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ACE Group Fitness Instructor Manual
Chapter
4
 Introduction
to Nutrition
1
Scope of practice

As a fitness professional, it is within your
scope to make dietary suggestions using:

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
MyPyramid Food Guidance System
www.MyPyramid.gov
2005 Dietary Guidelines for Americans
www.nal.usda.gov/fnic
This information updates the Food Guide
Pyramid released in 1992 and the 2000 Dietary
Guidelines for Healthy Americans.
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Dietary guidelines



The 2005 Dietary Guidelines for
Americans and MyPyramid Food
Guidance System provide
individualized nutrition
recommendations for a healthy diet.
The Dietary Guidelines are the
government’s best advice on how to
eat to promote health and prevent
chronic diseases such as
cardiovascular disease, stroke,
hypertension, diabetes, osteoporosis,
and some cancers.
The 2005 guidelines also emphasize
physical activity and decreasing
caloric consumption for weight
control.
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Dietary guidelines

Physical Activity
Recommendations from the
2005 Dietary Guidelines for
Americans:


To reduce the risk of chronic disease
in adulthood, engage in at least 30
minutes of moderate-intensity
physical activity, above usual
activity, at work or home on most
days of the week.
For most people, greater health
benefits can be obtained by
engaging in physical activity of more
vigorous intensity or longer
duration.
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Dietary guidelines

Physical Activity Recommendations
from the 2005 Dietary Guidelines
for Americans:


To help manage body weight and
prevent gradual, unhealthy body weight
gain in adulthood, engage in
approximately 60 minutes of moderateto vigorous-intensity activity on most
days of the week while not exceeding
caloric intake requirements.
To sustain weight loss in adulthood,
participate in at least 60 to 90 minutes
of daily moderate-intensity physical
activity while not exceeding caloric
intake requirements.
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USDA and DASH guidelines
Amounts based on a 2,000-calorie daily diet
All servings are per day unless otherwise noted
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New Food Guidance System
7
MyPyramid approximate daily energy intakes
1,600 calories:
Sedentary older adults
2,200 calories:
Active teenage girls, active women, and
sedentary men
2,800 calories:
Active teenage boys, active men, and
very active women
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Macronutrients


Protein, carbohydrate, and fat are
the three nutrients that provide
calories. (Alcohol also provides
calories, but is not considered an
essential part of the diet.)

1 gram protein = 4 calories

1 gram carbohydrate = 4 calories

1 gram fat = 9 calories

1 gram alcohol = 7 calories
These calories are used by the body
to sustain life by helping to maintain
body temperature and by facilitating
the growth and repair of all organs
and tissues.
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Protein

Proteins are organic substances containing
carbon, oxygen, hydrogen, and nitrogen.

Each protein molecule is made up amino acids.

Twenty different amino acids are found in the body, all but 8 to
10 of which can be manufactured by the body.

Those the body cannot make are called “essential” amino acids
and must be consumed through the diet.



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Meat, fish, poultry, and dairy products contain all of the
essential amino acids and are, therefore, considered complete
proteins.
Vegetables, grains, and nuts do not provide all of the essential
amino acids; however, these incomplete protein foods can be
combined to get all of the essential amino acids.
Protein is the body’s major building material. The
brain, muscles, skin, hair, and connective tissue
are all composed primarily of protein.
Protein is needed to make the enzymes and
hormones that regulate such body processes as
water balance and serve as critical components of
the antibodies that fight foreign organisms.
Protein can be used as a source of energy, but
only when the diet is limited in carbohydrates and
fats.
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Carbohydrate


Carbohydrates are divided into two types—
complex and simple.
Complex carbohydrates (or starches), such as
bread, rice, cereal, and potatoes, take longer
for the body to break down.


Simple sugars, which are rapidly digested and
absorbed, are found in foods such as fruit and
milk, which provide vitamins and minerals.


These foods also can provide fiber and other
vitamins and minerals.
Most simple sugars, however, come in the form
of soft drinks, cakes, cookies, and candy, and
provide little more than calories.
As carbohydrate foods make their way
through the digestive system, they are broken
down into glucose — the only form of
carbohydrate that the body can use directly
for energy.

Glucose can be stored in the liver and muscles,
where it is transformed to glycogen and used as
an energy source during exercise.
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Fiber

Fiber, the indigestible part of a carbohydrate,
makes up the cell wall of all plant foods.

Soluble fiber
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
Soluble fibers form a gel in water and are composed primarily of
pectin and guar gums.

Soluble fiber may help reduce blood cholesterol and blood
glucose.
Insoluble fiber
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Insoluble fibers are composed of cellulose and add bulk to the
diet.
Insoluble fiber is important for proper bowel function and can
reduce symptoms of chronic constipation, diverticulosis, and
hemorrhoids.
Most fiber-containing foods have a combination of
both types of fibers.
Eating a high-fiber diet (25 to 35 grams of fiber per
day) may help to reduce the risk of heart disease,
cancer, diabetes, and diverticulosis.
High-fiber foods can help with weight control, since
fiber swells with water, giving people a more
satisfied feeling. Also, soluble fiber lingers in the
stomach, helping one feel full.
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Fat


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Fat is a source of energy, supplying the fatty acids
necessary for many of the body’s activities.
Fats are essential for carrying the fat-soluble
vitamins as well as serving to enhance the flavor,
aroma, and texture of foods.
Saturated fats generally come from animal sources
(meats and dairy) and are solid at room
temperature.



Saturated fats interfere with the removal of cholesterol
from the blood.
Polyunsaturated fats come from plant sources and
are liquid at room temperature.

Examples include corn, safflower, and sunflower oils.

They tend to lower cholesterol in the blood by lowering
the level of LDL.

One drawback to polyunsaturated fats is that they also
lower the level of HDL, the so-called good cholesterol.
Monounsaturated fats also are liquid at room
temperature and are found in peanut, canola, and
olive oils.

These fats reduce total blood cholesterol by lowering
the LDL while keeping the HDL stable.
13
Micronutrients

Vitamins

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Organic, non-caloric nutrients essential for
normal physiologic function
Vitamins must be consumed through food
with only three exceptions: vitamin K and
biotin can be produced by normal intestinal
flora and vitamin D can be self-produced with
sun exposure.
A variety of nutrient-dense foods must be
consumed to assure adequate vitamin
intakes.
Humans need 13 different vitamins, which
are divided into two categories: water-soluble
vitamins and fat-soluble vitamins.

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Thiamin, riboflavin, niacin, pantothenic acid,
folate, vitamin B6, vitamin B12, biotin, and
vitamin C are the water-soluble vitamins.
Vitamins A, D, E, and K are the fat-soluble
vitamins.
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Micronutrients

Minerals

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Inorganic, non-caloric nutrients that serve to
regulate enzyme activity, maintain acid-base
balance, and assist with strength development
and growth
Unlike vitamins, many minerals are found in the
body as well as in food.
An important consideration when consuming
minerals, and particularly when taking mineral
supplements, is the possibility of mineral–
mineral interactions.
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Minerals can interfere with the absorption of other
minerals.
For example, zinc absorption may be decreased
through iron supplementation.
Zinc excesses can decrease copper absorption.
Too much calcium limits the absorption of manganese,
zinc, and iron.
When a mineral is not absorbed properly, a
deficiency may develop.
15
Energy balance equations

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Neutral calorie balance

Calories consumed = calories expended

No change in weight
Positive calorie balance

Calories consumed > calories expended

Results in weight gain
Negative calorie balance

Calories consumed < calories expended

Results in weight loss
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Recommended rates of weight loss

Regular exercise and proper nutrition result in
the best long-term weight loss.

One pound of fat = 3,500 calories

For realistic weight loss, ACSM suggests:


Expending 300–400 calories per workout session

Exercising a minimum of 3 days per week

Creating a deficit of 500–1000 calories per day
An average person can expect to lose 1 to 2
pounds per week.

An obese person can expect to lose 1 to 3
pounds per week initially, and then taper off to
1 to 2 pounds per week.
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National Institutes of Health recommendations

Use healthy eating plans that reduce
calories but do not rule out specific foods
or food groups.

Engage in regular physical activity.

Learn tips on healthy behavior changes
that also consider cultural needs.


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Follow a plan of slow and steady weight
loss of no more than 3 pounds per week
(however, weight loss may be faster at the
start of a program).
Consult your physician if you are planning
to lose weight by following a special
formula diet, such as a very-low-calorie
diet.
Have a plan to keep off the weight after
you have lost it.
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