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Fats

Fats. Functions of Fats in the Body. Protect vital organs Digestion -fat in food is digested and absorbed into adipose, or fatty, tissue Energy provider and reserve- helps the body maintain a constant temperature Production and regulation of steroid hormones

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Fats

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  1. Fats

  2. Functions of Fats in the Body • Protect vital organs • Digestion-fat in food is digested and absorbed into adipose, or fatty, tissue • Energy provider and reserve- helps the body maintain a constant temperature • Production and regulation of steroid hormones • Maintaining nerve impulse transmission-myelin sheath • Major component of cell membranes • Transport the fat-soluble vitamins A, D, E, and K

  3. Functions of Fats in Foods • Energy-9 kcal/gram • Essential nutrients • Flavor and satisfaction • Fat substitutes are not absorbed and therefore do not provide energy or essential nutrients but may provide flavor and satisfaction • Engineered fats • Simpless • Olestra • Carrageenan • Guar gum

  4. Classes of Fats • Lipids • Glycerides • Triglycerides • Fatty acids • Saturated • Monounsaturated • Polyunsaturated • Lipoproteins

  5. Lipids • Organic substance made from carbon, oxygen, and hydrogen • Hydrophobic-do not dissolve in water • General term for a group of compounds: -Oils, fats, waxes, and cholesterol

  6. Triglycerides • Basic unit of fat and are composed of three ("tri-") fatty acids individually bonded to three carbons of glycerol • Comes from the diet (meats and plant oils) and our liver • Found in the blood stream-blood fats • Lipids are primarily stored as triglycerides in adipocytes • Elevated levels linked to Coronary Artery Disease

  7. Fatty Acids • Saturated Fatty Acid: • Filled or “saturated” with hydrogen • Unsaturated Fatty Acid: • Not completely filled with hydrogen atoms; less heavy and dense: • Monounsaturated: • One unfilled spot • Polyunsaturated: • Two or more unfilled spots

  8. Saturated Fatty Acids • State of being filled; fat is harder and solid. It’s structure is filled with all the hydrogen atoms it can hold.

  9. Saturated Fats • Examples of saturated fats: • Butterfat, coconut oil, palm oil, palm kernel oil, animal fat (bacon, lard, egg yolk, dairy fat, fatty meat)

  10. Foods High in Monounsaturated Fatty Acids • Olive oil • Canola oil • Peanut oil • Sesame oil • Grapeseed oil • Avocados • Hazelnuts • Almonds • Cashews • Sesame seeds • Pumpkin seeds • Macadamia nuts

  11. Foods High in Polyunsaturated Fatty Acids • Safflower oil • Sunflower oil • Corn oil • Soybean oil • Cottonseed oil • Salmon • Mackerel • Herring • Trout • Walnuts • Sunflower seeds

  12. Most foods contain a combination of saturated, monounsaturated and polyunsaturated fats: • Corn Oil-59% polyunsaturated and 24% monounsaturated fatty acids • Olive Oil-74% monounsaturated and 8% polyunsaturated fatty acids • Peanut Oil- 46% monounsaturated and 32% polyunsaturated fatty acids • Butter-62% saturated fatty acids • Coconut Oil-86% saturated fatty acids

  13. Essential Fatty Acids • Polyunsaturated fatty acids • Linoleic (omega-6) • Alpha-linolenic (omega-3) • These fats MUST come from the foods we eat. We cannot produce these as we can the other types of fatty acids (saturated, monounsaturated and cholesterol) • 10% of a daily dietary intake needs to come from essential fatty acids

  14. Essential Fatty Acids • Functions: • Reduces inflammation • May prevent risk factors associated with chronic diseases such as heart disease, cancer, and arthritis • Aids in brain memory, performance, and behavioral function • Infants who do not get enough omega-3 fatty acids from their mothers during pregnancy are at risk for developing vision and nerve problems • Symptoms of omega-3 fatty acid deficiency may include fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation

  15. Linoleic (omega-6) Food Sources • Safflower oil (richest natural source) • Sunflower oil • Soybean oil • Cottonseed oil • Evening primrose oil • Borage oil • Meat, poultry, and eggs

  16. Alpha-linolenic (omega-3)Food Sources • Flaxseed oil (highest linolenic content of any food), flaxseeds, and flaxseed meal • Soybean oil, canola oil, and wheat germ oil • Hempseed oil and hempseeds • Walnuts, pumpkin seeds, brazil nuts, and sesame seeds • Vegetables: grape leaves, kale, spinach, mustard greens, turnip greens, arugula, brussel sprouts, asparagus, cabbage, artichokes, broccoli, squash, sweet peppers, avocados, okra, peas • Salmon, herring, mackerel, sardines, anchovies, albacore tuna, and caviar

  17. Lipoproteins • Combinations of triglycerides, cholesterol, and fat soluble vitamins, and proteins • Transport lipids and cholesterol in the blood • They vary in density according to the fat load they carry • Low Density Lipoproteins (LDL’s) • Carry cholesterol from the liver to cells of the body • High Density Lipoproteins (HDL’s) • Collect cholesterol from the body's tissues, and bring it back to the liver

  18. Cholesterol • Not a fat • A fat related compound • Soft waxy substance found in the bloodstream • Liver makes about 2 grams per day • No cholesterol in plant foods • Functions: • Production of testosterone and estrogen • Synthesis of Vitamin D • Formation of Bile-aids in fat digestion • Food sources: • Dairy, meat, liver, kidneys, and eggs • Limit intake to less than 300 mg daily

  19. Healthy Cooking Oils Bad Cooking Oils Vegetable shortening Hard margarine Butter Palm oil Palm kernel oil Coconut oil • Olive oil • Canola oil • Flax seed oil • Peanut oil • Safflower oil • Sunflower oil • Corn oil

  20. Hydrogenation • Process of forcing hydrogen atoms into the holes of unsaturated fatty acids • Turns liquid fat (oil) into solid fats-longer shelf life and creamier • Destroys essential fatty acids • This process creates a new fat called trans fatty acids-body cannot use this fat and is deposited into arterial walls • Heart disease risk • Trans fatty acids are found in margarine, shortening, commercial baked foods like cookies, crackers, muffins, and cereals • Trans fat is similar to saturated fat because it tends to increase LDL cholesterol levels, but dissimilar because it also lowers HDL cholesterol levels as well

  21. Digestion of Fats • The primary digestion action occurring in the mouth is mechanical. Foods are broken up into smaller particles through chewing and moistened for passage into the stomach • Little, if any, chemical fat digestion takes place in the stomach • Small Intestine • Fat digestion occurs here • Enzymes from the pancreas • Bile from the gallbladder • Fat emulsifier: breaks fat into smaller particles allowing enzymes to penetrate it • Absorption

  22. Dietary Fat Requirements • 20-35 percent of your daily calories • Less than 10% from saturated fat • Linoleic acid (omega-6): • 17 g/day for men • 12 g/day for women • Linolenic acid (omega-3): • 1.6 g/day for men • 1.1 g/day for women • Dietary cholesterol be limited to 300 mg/day • Trans Fat as low as possible • Fat contains 9 calories per gram

  23. Assignment • Refer to page 43 • Answer questions Critical Questions 1, 3, and 4

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