An Overview
of Nutrition
Chapter #1
Nutrition in
Your Life
Section #1.1
Section Introduction
 Believe
it or not, you have probably eaten
at 20, 000 meals in your life. Without any
conscious effort on your part, your body
uses the nutrients from those foods to
make all its components, fuel all its
activities, and defend itself against
diseases. How successfully your body
handles these tasks depends, in part, on
your food choices. Nutritious food
choices support healthy bodies.
Nutrition in Your Life

Nutrition:


The science of foods and the nutrients and
other substances they contain, and of their
actions within the body.
Foods:


Products derived from plants or animals that
can be taken into the body to yield energy and
nutrients for the maintenance of life and the
growth and repair of tissues.
Diet:

The foods and beverages a person eats and
drinks.
Food Choices

People decide what to eat, when to eat, and even
whether to eat in highly personal ways, often based
on behavioral or social motives, including:










Personal Preference
Habit
Ethnic Heritage or Tradition
Social Interactions
Availability, Convenience, and Economy
Positive and Negative Associations
Emotional Comfort
Values
Body Weight and Image
Nutrition and Health Benefits

Functional Foods:

Foods that provide health benefits beyond their nutrient
contributions.
The Nutrients
Section #1.2
The Nutrients
 Nutrients:


Chemical substances obtained from food
and used in the body to provide energy,
structural materials, and regulating agents
to support growth, maintenance, and
repair of the body’s tissues.
Energy:
 The
capacity to do work.
Nutrients in Foods and in the Body

Composition of Foods:

Phytochemicals:


Non-nutrient compounds found in plant-derived foods that have
biological activity in the body.
Non-nutrients:



Composition of the Body
Chemical Composition of Nutrients:

Inorganic:


Not containing carbon or pertaining to living things.
Organic:


Compounds in foods that do not fit within the 6 classes of nutrients.
A substance or molecule containing carbon-carbon bonds or
carbon-hydrogen bonds.
Essential Nutrients:

Nutrients a person must obtain from food because the body
cannot make them for itself in sufficient quantity to meet
physiological needs.
Energy-Yielding Nutrients

Energy-Yielding Nutrients:


The Energy-Yield Nutrients:




The nutrients that break down to yield energy
the body can use.
Carbohydrates
Fats
Proteins
In addition to providing energy, these
nutrients also provide the raw materials for
building the body’s tissues and regulating its
many activities.
How Food Energy is Measured

Energy Measured in kCalories

Calories:


The amount of energy a food provides depends
on how much carbohydrate, fat, and protein it
contains.

Energy Density:


Units by which energy is measured.
A measure of the energy a food provides relative to
the amount of food.
When the body uses energy-yielding nutrients, the
bonds between the nutrient’s atoms break
causing them to release energy.
kCalorie Values of Energy Nutrients
Energy Nutrient
kCalories (per gram)
Carbohydrate
4 kcal/ gram
Fat
9 kcal/ gram
Protein
4 kcal/ gram
How to Calculate Food Energy
1.
2.
3.
4.
5.
6.
Multiply the number of grams of
carbohydrate by 4.
Multiply the number of grams of protein by 4.
Multiply the number of grams of fat by 9.
Add the results from 1-3 together.
Divide each amount of energy nutrients by
the total calories in the food.
Multiply each by 100 to get the percentage.
Example: Calculating Food Energy
1
slice of bread with 1 Tbsp. of peanut
butter on it contains 16 grams
carbohydrate, 7 grams of protein, and 9
grams of fat.
16 g x 4kcal/gram = 64 kcal
7 g x 4kcal/ gram = 28 kcal
9 g x 9kcal/ gram = 81 kcal
64 + 28 + 81 = 173 kcal
64 / 173 = .369 (.37) 37%
28 / 173 = .16 16%
81 / 173 = .468 (.47) 47%
The Vitamins
 Vitamins:

Organic, essential nutrients required in small
amounts by the body for health.
 There
are 13 different vitamins, each with
its own special role to play.
 Vitamins can only function if they are
intact.
The Minerals
 Minerals:

Inorganic elements which may be essential
nutrients required in small amount by the
body for health.
 16
minerals are known to be essential in
human nutrition.
 Because minerals are inorganic, they are
indestructible and do not need to be
handled with special care.
Water
 Participates
in metabolic reactions.
 Supplies the medium for transporting vital
materials to cells and waste products
away from them.
The Science
of Nutrition
Section #1.3
The Science of Nutrition

Nutrition:



The study of the nutrients and other substances in
foods and the body’s handling of them.
The foundation of nutrition depends on biology,
biochemistry, and physiology.
The science of nutrition is growing as scientists
apply knowledge gained from sequencing the
human genome which is leading to nutritional
genomics.

Genome:


The full complement of genetic material in the
chromosomes of a cell.
Nutritional Genomics:

The science of how nutrients affect the activities of
genes and how genes affect the activities of nutrients.
Nutrition Research


Researchers use the
scientific method to
guide their work.
Hypothesis:


Observation &
Question
Hypothesis &
Prediction
An unproven statement
that tentatively explains
the relationships
between two or more
variables.
Experiment
Results &
Interpretations
Theory:

A tentative explanation
that integrates many
and diverse findings to
further the
understanding of a
defined topic.
Hypothesis
Supported
Hypothesis Not
Supported
Theory
New Observations
& Questions
The Control

Subjects:


The people or animals participating in a
research project.
Subjects are typically divided into 2 groups:

Experimental Group:


A group of individuals similar in all possible respects
to the control group except for the treatment.
Control Group:


A group of individuals similar in all possible respects
to the experimental group except for the treatment.
Research participants get placed in either the
control or experimental group through
randomization.

Randomization:

A process of choosing the members of the experimental and
control groups without bias.
Aspects of Nutrition Research


Sample Size
Placebos:


An inert, harmless medication given to provide comfort and
hope; a sham treatment used in controlled research studies.
Placebo Effect:


The result of expectations in the effectiveness of a medicine, even
medicine without pharmaceutical effects.
Double Blind Experiment:


An experiment in which neither the subjects nor the researchers
know which subjects are members of the experimental group
and which are serving as control subjects, until after the
experiment is over.
Blind Experiment:

An experiment in which the subjects do not know whether they
are members of the experimental group or the control group.
Aspects of Nutrition Research
(continued)

Correlations and Causes:

Correlation:


The simultaneous increase, decrease, or change in two
variables.
Variables:


Positive Correlation:


Occurs only if one variable increases and the other decreases.
Replication:


Occurs only if both variables increase or decrease.
Negative Correlation:


Factors that change.
Repeating an experiment and getting the same results.
Peer-Review:

A process in which a panel of scientists rigorously
evaluate a research study to assure that the scientific
method was followed.
Research vs. Rumors

Validity:


Having the quality of being founded on fact or
evidence.
To determine if a claim is actual research or a rumor,
ask yourself the following:







Who participated in the study, and how were they
selected?
Were the control and experimental groups similar?
Was the sample size large enough to rule out chance
variation?
Was a placebo effectively administered?
Was the experiment double blind?
Were the variables selected appropriately and
measured accurately?
Do the data support the conclusions?
Dietary
Reference
Intakes (DRI)
Section #1.3
Dietary Reference Intakes (DRI)
 Dietary

A set of nutrient intake values for healthy
people in the United States and Canada.
 DRIs




References Intakes (DRIs):
include:
Estimated Average Requirements (EAR)
Recommended Dietary Allowances (RDA)
Adequate Intakes (AI)
Tolerable Upper Intake Levels (UL)
Establishing Nutrient Recommendations

Estimated Average Requirements (EAR):


Recommended Dietary Allowances (RDA):


The average daily amount of a nutrient considered
adequate to meet the known nutrient needs of
practically all healthy people.
Adequate Intakes (AI):


The average daily amount of a nutrient that will maintain
a specific biochemical or physiological function in half
the healthy people of a given age and gender group.
The average daily amount of a nutrient that appears
sufficient to maintain a specified criterion.
Tolerable Upper Intake Levels (UL):

The maximum daily amount of a nutrient that appears
safe for most healthy people and beyond which there is
an increased risk of adverse health effects.
Establishing Energy Requirements

Estimated Energy Requirement (EER):


The average dietary energy intake that maintains
energy balance and good health in a person of a
given age, gender, weight, height, and level of
physical activity.
Acceptable Macronutrient Distribution Ranges
(AMDR):


Ranges of intakes for the energy nutrients that
provide adequate energy and nutrients and
reduce the risk of chronic diseases.
AMDRs:



Carbohydrate: 45% to 65%
Lipid: 20% to 35%
Protein: 10% to 35%
Using Nutrient Recommendations





Adequate energy and nutrient intakes apply
to healthy people only.
Recommendations are not minimum
requirements, or optimal intakes for all
individuals.
Most nutrient goals are intended to be met
through diets composed of a variety of foods.
Recommendations apply to average daily
intakes.
Each DRI category serves a unique purpose.
Nutrition
Assessment
Section #1.4
Nutrition Assessment

When a person doesn’t get enough or gets too
much of a nutrient or energy over an extended
period of time, that person can start to show signs
of malnutrition, undernutrition, or overnutrition.

Malnutrition:


Undernutrition:


Any conditions caused by excess or deficient food
energy or nutrient intake or by an imbalance of
nutrients.
Deficient energy or nutrients.
Overnutrition:

Excess energy or nutrients.
Nutrition Assessment of Individuals

To prepare a nutrition assessment, a registered
dietician or other trained healthy care professional
uses:


Historical Information
Anthropometric Data

Anthropometric:




Relating to measurement of the physical characteristics of
the body, such as height and weight.
Physical Examinations
Laboratory Tests
Nutrition Assessment:

A comprehensive analysis of a person’s nutrition
status that uses health, socioeconomic, drug, and
diet histories.
Nutrition Assessment of Populations


To assess a population’s nutrition status,
researchers conduct surveys using techniques
similar to those used on individuals.
The data collected are then used by various
agencies for numerous purposes, including
the development of national health goals.

Healthy People:


A national public health initiative under the
jurisdiction of the U.S. Department of Health
and Human Services that identifies the most
significant preventable threats to health and
focuses efforts toward eliminating them.
The data is collected through national
nutrition surveys.
Diet and
Health
Section #1.5
Diet and Health
 Diet
has always played a vital role in
supporting health.
 Recently, nutrition research has focused
on chronic diseases associated with
energy and nutrient excesses.

Chronic Disease:
 Diseases
characterized by a slow progression
and long duration.
Risk Factors for Chronic Diseases
 Risk

Factor:
A condition or
behavior
associated with an
elevated
frequency of a
disease but not
proved to be
causal.
Risk Factor
% of
Deaths
Tobacco
20%
Poor Diet/ Inactivity
14%
Alcohol
6%
Microbial Agents
4%
Pollutants/ Toxins
3%
Firearms
2%
Sexual Behavior
1%
Motor Vehicles
1%
Illicit Drugs
1%
Bibliography
 “Understanding
Nutrition, 10th Ed.” Rolfes,
S.R., Whitney, E. (2005). ThomsonWadsworth; Belmont, CA.