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Fats
Chapter 4
Fats
Chapter Objectives
1. Explain the importance of fats.
2. Define fats.
3. Explain how lipids (fats) are classified.
4. Learn how much fat is recommended in an athlete's diet.
5. Identify foods that contain fat.
6. Explain how the percentage of calories from fat can be calculated for specific foods.
7. Discuss the importance of cholesterol.
8. Identify the guidelines for a cholesterol-lowering diet for athletes.
9. Explain how fats can affect daily training and competitive performance.
10. Discuss what type, how much, and when fats should be consumed before exercise.
11. Discuss what type, how much, and when fats should be consumed during exercise.
12. Discuss what type, how much, and when fats should be consumed after exercise.
Chapter Outline
I. What's the big deal about fats?
A. Fats are an important nutrient for both athletes and nonathletes.
1. They serve as a primary energy source at rest and during exercise of light to
moderate intensity.
2. Dietary fat provides the essential fatty acids required for normal physiological
functioning of the body.
3. Fats add flavor to foods.
4. Fats are calorie dense and capable of meeting the high daily energy needs of
athletes.
B. Fat is often maligned because of the well-known association of cholesterol and
saturated fats with heart disease.
1. The thought of body fat raises negative feelings, particularly in athletes, who
are aware of the potential impact excessive levels of body fat can have on sport
performance.
2. The purpose of this chapter is to provide the reader with the knowledge
required to keep a healthy and informed perspective on an essential nutrient that is
often feared and shrouded in misconceptions.
II. What are fats?
A. Fats are molecules that belong in a group of compounds known as lipids.
1. Lipids are organic, carbon-containing compounds that are hydrophobic (water
insoluble), lipophilic (fat soluble), and feel greasy to the touch.
2. Lipids are an energy-rich nutrient, yielding 9 calories per gram.
3. Lipids are found in foods of both plant and animal origin.
B. Nonlipid molecules can be converted into lipids within the body: Carbohydrates or
proteins consumed in excess will be converted into lipids and stored in adipose tissue for
later use as energy.
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III. How are lipids (fats) classified?
A. The most important lipids fall into three main categories based on their molecular
structure: triglycerides, phospholipids, and sterols.
B. Triglycerides
1. Characteristics
a. Make up the majority of lipids found within the body and in foods and
beverages (for this text, triglyceride = fat).
b. Provide much of the flavor and texture in foods.
c. Serve as the major energy reserve for the body. Fats are stored in
adipocytes, liver, and muscle.
2. Molecular structure
a. Triglycerides are a combination of glycerol and three fatty acids.
b. The glycerol "backbone" of a triglyceride molecule is always constant;
however, the three fatty acids attached to the glycerol may differ (see
Figure 4.1).
c. A diglyceride consists of a glycerol backbone and two fatty acids.
d. A monoglyceride consists of a glycerol backbone and one fatty acid.
3. Triglycerides serve a number of functions in the body (considered an essential
nutrient) (see pages 101–102).
a. Triglycerides serve as an important source of energy at rest and during
exercise.
b. Fats serve as an abundant energy reserve for the body (Table 4.1).
c. Visceral and subcutaneous fats provide protection for vital organs and
serve as a thermal and electrical insulator in the body.
d. Fats play an important role as carriers of substances (e.g., fat-soluble
vitamins) into the body and within the bloodstream.
e. Fats enhance the sensory qualities of foods.
f. Fat consumption at meals or snacks can enhance satiety.
4. What are fatty acids?
a. Fatty acids have carbon atoms linked in a chainlike fashion.
b. All fatty acids have an organic acid group or carboxyl acid (COOH) at
one end and a methyl (CH3) group at the other end (Figure 4.2).
c. The carboxyl group is the alpha end and the methyl group is the omega
end of the fatty acid.
d. Fatty acids are classified as short-chain fatty acids (SCFAs), mediumchain fatty acids (MCFAs), and long-chain fatty acids (LCFAs) (Figure
4.3).
e. When the carbons in a fatty acid chain are linked by single bonds and
the remaining two bonds are filled with hydrogen, the fatty acid is said to
be saturated.
f. Unsaturated fatty acids have one or more double bonds between carbons
in the chain.
1. A monounsaturated fatty acid (MUFA) has one double bond in
its carbon chain.
2. A polyunsaturated fatty acid (PUFA) has two or more double
bonds (Figure 4.4).
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g. Hydrogenation is a chemical process in which hydrogen atoms are
added to unsaturated fatty acids, causing the previously unsaturated fat to
become saturated.
h. All foods contain a combination of unsaturated and saturated fats (Table
4.2).
i. Saturated fats have been implicated in cardiovascular disease because
they contribute to atherosclerosis, the buildup of fatty plaques on the
interior arterial walls, particularly in the arteries of the heart and neck.
Reducing saturated fat intake by decreasing total fat intake and
substituting mono- and polyunsaturated fats in the diet is recommended to
reduce the risk of cardiovascular disease.
j. In the trans position, the hydrogen atoms on either side of the double
bond are on opposite sides of the carbon chain, and thus the fatty acid is
straight rather than bent (Figure 4.5). The problem with trans fats is that
recent studies have implicated them with high blood cholesterol levels.
k. The methyl end of a fatty acid is the omega end. The double bond that
occurs closest to this end identifies the omega classification. Omega-3,
omega-6, and omega-9 classifications signify that the first double bond
from the omega end is at the third, sixth, or ninth carbons, respectively.
l. Linoleic acid (an omega-6 fatty acid) and linolenic acid (an omega-3
fatty acid) are considered essential fatty acids because the body cannot
manufacture them.
1. The AI for linoleic acid is 17 g/day for men aged 19 to 50 years
(14 g/day for 50+ years) and 12 g/day for women aged 19 to 50
years (11 g/day for 50+ years).
2. The AI for linolenic acid is 1.6 g/day and 1.1 g/day for men and
women aged 19 and older, respectively.
m. Dietary recommendations for adequate intake of essential fatty acids
are met if fat comprises approximately 5% of total calorie intake.
C. Phospholipids
1. Characteristics
a. Found in both plants and animals.
b. Are both water soluble and fat soluble.
c. Constitute the cell membranes of various tissues throughout the body.
d. Phospholipids are not essential, because the body can readily synthesize
them when needed.
2. Phospholipids have a glycerol backbone with two fatty acids and a phosphate
group (see Figure 4.6).
3. Phospholipids have a number of functions both inside and outside the body.
a. Because of their unique structure, phospholipids are ideal emulsifiers.
Emulsifiers keep fat-soluble substances suspended in a watery
environment.
b. Phospholipids are a major component of cell membranes.
c. Phospholipids provide transport functions in the body.
D. Sterols
1. Characteristics
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a. Their structure and function is quite different from both triglycerides
and phospholipids.
b. The most commonly known sterol is cholesterol.
c. Sterols are hydrophobic and lipophilic.
2. Structure
a. Unlike other lipids, most sterols do not contain fatty acid chains.
b. Sterol molecules consist of multiple rings made primarily of carbon and
hydrogen atoms that are attached to each other.
3. Cholesterol is a sterol consisting of a hydrocarbon with a multiple-ring
structure (see Figure 4.7).
a. Although much maligned because of its relationship to heart disease,
cholesterol serves some critical roles in the body (p. 107).
b. Cholesterol is produced in the liver, small intestine, and walls of arteries
daily; therefore, it is not considered an essential nutrient.
c. It is found only in animals and humans.
4. Plant sterols and plant stanols
a. They are found only in plants.
b. Both have cholesterol-lowering effects in the body.
Author Note: Students can research products on the market that contain plant sterols and plant
stanols. Discuss the pros and cons of these products, such as cost, convenience, effectiveness,
and other options for substitutions for saturated or trans fats.
E. Artificial fats (fat substitutes)
1. Fat substitutes are popular in a variety of foods, including "luxury" foods such
as ice cream, salad dressings, and desserts.
2. The goal of fat substitutes is to decrease calories while maintaining the texture
and taste of foods.
3. Fat substitutes can be made from carbohydrates, proteins, or fats.
a. Carbohydrate-based fat substitutes are made from starches, fibers, and
gums. They contribute only 4 calories per gram (versus 9 calories per
gram in fat).
b. Whey protein from dairy or egg whites is used to produce protein-based
fat substitutes. Simplesse is an example.
c. Engineered fats manipulate the degree of saturation and fatty acid chain
length to produce similar qualities in food products as fats and oils.
Olestra, trade name Olean, is an engineered combination of sucrose and
fat that is nondigestable, and therefore calorie free.
4. Table 4.3 provides examples of some of the more common fat substitutes found
in the U.S. food supply.
IV. How much fat is recommended in an athlete's diet?
A. Fat is an essential nutrient in the diet.
B. No RDA or AI is set for total fat intake, because there is insufficient data to determine
a defined level of fat intake at which risk of inadequacy or prevention of chronic disease
occurs.
C. The Acceptable Macronutrient Distribution Range (AMDR) for fat intake has been set
at 20 to 35% of total energy for adults.
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D. The American Heart Association promotes a slightly stricter range, recommending a
total fat intake of 30% or less of total energy intake in order to decrease cardiovascular
disease risk.
E. The National Cholesterol Education Program (NCEP) recommendations are as
follows:
1. 30% or less of total calories from fat, with 10% of calories coming from
polyunsaturated, 10% from monounsaturated, and a range of 7 to 10% from
saturated fat (less than 7% for individuals with high cholesterol).
2. These guidelines may not be appropriate for athletes unless they have higherthan-recommended cholesterol and LDL cholesterol levels.
F. In general, athletes report an average fat intake of 35% of total calories; however, fat
intake varies among athletes in different sports.
1. Endurance athletes tend to have lower fat and higher carbohydrate intake than
sprinters and short-distance runners.
2. Athletes dieting for weight loss and those involved in sports requiring weighins or judging on appearance also tend to have lower fat intake.
3. Collegiate athletes, many of whom are living away from home, may consume
too much dietary fat due to an over-reliance on fast foods.
a. Over-consumption of fats usually leads to ingesting too many calories.
b. Excessive calories can lead to increases in body fat levels; in most
cases, this has detrimental effects on sport performance.
G. Athletes should focus not only on the total amount of fat in their diet, but also on the
type of fat consumed.
1. Saturated and trans fats should be kept to a minimum. These fats have been
shown to be the most detrimental to cardiovascular health because they increase
cholesterol levels.
2. Monounsaturated and polyunsaturated fats are beneficial to health, leading to
more favorable cholesterol levels and possibly aiding in the prevention of cancer
and arthritis.
H. A diet can be too low in fat.
1. Because dietary fat contributes a significant amount of calories per gram, low
fat intake can negatively affect energy balance.
2. Deficiency in essential fatty acids can result from severe restriction of dietary
fat intake.
I. A diet can be too high in fat. Consuming too much fat can lead to the consumption of
too many total calories, resulting in weight gain in the form of body fat.
Author Note: Students should practice calculating total fat, saturated fat, and unsaturated fat
requirements based on various calorie levels (e.g., 2,000, 2,500, and 3,000 calories).
V. Which foods contain fat?
A. Fats are found within most food groups of the MyPyramid food guidance system;
however, the richest sources of fat are found within the oils category (Table 4.2).
B. Fat in the grains group
1. Whole grains, such as oatmeal, barley, bulgur wheat, millet, and spelt, contain
less than 1 to 3 grams of fat per serving. The fat in these grains is mainly
unsaturated.
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2. Foods such as biscuits and croissants are high in fat, with a larger percentage
coming from saturated and trans fats.
3. Training Table 4.1 provides some tips on including low-fat grains in meals.
C. Fats in the fruit and vegetable groups
1. In general, fruits and vegetables contain minimal to no fat.
2. Certain vegetables, such as avocados and olives, contain a considerable amount
of fat, although it is mainly unsaturated.
3. Training Table 4.2 provides some tips on using fruits and vegetables rich in
unsaturated fats.
D. Fats in the milk/alternatives group
1. Full-fat dairy products, such as whole milk or hard cheeses, may contain 8 to
10 grams of fat per serving, with a high percentage coming from saturated fat.
2. Low-fat or nonfat dairy products, such as skim milk, low-fat yogurt, and
cottage cheese, may have only 1 to 4 grams of fat or less per serving.
3. Most soy, rice, or other dairy-alternative products contain approximately 1 to 6
grams of fat per serving. The fats in dairy alternatives are mainly unsaturated fats,
and therefore excellent substitutes for full-fat dairy products.
4. If fortified, low-fat and nonfat dairy products, as well as dairy-alternative
products, contain the equivalent amounts of calcium and vitamin D as their fullfat counterparts.
5. Training Table 4.3 provides tips on including low-fat milk/alternative products
in meal planning.
E. Fats in the meat and beans/alternatives group
1. In general, beef contains a higher quantity of fat and a higher percentage of
saturated fat than most other foods in this group.
2. Chicken, turkey, and pork contain moderate amounts of total fat and saturated
fat.
3. Some fish are very lean, such as orange roughy, whereas others are higher in
fat, such as salmon. However, a majority of the fat in fish is unsaturated.
Additionally, the fats from some fish are a rich source of omega-3 fatty acids.
4. Eggs, especially egg whites, are relatively low in fat.
5. Nuts and seeds contain higher levels of fat, but similar to fish, they contain
mainly unsaturated fats.
6. Legumes are very low in fat and the little they do contain is unsaturated.
7. Soy products range from low-fat choices, such as tofu, to higher fat choices,
such as soy nuts, but they also consist mainly of unsaturated fats.
8. Training Table 4.4 provides meal-planning tips for using low-fat meat and
beans/alternative products.
F. Fat in the oils group
1. The best choices within this group are unsaturated oils, such as olive, canola,
flax, and sesame oils.
2. Saturated and trans fatty acids, which are found in butter, margarine, snack
items, desserts, and other fried or processed foods, should be kept to a minimum.
3. Training Table 4.5 provides some healthier options within the oils group.
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Author Note: Students can partner up and interview each other regarding their favorite foods.
Have students examine the fat content of these foods and, based on their findings, develop 2 to 3
days of meal plans for their partner that include low or healthier fat alternatives.
VI. How can the percentage of calories from fat be calculated for specific foods?
A. All athletes should be aware of how to calculate the percentage of calories from fat in
various foods in order to make healthy food choices (see Figure 4.8).
B. The percentage of total calories from fat, saturated fat, or trans fat for any food item
can be calculated by the following basic formula:
<calc>% calories from fat = {calories from fat / total calories} × 100</calc>
1. In order to complete the equation, an athlete will need to do some fact finding
on the food label and know how to calculate the calories from total, saturated, or
trans fat listings.
2. The total calories per serving and total calories from fat are listed at the top of
the Nutrition Facts label on any food product.
C. If the calculated percentage is less than 35%, the athlete knows the product fits within
healthy eating guidelines.
1. Athletes should keep in mind that the recommendation for 20 to 35% of total
calories coming from fat is a guideline for the overall diet—not necessarily for
every individual food eaten in the diet.
2. Sometimes athletes will take this recommendation too far and unnecessarily
exclude all foods that do not fall into this category.
3. Athletes should use the percentage of calories from fat, along with other
nutritional benefits or drawbacks, to fully evaluate a food or beverage in the
context of an entire meal.
D. If the athlete is trying to determine the percentage of calories from saturated fat, trans
fat or obtaining nutrition information about a product from sources other than the food
label, the information needed is:
1. Total calories per serving
2. Total grams of fat, saturated fat, or trans fat per serving
a. One extra step is required before the numbers can be plugged into the
equation listed earlier.
b. Multiply the number of grams of fat, saturated fat, or trans fat by 9
(because there are 9 calories per gram of any type of fat) to obtain the
number of calories from fat.
E. If the percentage of saturated fat, as well as monounsaturated and polyunsaturated fats,
is approximately 7 to 10%, the athlete will know the product fits within healthy eating
guidelines.
F. Trans fats should be kept to a minimum.
1. The FDA approved a regulation in 2003 that all food labels must list the
amount of trans fats contained in the products by January 2006.
2. Currently, there is not an RDA for trans fats and no specific recommendations
for the maximum number of grams of trans fat to consume daily.
G. Athletes need to be careful not to confuse the “% Daily Value” and "% fat free" as the
food product’s percentage of calories from fat.
1. The % Daily Value provides the relationship between eating one serving of a
product and how that compares to total daily calorie needs (Figure 4.9).
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2. The "% fat free" statements are based on the total weight of the food product,
not the total calorie content of the product.
VII. What's the big deal about cholesterol?
A. On the basis of ongoing research in the area of cardiovascular health, high blood
cholesterol has been strongly associated with a higher risk for cardiovascular disease.
1. Blood cholesterol levels have been targeted as one of the first lines of defense
in the prevention of cardiovascular disease.
2. One of the best ways to modify blood cholesterol levels is to adapt lifestyle
factors, such as exercise and diet, specifically dietary fat, saturated fat, and
cholesterol consumption.
B. Cholesterol is a sterol.
C. Cholesterol is found only in animal products (see Table 4.4).
1. All meats contain cholesterol; organ meats contain the highest amounts.
2. Eggs and dairy products also contain cholesterol; nonfat dairy options contain
the least.
3. Some breads, muffins, and baked goods will have cholesterol if they were made
with eggs and/or dairy products.
4. Plant products, such as fruits, vegetables, whole grains, legumes, and soy, are
cholesterol free.
a. These foods do contain plant sterols, however, which have a similar ring
structure to cholesterol.
b. Plant sterols or stanols have recently been investigated for their
potential as cholesterol-lowering substances.
D. Blood cholesterol classifications
1. Cholesterol is measured by taking a sample of blood and analyzing the levels of
total cholesterol, high-density lipoprotein (HDL), and low-density lipoprotein
(LDL).
2. Each component can provide unique information regarding an individual's risk
for heart disease.
3. Several other cholesterol components can be tested to contribute additional
information, such as triglycerides, very low-density lipoproteins (VLDLs), and
lipoprotein (a).
4. Refer to Table 4.5 for the National Cholesterol Education Program's
classification of lipoprotein levels.
5. Total cholesterol can provide a general estimate of risk, but is not as
informative as the breakdown of the various lipoproteins.
6. HDL is a "scavenger," picking up cholesterol from the bloodstream and arteries
and delivering it to the liver to be packaged into bile and excreted from the body.
HDL is considered protective, and thus is termed the "good cholesterol."
7. LDL is a cholesterol-rich lipoprotein that delivers cholesterol to the cells of the
body, where it will be used for a variety of functions. If arterial damage occurs,
LDL can build up, eventually escalating into atherosclerosis (Figure 4.10).
8. VLDL and lipoprotein (a) have also been associated with a higher risk for
cardiovascular disease; however, the NCEP has not established a guideline for
screening, prevention, or treatment of high VLDL or lipoprotein (a).
VIII. How can fats affect daily training and competitive performance?
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A. Fats are a major fuel source for muscle cells.
B. Fats are the primary source of energy at rest, during low- to moderate-intensity
activities (Figure 4.11), and during recovery periods between intense bouts of activity.
C. Endurance training improves the body's ability to utilize fats for energy.
1. The body's ability to mobilize fats from adipocytes is enhanced, thus making
more fatty acids available to the working muscle.
2. The working muscle's capacity to oxidize/utilize fats is improved due to:
a. Increased muscle blood flow.
b. Improved transport of fats into the muscle cells.
c. Larger and more numerous mitochondria.
d. Increased quantities of enzymes involved in fat metabolism.
D. However, fats are not the body’s fuel of choice at higher levels of exercise intensity.
1. Fats have a relatively slow rate of adenosine triphosphate (ATP) production
compared to carbohydrates.
2. Fat within the muscle does not provide much energy during exercise; therefore,
fats must be released from adipocytes and then delivered to the working muscles
via the blood, which is slow.
IX. What type, how much, and when should fats be consumed before exercise?
A. Researchers have examined the ability of fat to enhance performance when consumed
in the hours, days, or weeks before training or competition:
1. A single high-fat meal prior to exercise
a. Theory: A high-fat meal prior to competition will increase fatty acid
levels in the blood and in turn enhance endurance performance compared
to a high-carbohydrate meal.
b. The majority of studies have not found any benefit to ingesting high-fat
meals prior to competition when compared to high-carbohydrate meals.
c. Many athletes find that eating a meal high in fat 1 to 4 hours prior to an
exercise session, or especially a competition, leads to gastrointestinal
distress, including bloating, diarrhea, stomach cramping, and a sense of
fullness.
d. It is not recommended that athletes eat a high-fat meal immediately
prior to exercise due to the potential for gastric upset.
2. A short-term pattern of eating high-fat meals prior to exercise
a. "Short term" is defined as less than 2 weeks.
b. Theory: Consumption of a relatively high-fat diet in the 1 to 2 weeks
prior to exercise will cause the body to adjust to the higher fat intake and
become more efficient at using fat for fuel during exercise. This
adjustment by the body has been termed “fat adaptation.”
c. Research regarding short-term fat consumption and endurance
performance is equivocal.
d. At this time, short-term high-fat intake does not appear to be an
effective practice for improving athletic performance.
3. A long-term pattern of eating high-fat meals prior to exercise
a. "Long-term" is defined as greater than 2 weeks.
b. Overall, no benefit has been found over balanced, high-carbohydrate,
moderate-protein, low-to-moderate fat diets.
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c. High-fat diets can cause favorable shifts in fat metabolism; however,
they also lead to lower muscle-glycogen stores.
d. The improvement in fat utilization is not enough to offset the effect of
diminished glycogen stores.
e. At this time, long-term, high-fat dietary intake cannot be recommended
as a means to improve athletic performance.
B. Recommendations for fat intake prior to exercise
1. Athletes need to experiment with the best pre-exercise meal for their digestive
system and sport.
2. Fat will create a feeling of satiety, preventing an athlete from feeling hungry
before exercising.
3. Consuming too much fat 4 hours or less prior to exercise can cause bloating,
intestinal cramping, or diarrhea.
4. Meals and snacks within 4 hours of training sessions and/or competitions
should be low in fat and focused mainly on the unsaturated fats.
5. Refer to Training Table 4.7 for pre-exercise meals and snacks that contain a
small amount of fats and maintain a balance of carbohydrates and protein.
Author Note: Students should develop two to three different pre-exercise meals that contain
small amounts of unsaturated fats. Meals or snacks can be based on the fat preferences provided
during the partner activity mentioned earlier in this chapter.
X. What type, how much, and when should fats be consumed during exercise?
A. Long-chain triglycerides (LCTs)
1. Absorption of LCTs is slow.
2. Consuming high-fat foods during exercise is not beneficial, nor recommended.
B. Medium-chain triglycerides (MCTs)
1. They are absorbed readily and oxidized rapidly.
2. Early studies involved consuming small amounts (~30 grams) of MCTs before
exercise. These studies reported no effect on performance.
3. Approximately 45 to 85 grams of MCTs either before or during exercise has
been shown to cause a shift away from a reliance on carbohydrates, thus
improving time-trial performance.
a. However, ingestion of MCTs does not always produce these positive
results.
b. In many MCT studies, subjects complain of moderate to severe
gastrointestinal distress, which may hinder athletic performance.
4. At this time, a recommendation for athletes to consume MCTs during exercise
cannot be made.
XI. What type, how much, and when should fats be consumed after exercise?
A. It is not essential to replace fats used during exercise by consuming certain quantities
or types of fat immediately following training or competition.
B. The body's stores of fat are so great that they will not be depleted in an exercise
session, even after prolonged endurance events.
C. Fat intake should be kept to a minimum immediately after exercise.
D. Refer to Training Table 4.8 for some examples of postexercise meals that contain
small amounts of fat.
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