Chapter 5 Lipids: Fats, Phospholipids, and Sterols Slide 2
Copyright 2010, John Wiley & Sons, Inc. Lipids Lipid is the
chemical term for fat. Lipids contribute texture, taste, flavor and
aroma to foods. Fats and oils contain 9 calories per gram. The
typical American diet gets about 33% of its energy from fat. Slide
3 Copyright 2010, John Wiley & Sons, Inc. Visible and Hidden
Fat on the Menu Slide 4 Copyright 2010, John Wiley & Sons, Inc.
Types of Dietary Fat: Triglycerides Triglycerides are the major
form of lipid in food and in the body. Triglycerides consist of
three fatty acids attached to a glycerol molecule. If only one
fatty acid is attached to the glycerol it is called a
monoglyceride. Slide 5 Copyright 2010, John Wiley & Sons, Inc.
Visualizing Triglycerides and Fatty Acids Slide 6 Copyright 2010,
John Wiley & Sons, Inc. Visualizing Triglycerides and Fatty
Acids Slide 7 Copyright 2010, John Wiley & Sons, Inc. Fatty
Acid Composition of Foods Slide 8 Copyright 2010, John Wiley &
Sons, Inc. Trans Fatty Acids Slide 9 Copyright 2010, John Wiley
& Sons, Inc. Trans Fatty Acids Trans fatty acids can be created
by hydrogenation. Hydrogenation causes some double bonds to become
saturated. Hydrogenated fats can be found in margarines, vegetable
shortening and shelf- stable baked goods. Trans fatty acids have
been shown to raise blood cholesterol levels and increase the risk
of heart disease. Slide 10 Copyright 2010, John Wiley & Sons,
Inc. Essential Fatty Acids Slide 11 Copyright 2010, John Wiley
& Sons, Inc. Phospholipids Slide 12 Copyright 2010, John Wiley
& Sons, Inc. Phospholipids Slide 13 Copyright 2010, John Wiley
& Sons, Inc. Phospholipids Slide 14 Copyright 2010, John Wiley
& Sons, Inc. Cholesterol Slide 15 Copyright 2010, John Wiley
& Sons, Inc. Lipid Digestion Slide 16 Copyright 2010, John
Wiley & Sons, Inc. Structure of Lipoprotein Slide 17 Copyright
2010, John Wiley & Sons, Inc. Lipoproteins in the Body
Lipoproteins are transport particles for water-insoluble lipids.
Lipoproteins are created by combining water-insoluble lipids,
phospholipids and proteins. Lipoproteins help transport
triglycerides, cholesterol and fat-soluble vitamins from the small
intestine and stored lipids from the liver. Slide 18 Copyright
2010, John Wiley & Sons, Inc. Transporting Lipids through the
Body Slide 19 Copyright 2010, John Wiley & Sons, Inc. Need for
Lipids in the Body Most lipids in the body are triglycerides stored
in adipose tissue. Deposits of adipose tissue help to define body
shape, provide stored energy, insulate the body from temperature
changes and protect internal organs against physical shock. Lipids
in the body are important for lubricated body surfaces, such as the
mucous membranes of the eyes. Slide 20 Copyright 2010, John Wiley
& Sons, Inc. Need for Lipids in the Body Cholesterol is used to
make several hormones, including estrogen and testosterone. PUFAs
help to regulate blood pressure and blood clotting. Essential fatty
acids are important for growth, skin integrity, fertility and the
structure and function of cell membranes. Slide 21 Copyright 2010,
John Wiley & Sons, Inc. Need for Lipids in the Body Eicosanoids
are made from omega-3 and omega-6 fatty acids. Eicosanoids help
regulate blood clotting, blood pressure and immune function. Fatty
acids and glycerol can be used to produce energy, in the form of
ATP. Slide 22 Copyright 2010, John Wiley & Sons, Inc. Lipids in
Health and Disease: Essential Fatty Acid Deficiency If adequate
amounts of essential fatty acids are not consumed, a deficiency can
result. Symptoms include: dry, scaly skin, liver abnormalities,
poor wound healing, growth failure in infants and impaired hearing
and vision. Slide 23 Copyright 2010, John Wiley & Sons, Inc.
Lipids and Cardiovascular Disease Over 70 million Americans suffer
from some form of cardiovascular disease. Studies show that diet
and lifestyle affect the risk of developing cardiovascular disease
Atherosclerosis is a disease in which lipids and fibrous materials
are deposited in artery walls. Slide 24 Copyright 2010, John Wiley
& Sons, Inc. Lipids and Cardiovascular Disease Slide 25
Copyright 2010, John Wiley & Sons, Inc. Whats Your Risk for
Heart Disease? Slide 26 Copyright 2010, John Wiley & Sons, Inc.
Food Pyramids and Heart Disease Slide 27 Copyright 2010, John Wiley
& Sons, Inc. Food Pyramids and Heart Disease Slide 28 Copyright
2010, John Wiley & Sons, Inc. MyPyramid and Healthy Heart
Choices Slide 29 Copyright 2010, John Wiley & Sons, Inc. Lipids
on the Menu Slide 30 Copyright 2010, John Wiley & Sons, Inc.
Lipids on the Menu Slide 31 Copyright 2010, John Wiley & Sons,
Inc. Reducing Heart Disease on the Menu Dietary factors that may
help to reduce the risk of heart disease include: Consuming omega-3
and omega-6 polyunsaturated fats Consuming monounsaturated fats
Consuming plant foods, including fruits, vegetables, whole grains
and legumes Adequate intake of B vitamins Moderate alcohol
consumption Slide 32 Copyright 2010, John Wiley & Sons, Inc.
Reduced-Fat Foods and Fat Replacers Reduced-fat foods either have
fat removed, have fat replaced or contain fats that cannot be
digested or absorbed. Fat substitutes can be carbohydrate-,
protein- or fat-based. Fat-based fat substitutes, such as Olestra
(sucrose polyester) can reduce the absorption of fat-soluble
vitamins. Slide 33 Copyright 2010, John Wiley & Sons, Inc. What
Should I Eat? Fats and Cholesterol Limit your intake of
cholesterol, trans fat, and saturated fat Use low-fat dairy
products. Trim the fat from your meat and serve chicken and fish
but dont eat the skin. Cut in half your usual amount of butter and
use soft rather than stick margarine. Use beans instead of meat in
your chili, soups, and casseroles. Increase the proportion of
polyunsaturated and monounsaturated fats Use olive, peanut, or
canola oil for cooking and salad dressing. Use corn, sunflower, or
safflower oil for baking. Snack on nuts and seeds. Add olives and
avocados to your salads. Up your omega-3 intake Bake flaxseeds into
breads and sprinkle them on your cereal or yogurt. Add another
serving of fatty fish, such as mackerel, lake trout, herring,
sardines, tuna, or salmon, to your weekly menu. Have a leafy green
vegetable with dinner. Add walnuts to your salad or cereal. Slide
34 Copyright 2010, John Wiley & Sons, Inc. End of Chapter 5
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