want
them to be effective. In other words, we want mitochondrial quality as well as quantity. In order to understand
this, let’s look at a little bit of biochemistry.
When we make ATP for energy, our cells consume
oxygen, and produce reactive oxygen species (ROS) as a
byproduct. Just as with nutrient processing, not everyone does this at the same rate.
Different people may make ATP at different rates. They
may use different amounts of oxygen to do this; they may
need different amounts of food energy to do this; and they
may produce different amounts of ROS in the process.
Nutrition: The Complete Guide
In general, although ROS are a natural part of this reaction, we don’t want to make too many at once, or have
them hanging around too long. ROS can cause cellular
damage, including damaging our DNA.
Scientists used to think that the more oxygen we consumed, the more ROS we’d make. However, we now believe that mitochondrial efficiency changes this equation.
•
People with less-efficient mitochondria make more
ROS with every unit of ATP they produce.
•
People with more-efficient mitochondria make fewer
ROS for the same amount of ATP.
So if your mitochondria are efficient, you make lots of
energy with fewer damaging waste products. You feel
great, you perform well, and you live longer.
While there is a genetic component to mitochondrial
function, it’s strongly affected by how we live, what we
eat, and what we do.
See Figure 1.4 for more.
Cells | 37
Nutrition in practice
Nutrient deficiencies can affect our mitochondrial function. Statin drugs, depression, fibromyalgia, or Parkinson’s disease are all associated with low levels of
co-enzyme Q10 (CoQ10). We need this compound for energy production in the
mitochondria.
Another compound, an amino acid called L-carnitine, is also involved in energy
production in the mitochondria. L-carnitine is found mainly in animal foods.
While our body can make L-carnitine, clients who eat a mostly or entirely plantbased diet might find supplementation helpful.
Nucleus
The nucleus, usually found in the central part of the cell, is the largest organelle.
Most cells have only one nucleus, though muscle cells have more than one. The
nucleus is Mission Control, home of our DNA, also known as the genetic code.
Wrapped up in chromosomes, our DNA dictates which proteins are formed in
the body. This ultimately determines everything from how the body develops,
to how it repairs itself, to how it transports and / or metabolizes every chemical
introduced into circulation. In many ways, our DNA also determines how muscular we can get.
chromosomes: Located in
the nucleus, contain genetic
information
As we’ve discussed, there is an important link between our DNA, our food
intake, and our health. In fact, much of what we eat interacts directly with our
DNA or causes hormonal cascades that influence our DNA.
transcription: The synthesis of
RNA using a DNA template
These relationships begin in our nucleus: Chemicals can bond with our DNA to
begin making cellular proteins, processes called transcription and translation.
translation: Forming a protein
molecule based on the information contained in the mrna
ER and Golgi apparatus
endoplasmic reticulum:
Cytoplasmic membrane that
translates proteins
The endoplasmic reticulum, or ER, is a “circulatory” network found inside the
cytosol, near the nucleus.
When our DNA sends out a signal to make proteins, the ER and Golgi apparatus
receive this genetic message. They then make and transport the proteins.
There are two types of ER: smooth and rough.
Golgi apparatus: Cytoplasmic
organelle necessary for the modification and transport of proteins
ribosomes: A complex rich in
RNA and protein found in cells
Rough ER is lined with ribosomes, which give it a “rough” appearance. Ribosomes are the protein factories of the cell.
steroid hormones: Hormones
possessing steroid ring system,
including androgens, estrogens,
and adrenocortical hormones
Smooth ER doesn’t have ribosomes, so it doesn’t make proteins. Instead, it builds
lipids, steroid hormones, and carbohydrates to use in glycoproteins.
glycoproteins: Protein that
contains a carbohydrate group,
involved in membrane integrity
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Rough endoplasmic
reticulum (ER)
Nucleus
Transport vesicle
from ER
Cis (C) face:
receives transport
vesicles from ER
Golgi apparatus
Transport vesicle
from Golgi apparatus
Trans (T) face: produces
vesicles for cellular
use or for excretion
Figure 1.5. Endoplasmic reticulum and Golgi apparatus
protein synthesis:
Manufacturing of proteins from
amino acids; guided by DNA
Making proteins, or protein synthesis, takes place using ribonucleic acids
(RNA).
ribonucleic acids (RNA):
Various nucleic acids on a single
strand containing ribose and
uracil, necessary for the control of
cell activities
Once these proteins are synthesized in the ribosomes of the rough ER, they move
towards the Golgi apparatus. This organelle prepares the newly formed protein
molecules that will leave the cell.
cisterna: Flattened membrane
disc of Golgi apparatus (plural:
cisternae)
vesicles: Fluid filled pouch/
sac that can transport and store
compounds
The Golgi apparatus contains cisternae (tiny disc-like “holding tanks”, similar to
the word “cistern”) that are stacked on one another and small, circular vesicles.
These vesicles (small sacs) act like little chaperones, engulfing the protein molecules and transporting them to the cell membranes, where they’ll either be sent
elsewhere into the body, or incorporated into the membrane itself. See Figure 1.5.
Proteins are thus always being built up and broken down within our cells. This
takes energy and protein for raw materials. If we don’t eat enough, or don’t eat
enough protein, our cells can’t do their jobs of synthesizing and transporting
the proteins we need. Over time, this can lead to problems such as hormonal
imbalances, depressed immune function, or poor recovery from exercise (perhaps even injuries).
Lysosomes and peroxisomes
lysosome: Organelle containing
hydrolytic enzymes
microorganism: Organism of
microscopic size
peroxisome: Cytoplasmic organelle with enzymes that help with
the breakdown of fatty acids and
other macromolecules
Nutrition: The Complete Guide
Lysosomes are the “garbage disposal units” of our cells. They are vesicles, containing more than 50 different enzymes, which can break down cellular components and protect cells. If a large molecule, such as an old cellular structure
or a microorganism, enters the cell, the lysosome will engulf it then digest and
dispose of it. By keeping the cells clear of waste and debris, lysosomes help renew
and protect the cell.
Peroxisomes are similar to lysosomes: they are small membranous sacs
Cells | 39
containing enzymes (catalase and oxidase), which also detoxify harmful substances that enter cells. Found commonly in liver and kidney cells, peroxisomes
are also important in cholesterol synthesis, bile acid synthesis, ß-oxidation, and
prostaglandin metabolism.
Like mitochondria, peroxisomes are able to break down fats for energy. However,
when they do this, they produce 30-40% more energy as heat but 30% less energy
as ATP.
Since dietary omega-3s increase fat breakdown through peroxisomes, more fat
is burned to do the same daily activities when omega-3 intake is high. Unfortunately, omega-3 supplementation is not a magic fat loss method: The overall
impact is minor.
Body function
detoxify: To remove a poison or
toxin from the body
cholesterol: Synthesized in the
liver of humans and other animals.
A precursor of bile acids and steroid hormones
bile: A yellow or orange fluid produced by the liver, concentrated
and stored in the gallbladder, and
released into the small intestine
for fat digestion
ß: Beta, the second letter of greek
alphabet
prostaglandin: Class of physiologically active fatty acid compounds present in various tissues;
can have hormone-like effects
Let’s look now at how these cellular components, and the chemicals they make
and use, work together within the body.
Enzymes
Enzymes make up the largest group of proteins in the body. You can often spot
enzymes by their names, which typically end in “-ase”, such as:
•
lipase (enzymes that break down lipids);
•
protease (enzymes that break down proteins); or
•
amylase (enzymes that break down carbohydrates).
Enzymes are important biological catalysts, substances that jump-start and
speed up nearly every chemical reaction that occurs in the body.
Enzymes work by exposing their own “active sites” to connect with particular
molecules. Once the enzyme can hold these molecules in place, reactions can
occur. One model of this process is the lock-and-key model. In this model, the
catalyst: A substance that accelerates a chemical reaction
lock-and-key model: Model
that explains enzyme specificity
Products
Substrate
weakened
substrate bonds
active site
Enzyme
Enzyme-Substrate
Enzyme
Figure 1.6. Enzymes. Enzymes expose their own “active sites,” connecting with specific molecules. Holding these molecules in place, they allow reactions to occur, which
allows for product formation.
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induced fit model: Model that
suggests enzymes are rather flexible structures
enzyme and its chemical partner fit together tightly and carry out their reaction.
In another model, the induced fit model, the enzyme and chemical partner
undergo structural changes when close to one another, eventually fitting together
properly and starting the reaction. You can think of this like puzzle pieces that
change their shape when they are near each other.
No matter what model you apply, the key idea is that enzymes must somehow fit
and connect with their chemical partners. Lipase can only work with lipids; it can’t
work with proteins.
See Figure 1.6.
Many environmental, genetic, and nutritional factors — including temperature,
pH, substrate concentration, and vitamin and mineral status — influence how enzymes work. Thus, nutrition plays an important role in most enzymatic reactions.
Co-enzymes
co-enzyme: Non-protein compound that forms the active portion of an enzyme system
catalyze: Initiate or increase the
rate of a chemical reaction
Just like a co-pilot works with a pilot, co-enzymes work with enzymes. Coenzymes are non-protein molecules, made up wholly or partly of vitamins. We
need them for enzyme-catalyzed reactions.
For instance, pyridoxal phosphate, the active form of vitamin B6, acts as a co-enzyme in all transamination reactions, a particular kind of chemical reaction
involving amino acids. We’ll talk about these types of chemical reactions later in
the text.
And you may already have heard of co-enzyme Q10, which we mentioned earlier,
and which is involved in cellular respiration reactions.
Protein receptors
Protein receptors are found both in the plasma membrane and inside the cell.
As we’ve discussed, cell membranes help control what gets in and out of our
cells. They do this, in part, with membrane protein receptors that act like little
chemical gates.
signal transduction:
Conversion of one signal to another by a cell
Cells get information about their outside world by signal transduction. The
process is a little bit like the telephone game you played as a kid.
receptor-ligand binding complex: A complex formed between
a receptor and a substance to
allow for further cellular activity
A receptor on a cell binds to what is known as a ligand, forming a receptor-ligand
binding complex. A ligand attaches to its specific receptor and no other. The
ligand activates its receptor, which then activates a second messenger inside the
cell. Then the second messenger activates another second messenger, and so on
until the last second messenger goes into the nucleus and triggers changes in gene
expression that leads to some sort of cellular response.
ligand: An ion or molecule that
binds to another molecule or
metal atom
second messenger: Substance
that mediates intracellular activity
by relaying a signal from an extracellular molecule
An example of this process is our cellular response to insulin.
•
After we eat, insulin is released from our pancreas and travels through the
bloodstream.
•
From there, it can bind to specific, insulin-friendly protein receptors on the
membrane of our cells.
Nutrition: The Complete Guide
Cells | 41
Once bound, this connection signals to proteins inside the cells — usually called
second messengers — to get more channels to the membrane and accept glucose
more readily.
As we’ve stressed already, physical activity changes how our cells respond to
nutrients. Repeated muscular contractions (for instance, 30 minutes of pumping
our legs on a bike) tell the cell to move more protein receptors to the cell membrane. This helps glucose get into the cell more efficiently and effectively to help
refill the fuel tank.
What we eat can also influence second messengers. For instance, caffeine in
coffee / tea, theobromine in cacao, and theophylline in tea / cacao can all inhibit
phophodiesterase, an enzyme that breaks down second messengers in cells. So,
in the case of caffeine, this means stronger / faster heart muscle contractions,
greater blood vessel constriction, and enhanced stomach acid secretions.
Transport proteins
Transport proteins are also involved in cellular communication. These live in
cell membranes and let molecules pass between spaces inside the cells and spaces
outside of cells.
This movement across the plasma membrane can take place via one of two
mechanisms:
•
passive transport (which doesn’t need energy), or
•
active transport (which needs energy).
Active transport allows vitamins, minerals, glucose, and amino acids into cells. See
Figure 1.7
In the next unit, we’ll look at how some of these chemical processes and cellular
structures and tasks are involved in digestion.
Extracellular space
Intracellular space
Figure 1.7. Transport proteins. Transport proteins specifically allow the passage of
water-soluble molecules between the spaces inside the cells and the spaces outside the
cells. Movement across the plasma membrane can take place via one of two mechanisms:
facilitated diffusion or active transport. Cellular transport allows things like vitamins,
minerals, glucose and amino acids into cells.
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Nutrition in practice
Salivary amylase is an enzyme in saliva that starts the digestion of starch. It helps
to improve our “mouth experience” while eating (e.g., enhanced taste of certain
foods). We’ve known about it for over 100 years.
Just recently, researchers found a correlation between obesity and a person’s
ability to make amylase. People with fewer AMY1 genes — thanks to genetic
polymorphisms — might not tolerate carbohydrates as well. People whose
ancestors traditionally ate diets higher in starch seem to have more AMY1. This
is another example of the interaction between our environment, culture, genes,
and optimal dietary choices.
Cell types
In the next unit, you’ll meet some different cell types.
You’ll notice that many types end in the suffix “cyte.” This suffix will tell you that
something is a cell. (For more on this, see the “Language matters” sidebar.)
Each cell’s structure can tell you about its job. For instance:
•
Enterocytes, which line the intestine, are shaped like little brushes. This increases their surface area and helps them absorb nutrients.
columnar epithelial cells:
Pillar-shaped cells that line many
surfaces of the body
goblet cells: Mucus-secreting
epithelial cell that distends, taking
on the form of a goblet; found
often in respiratory and intestinal
tracts
•
Much of the gastrointestinal tract is lined with columnar epithelial cells.
These are tall skinny cells.
•
If their job is to absorb nutrients, there’s only one layer of them.
•
If their job is to secrete things (like saliva), they’re stacked on top of each other
like cases of beer. Stacked cells are known as stratified cells.
•
Some columnar epithelial cells are known as goblet cells because of their
shape.
•
Cuboidal, or cube-shaped cells, are found in the salivary glands and the lining
of the mouth. Because of their shape, they tend to be a little stronger and
tougher, so they’re often used as structural cells.
•
Squamous cells are flat cells that look a bit like layers of fish scales. They line the
esophagus and help protect it from stomach acid. They’re easily sloughed off
and replaced.
•
The structure of myocytes, or muscle cells, allows them to produce force in
order to move our body around.
There are many types of cells within the human body. You won’t learn them all.
Just get the general idea: Cells are not only diverse inside, they’re diverse outside
too. Each unique cell type and structure is adapted for a specific job.
Nutrition: The Complete Guide
Cells | 43
Language matters
Many of our English medical terms come from ancient Greek or Latin, or even
older sources. You’ll notice we often mention where these terms come from.
Obviously, you don’t have to brush up on the classics to become a nutrition
coach.
But you may find it helpful to understand where words come from, so that you
can guess at what an unfamiliar word might mean.
For instance:
“Entero” comes from the Greek enteron, or intestine.
“Hepatic” comes from the Greek hepatikos, or liver.
“Gastric” comes from the Greek gaster, or stomach.
“Cyte” comes from the ancient Greek kyto, which refers to a hollow or empty
container. We now use it to refer to cells.
“Epi” comes from the even more ancient Proto-Indo-European epi, meaning near,
at, or against.
So any time you see a form of these words, you’ll know what you’re dealing
with.
For instance, enterocytes are intestinal cells. Hepatocytes are liver cells. Epithelial
cells are cells that are the top layer of something, such as the innermost layer of
the esophagus.
This study of where words come from is known as etymology. This can give us
clues about what those words mean. It can also help you if English is not your
first language.
If you’re having trouble recalling a particular term in this course, try Googling
“etymology” and that term. You might learn a little factoid or two about that
term that helps it stick with you.
Get to know the language of your field and where it comes from, and you’ll
probably find that your understanding and comfort with the terminology improves. (And you’ll remember it better when tested!)
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Summary
The trillions of cells of the human body work together
to form tissues, organs, and organ systems. The total of
all of the activities taking place in these systems is what
most people refer to as “metabolism.”
There are many levels of organization in the body, from
microscopic atoms up to fully functional organisms (and
beyond, to ecosystems). These systems are interconnected, and all must work properly for organisms to thrive.
Our cells have many jobs, including:
•
converting nutrients into energy (particularly ATP)
•
making proteins (under the direction of our DNA)
•
moving those proteins, nutrients and other substanc-
as enzymes and co-enzymes, or protein receptors) to
begin and carry out chemical reactions; to send cell
signals; and / or to transport other molecules.
The food we eat interacts with the small chemical reactions and processes taking place in our cells.
Food thus affects our health in five ways. It:
1.
provides energy
2.
provides molecules involved in chemical reactions
3.
is incorporated into body structures
4.
influences chemicals such as hormones and
neurotransmitters
es around (including in and out of the cell across the
membrane) and
•
clearing waste and debris from the cell.
Our cells use specialized structures and molecules (such
Nutrition: The Complete Guide
5.
affects genetic protein-making signals as well as the
quality of the proteins that are made