Download NORMAL NUTRITION NURP 102 ANDERSON

Chapter Three: Lipids
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Identify the major roles of body fat
Identify the 3 classes of body lipids
Identify the chemical structure of
triglycerides and three ways fatty acids
differ from one another
Identify food sources of fats, how they
differ in saturation, and the dietary
recommendations of each type of fat
Lipids contd.
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Identify the roles of phospholipids and
sterols
Identify the current daily dietary
recommendations for fat intake
Identify artificial sources of fat
Explain what a trans-fatty acid is and
where it is found
What do you already know?
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Lipids (fats) in review
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Energy provided: 9 kcals. per gram
No more than 30% of kcals. per day
Sources in the Food Guide Pyramid
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Milk, yogurt and cheese group
Meat and meat alternates group
Fats, oils and sweets group
Nutritional Role of Lipids
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Main function is for fuel or energy
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Other roles of fats
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Supplies about 60% of energy needs
Unlimited storage
Nourishment for hair and skin
Insulates and cushions organs & breasts
Major material of cell membranes
Most concentrated form of energy
Forms of Lipids
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Triglycerides: Fat storage in the body
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Make up of three fatty acids attached to a
backbone of glycerol
Makes up 95% of fat in the body and in
the diet
Phospholipids: portion of other 5% of
lipids found in the body
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Found in the cell membrane
Not essential—supplement not necessary
Forms of Lipids contd.
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Sterols: portion of other 5% of
lipids found in the body
Forms are cholesterol, Vitamin D,
and sex hormones
 Cholesterol is found in cells and
used in metabolism—rec. level is
below 200 mg/dl in the blood
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Triglycerides
Fatty Acids and Their Saturation
Levels
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Saturated fats: No more than 10%
Contain all the hydrogen they can
hold
 Examples are animals fats, palm and
coconut oil
 Hard at room temperature
 Known to increase cholesterol levels
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Dietary Fats
Fatty Acids cntd.
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Monounsaturated Fats: 10%
One point of saturation is missing
 Examples are plant foods such as
nuts, avocados, and olive oil
 Softer at room temperature
 Have a neutral effect on cholesterol
levels
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Fatty Acids cntd.
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Polyunsaturated fats: No more than
10% (PUFAs)
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Missing multiple points of saturation
Examples are vegetables oils
Liquid at room temperature
Known to lower cholesterol levels
Sources spoil more easily at room
temperature
Fat Substitutes
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Carbohydrate based: Oatrim & Z-Trim
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Stable when heated
Provides fiber and reduces kcals by ½
Protein based: Simplesse
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Found in dairy products and dressings
Not stable when heated
Reduced kcals. By 80%
Fat Substitutes contd.
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Fat-based: Olestra
Indigestible
 Stable when heated and tastes
like fat
 Can cause digestive problems
and nutrient losses
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Cutting Fat Intake & Choosing
Unsaturated Fat Sources
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Choose low fat sources
Choose low fat cooking methods
Avoid hydrogenated fats
Avoid fast foods—chips, baked goods
and commercially-prepared foods
Trans-fatty acids: formed from the
hydrogenation of PUFAs
Test Questions
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1. Which of the following fats is the
stored fat in the body and available for
energy.
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A.
B.
C.
D.
Cholesterol
Phospholipids
Triglycerides
Lecithin
Test Questions
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2. The term “unsaturated fat” means
that:
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A. The fat lacks glycerol
B. Hydrogen ions are missing in the fatty
acid chains
C. The carbon chains in the fat are less
than ten
D. The fat is hard or solid at room
termperature