lipids and fats

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lipids and fats

  1. 1. Lipids and Fats
  2. 2. Facts Fats belong to a group of organic compounds called lipids. Greasy substances that are insoluble in water Each gram of fat contains 9 calories. .
  3. 3. Functions Provide energy Carry fat-soluble vitamins Supply essential fatty acids Protect and support organs and bones Insulate from cold Provide satiety after meals .
  4. 4. Food Sources Animal ◦ Fatty meats and fish ◦ Dairy products ◦ Whole milk ◦ Egg yolk .
  5. 5. Food Sources Plant ◦ Vegetable oils and margarine ◦ Nuts and olives ◦ Chocolate ◦ Avocados .
  6. 6. Visible and Invisible Fats Visible fats ◦ Fats in foods that are purchased and used as fats, such as butter or margarine, lard, cooking oils Invisible fats ◦ Fats that are not immediately noticeable such as those in egg yolk, cheese, cream, and salad dressings
  7. 7. Fatty Acid Classification May be classified by the body’s need for them: ◦ Essential fatty acids (EFAs) ◦ Nonessential .
  8. 8. Fatty Acid Classification May be classified by degree of saturation with hydrogen atoms: ◦ Saturated ◦ Unsaturated  Monounsaturated  Polyunsaturated
  9. 9. Essential Fatty Acids Cannot be synthesized by the body and must be obtained from the diet Two families: 1. Omega-3 2. Omega-6 .
  10. 10. Nonessential Fatty Acids Can be synthesized by the body .
  11. 11. Saturated Fats Usually solid at room temperature In general, animal foods contain more saturated fatty acids than unsaturated Examples: meat, poultry, egg yolks, whole milk, whole milk cheeses, cream, ice cream, butter, chocolate, coconut, palm oil
  12. 12. Monounsaturated Fats Have one place among the carbon atoms where there are fewer hydrogen atoms attached then in saturated fats. Lower low-density lipoprotein (LDL or “bad” cholesterol) when they replace saturated fat in one’s diet Examples: olive oil, canola oil, avocados, cashew nuts Recommended: 15% of total daily calories
  13. 13. Polyunsaturated Fats Have two or more places among the carbon atoms where there are fewer hydrogen atoms attached then in saturated fats. Examples: cooking oils made from sunflower, safflower, sesame seeds, or from corn or soybeans; soft margarines whose major ingredient is liquid vegetable oil; and fish .
  14. 14. Polyunsaturated Fats Foods containing high proportions of polyunsaturated fats are usually soft or oily Omega-3 fatty acids (found in fish) lower the risk of heart disease. Omega-6 fatty acids have a cholesterollowering effect. Recommended: 8% or less of total daily calories
  15. 15. Trans-Fatty Acids (TFAs) Produced when hydrogen atoms are added to monounsaturated or polyunsaturated fats to produce a semi-solid product such as margarine or shortening TFAs raise low-density lipoproteins (LDL) and total cholesterol. Major source: baked goods and restaurant foods .
  16. 16. Hydrogenated Fats Polyunsaturated vegetable oils to which hydrogen has been added commercially to make them solid at room temperature This process, called hydrogenation, turns polyunsaturated vegetable oils into saturated fats. Margarine and shortening are made in this way. .
  17. 17. Cholesterol Cholesterol is a sterol, a fatlike substance. Exists in animal foods and body cells Does not exist in plant foods Essential for the synthesis of bile, sex hormones, cortisone, and vitamin D Needed by every cell in the body .
  18. 18. • Your client has been diagnosed with a high cholesterol level greater than 200 mg/dL. Answer the following questions:  What risks are associated with a high cholesterol level?  What can be done to lower a high cholesterol level? 5-22 Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 5-18 Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.
  19. 19. • 5-23 High cholesterol leads to atherosclerosis, a cardiovascular disease in which plaque (fatty deposits containing cholesterol and other substances) forms on the inside of artery walls. This can lead to heart attacks and strokes. Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 5-19 Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.
  20. 20. Reduce the amount of total fat, saturated fats, and cholesterol. • Increase monounsaturated fats in the diet, lose weight, and exercise. • Increase consumption of soluble dietary fiber. • Medication may be prescribed in some cases. Daily cholesterol intake should not exceed 300 mg. • 5-24 Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved. 5-20 Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.
  21. 21. Lipoproteins In the initial stages of fat absorption, bile joins with the products of fat digestion to carry fat. Later, protein combines with the final products of fat digestion to form special carriers called lipoproteins. Lipoproteins carry the fat in the blood to the body cells.
  22. 22. Lipoproteins Classified according to mobility and density Types ◦ Chylomicrons ◦ Very-low-density lipoproteins (VLDLs) ◦ Low-density lipoproteins (LDLs) ◦ High-density lipoproteins (HDLs)
  23. 23. Low-Density Lipoproteins (LDLs) Composed of 45% cholesterol with few triglycerides Carry most of the blood cholesterol from the liver to the cells Elevated blood levels greater than 130 mg/dL of LDL are thought to be contributing factors in atherosclerosis. “Bad” cholesterol
  24. 24. High-Density Lipoproteins (HDLs) Carry cholesterol from the cells to the liver for eventual excretion Levels of HDL greater than 35 mg/dL are thought to reduce the risk of heart disease Exercise, maintaining a desirable weight, and giving up smoking are all ways to increase one’s HDL “Good” cholesterol
  25. 25. Fat Alternatives Olestra ◦ ◦ ◦ ◦ ◦ Made from carbohydrates and fat FDA approved for use in snack food Government requires that food labels indicate olestra “inhibits absorption of some vitamins and other nutrients” Should be used in moderation Contains no calories; can cause cramps and diarrhea
  26. 26. (continued) Fat Alternatives Simplesse ◦ Made from egg white or milk protein ◦ Can be used only in cold foods Oatrim ◦ Carbohydrate-based; derived from oat fiber ◦ Can be used in baking but not frying
  27. 27. Dietary Requirements Deficiency symptoms occur when fats provide < 10% of total daily calories The Food and Nutrition Board’s Committee on Diet and Health recommends that people reduce their fat intake to 30% of total calories.
  28. 28. (continued) Dietary Requirements American Heart Association’s newest recommendation is to consume ≤ 7% of saturated fats, 8% polyunsaturated fats, and 15% monounsaturated fats. At present, 36% of calories in U.S. diets is derived from fats.
  29. 29. Chef’s Tips Most fish is lower in fat, saturated fat. And cholesterol than are meat and poultry Chicken is twice as fatty as turkey White meat with skin and dark meat are higher in fat If buying ground chicken, make sure that it is made only from skinless breast for the least amount of fat
  30. 30. Chef’s Tips Trimmed veal is leaner than skinless chicken When choosing beef, you will get the least fat from eye of round, followed by top round and bottom round Cooking techniques to reduce fat include roasting, grilling, broiling, sauteing, poaching, and braising
  31. 31. Steps in Cooking with Less Fat 1. 2. 3. 4. 5. 6. 7. Choose a lean cut (fish, chicken breast, trimmed meat) Order a quality product Trim the meat of visible fat Use flavorful rubs and marinades to allow new and creative options (rubs combine dry ground spices such as cinnamon, and finely cut herbs, such as cilantro) Choose a cooking method that will produce a flavorful, moist product, and that adds little or no fat to the food Flavor the dish Make the plate attractive
  32. 32. Conclusion Fats provide energy, carry essential fatty acids and fat-soluble vitamins, protect organs and bones, insulate from cold, and provide satiety after meals. Composed of carbon, hydrogen, and oxygen and are found in both animal and plant foods
  33. 33. Conclusion Each gram of fats provides 9 calories. Digestion occurs primarily in small intestines. An excess of fat in the diet can result in obesity and possible heart disease or cancer.
  34. 34. Prepared by : Jamaldin, Kayzel Pearl

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