Chapter 3
NUTRITION
Test your knowledge
 It is recommended that all adults consume 2 –
3 half – cup servings of fruits and vegetables
every day. True or false?
 FALSE. For someone consuming 2000 calories, 2
½ cups of vegetables and 2 cups of fruit are
recommended – a total of 9 half – cup servings.
Test your knowledge
 Candy is the leading source of added sugars
in the American Diet. True or False?
 FALSE. Regular (nondiet) sodas are the leading
source of added sugars and calories.
 Each 12-ounce soda supplies about 10 teaspoons
of sugar, or nearly 10% of the calories in a 2000 –
calorie diet.
Test your knowledge
 Which of the following is not a whole grain?
 Brown rice
 Wheat flour
 Popcorn
b. Unless labeled “whole wheat”, wheat flour is
processed to remove the bran and germ and is not a
whole grain.
Nutrition Requirements:
Components of a healthy diet
 7 essential nutrients of a healthy diet
 Protein
 Fat (lipids)
 Carbohydrates
Macronutrients
 Fiber
 Water
 Vitamins
 Minerals
Micronutrients
Energy in foods is expressed
in kilocalories
 1 calorie = amount of heat needed to raise the temperature of 1
liter of water 1°C.
 A person needs about 2000 kilocalories a day to meet energy
needs.
 Kilocalories are also known as calories, but 1 calorie = 1000
kilocalories.
 Of the essential nutrients, three supply with energy:
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Fat = 9 calories per gram
Protein = 4 calories per gram
Carbohydrate = 4 calories per gram.
Alcohol (not essential) = 7 calories per gram.
Nutrients are released into
the body through the process
of digestion
Proteins
 Important part of the
body’s muscles and
bones
 Also form part of blood,
enzymes, cell
membranes and some
hormones.
 Amino acids are the
basic building block of
proteins
Proteins
 20 amino acids are
found in food
 9 of them are essential:
hisidine, isoleucine,
lysine, methionine,
phenylalanine,
threonine, tryptophan,
and valine.
 The other 11 can be
produced by the body.
 Types:
 Complete: if they supply all the
essential amino acids
 Incomplete: if they do not supply all the
essential amino acids.
Recommended protein intake
 10 – 35% of total daily calories.
 0,8 gram per kilogram of body weight
 50 gr  140 pounds
 65 gr  180 pounds.
 Problems of an excess protein intake
 Excess protein is synthesized into fat
 A very high protein intake can strain the kidneys
and lead to dehydration
Fats
 Stored in your body represent usable energy
 Help to insulate the body
 Provide support and cushion for organs
 Help to absorb fat-soluble vitamins
 Add flavor and texture to foods
 Linoleic acid and alphalinoleic acid are essential to regulate
blood pressure and progress of a healthy pregnancy.
Fats
 Types:
 triglycerides
 Saturated solid
Animal sources
Hydrogenation
 Unsaturated liquid
Plant sources
(linoleic – alpha-linoleic acids)
 Monounsaturated
 Polyunsaturated
Fats and health
 Saturated fats
 LDL (low density lipoprotein  bad cholesterol
 Red meats, solid fats
 Unsaturated fats
 HDL (high density lipoprotein)  good
chlolesterol
 Avocados, nuts, olive and canola oil, fish (omega 3
fatty acids)
Recommended Fat Intake
 Total fats should not exceed 20 – 30 % of the
total calories.
 3 – 4 teaspoons of vegetable oil per day
Carbohydrates
 Needed primarily to supply energy to body
cells
 Cells of the nervous system and blood use
only energy from carbohydrates.
 During intense exercise muscle cells get most
of their energy from carbohydrates.
Carbohydrates
 Types:
 Simple
 One or two sugar units in each molecule
 Found naturally on fruits and milk
 Sucrose, fructose, maltose, lactose
 Complex
 Long chains of sugar molecules
 Found in tubers, fruits, vegetables and grains
 Starches, dietary grains
Refined carbohydrates vs.
whole grains
 Whole grains
 Consist of an inner layer of
germ, a middle layer
(endosperm) and an outer layer
of bran.
 Rich in nutrients
 Refined carbohydrates
 Germ and bran are removed leaving the starchy
endosperm.
 Lower in fiber, vitamins, minerals and other beneficial
compounds.
Recommended carbohydrate
intake
 40 – 45% of total daily calories
 225 – 325 grams of carbohydrates for a 2000
calories diet.
 Athletes in training should have a 60 – 70% of
total daily calories.
FIBER
 Non-digestible
carbohydrates
 Found mainly in
plants
 Provide bulk for feces
in the large intestine,
which in turn facilitate
elimination.
Types of fiber
 Dietary fiber: non-digestible
carbohydrates and lignin found in grains, legumes and
vegetables
 Functional fiber: non-digestible carbohydrates isolated from
natural sources or synthesized in a lab and added to food
 Total fiber: sum of dietary and functional fiber.
 Soluble: slows the body’s absorption of glucose and binds cholesterol –
containing compounds
 Insoluble: binds water making the feces bulkier and softer so they pass
easily through the intestines.
Vitamins
 Organic substances
 Required in small amounts to regulate
processes within living cells
 Humans need 13 vitamins
 4 Fat soluble (A, D, E, K)
 9 Water soluble (C and 8 B – complex vitamins)
Functions of vitamins
 Help chemical reactions to take place
 Help unleash energy stored in carbohydrates,
proteins and fats.
 Production of red blood cells
 Maintenance of nervous, skeletal and immune
systems
 Antioxidants: preserve healthy cells.
Sources of vitamins
 Fruits
 Vegetables
 Grains
 Processed food
 Flour
 Breakfast cereals
 Skin exposed to sunlight (D)
 Intestinal bacteria (K)
Vitamins and disease
 DEFICIENCIES
 Vitamin A  blindness
 Vitamin B 6  seizures
 Folate  babies with neural tube defect
 Vitamins B 6, B- 12 and folate  heart disease risk
 EXTRA VITAMINS
 Vitamin A  increase the risk of birth defects
 Vitamin B-6  irreversible nerve damage
Minerals
 Inorganic elements
 17 essential minerals
 Needed in small amounts to regulate body
functions
 Aid in the growth and maintenance of body
tissues
 Help release energy
Sources of minerals
 Lean meats  iron
 Dairy products  calcium
 Whole grains and leafy vegetables 
magnesium
 Spinach, bananas, mushrooms, white and
sweet potatoes  potassium
Water
 The human body contains 50 – 60% of water
 Medium in which most chemical reactions take
place
 Transports substances around the body
 Lubricant
 Helps to regulate body temperature
Recommended intake of water
 Men  3,7 liters of water
3,0 coming from beverages
 Woman  2,7 liters of water
2,3 coming from beverages
Other substances in food
 Antioxidants
 Protects the body from the action of free radicals
and repair the damage they cause
 Phytochemicals
 Prevent chronic diseases.
 Lower chlesterol levels
 Boost the activity of cancer – fighting immune
cells
 Reduce the effects of carcinogenic compounds.
Suplements
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Suplements might lack potentially beneficial
phytochemicals that are found only in whole
foods.
 Some vitamins and minerals are dangerous
when ingested in excess
 Might affect the absorption of other vitamins
or minerals
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Recommended for:
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Pregnant woman
People over age 50
Smokers
Woman with heavy menstrual flows
Vegetarians (depending on their food choices))
People with certain diseases or that take certain
medications.
Your nutritional needs can be obtained
primarily from food.
NUTRITIONAL GUIDELINES:
 DRIs: dietary reference intakes
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Recommended intake levels for
vitamins, minerals, and
macronutrients
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RDAs : recommended dietary allowances
 Focused on preventing nutritional
deficiency diseases
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AI: Adequate Intake
 Set when there is to enough information
available to set an RDA value.
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UL: Tolerable upper intake level
 Sets maximum daily intake by a healthy
person that is unlikely to cause health
problems.
NUTRITIONAL GUIDELINES
 Daily values
 Used as a basis for food labels
 Based on several sets of guidelines
 Includes standards for fat, cholesterol,
carbohydrates, dietary fiber and
selected vitamins and minerals.
 Represent the appropriate intake
levels for a 2000 calorie diet.
NUTRITIONAL GUIDELINES
 Dietary guidelines for Americans
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Issued by the US Department of Agriculture
and the Department of Health and Human
Services.
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Provides general guidance for choosing a
healthy diet.
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Its guidelines include:
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Nutritional recommendations
Weight management recommendations
Physical activity recommendations
Encourages certain food groups: fruits,
vegetables, whole grains, an low fat or fat
free milk products.
 Recommends to reduce the use of certain
substances such as sodium and alcoholic
beverages.
NUTRITIONAL GUIDELINES
 USDA’s My Pyramid
 Overall food guidance system
 Developed to remind consumers to make healthy
food choices and to be active everyday
1992
2005
USDA’s MY PYRAMID
 Color bands represent that all
food groups are needed
each day for health.
 Food groups are color coded:
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Grain group
Vegetable group
Fruit group
Milk group
Meat and bean group
Oils are not considered as a food group
 Differing widths of the color
bands suggest about how
much food should be eaten
from each group.
Pg 80
 Food group bands narrow
from bottom to top suggesting
to eat nutrient-dense forms of
foods.
 Steps and person on them
symbolize that physical
activity
should be a part of
everyday healthy living.
 The slogan “Steps to a
Healthier You” suggests that
improvement should happen
in stages, over time.
Meeting varied needs
 My Pyramid and the Dietary Guidelines for
Americans provide a basis that everyone can use
to create a healthy diet. However, some
population groups face special dietary challenges:
 Special population groups—woman, men, college
students, older adults, athletes and people with special
health concerns.
 Food preferences—Vegetarian, lactose-intolerant,
ethnic
 Situations—Eating out, carrying in, cooking at home
Nutritional planning: making
informed choices about food
Reading food labels
Food additives
 Uses:
 Maintain or improve nutritional
quality
 Maintain freshness
 Help in process or preparation
 Alter taste or appearance
 Most used:
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Salt
Sugar
Corn syrup
Citric acid
Baking soda
Vegetable colors
Mustard
Pepper
 Additives of potential
concern:
 Sulfites  keep vegetables
from turning brown, cause
severe reactions in some
people
 Monosodium glutamate 
flavor enhancer, some people
experiences episodes of
sweating and increased blood
pressure.
Food borne illness
 Caused by pathogens found in food
 Raw or undercooked animal products such as
chicken, hamburger, oysters, eggs.
 Drinking water, fruits
 Symptoms include acute gastroenteritis,
diarrhea, vomiting, fever and weakness.
Irradiated food
 Food can be treated with
gamma rays, X-rays or highvoltage electrons to kill
potentially harmful
pathogens.
 Irradiation kills most
pathogens, but it does not
completely sterilize foods
Environmental contaminants
and organic foods
 Certified organic goods meet strict production, processing,
handling and labeling criteria.
 For plant products
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Must limit pesticide residues
No sewage sludge
 For animal products:
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Feed with organic products
Access to outdoors
No use of antibiotics or hormones
No genetic engineering, ionizing, radiation.
 Organic products might not be chemical free
Products with higher pesticide
residues
Products with little pesticide
residue
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Apples,
Peppers
Celery
Cherries
Imported grapes
Necttarines
Peaches
Pears
Potatoes
Red raspberries
Spinach
Strawberries
Asparagus
Avocados
Bananas
Brocoli
Cauliflower
Corn
Kiwi
Mangoes
Onions
Papaya
Pineapples
Peas
Remember…
 No single type of diet provides optimal health
for everyone
 Many cultural dietary patterns can meet
people’s nutritional requirements
 Customize your food plan based on your age,
gender, weight, activity level, medical risk
factors and personal tastes
Lab 3.3 Informed food
choices
 Choose three food items to
evaluate.
 You might want to select three
similar items, such as regular, lowfat and non fat salad dressing or
three very different items.
 Record the information from their
food labels in the table.
Lab 3.1.
 List your daily menu
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During a regular week day
During a weekend.
Use apendix B to guide you
Or MyPyramid.gov
MyPyramid Tracker
 Use figure 3,7 to compare your results to the
recommendations of MyPyramid for a 2000 calories
diet
 Compare your results and evaluate what changes
should you make to improve your diet.