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Fats and Oils

Fats and Oils

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Fats and Oils

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  1. Fats and Oils Chapter 4

  2. Learning Objectives • List the role/function of fats/oils in the body • Describe digestion and how the body uses fats/oils • Distinguish between saturated, monounsaturated, polyunsaturated and trans fats • List the food sources of various types of fat • Discuss the recommended daily intake for saturated, monounsaturated, polyunsaturated and trans fats • State the current Dietary Guidelines for Americans that relate to fat intake • Evaluate and make recommendations for achieving balanced and healthy intakes of fat in the diet.

  3. Learning Objectives • Explain the functions of fats in food preparation. • Discuss ways to achieve a healthy balance of fats in recipe modification while maintaining texture and flavor • Compare different kinds of oils and fats • Describe the function, recommendations and food sources of dietary cholesterol • State the relationship of dietary fat to heart disease and obesity • Describe cholesterol, cholesterol intake to heart disease, food sources.

  4. How the Body Uses Fats • Most concentrated source of energy • 9 calories per gram of fat • 5 grams, 45 calories per teaspoon of fat/oil • 15 grams,135 calories per tablespoon of fat/oil

  5. How the Body Uses Fats • Primary stored energy is body fat • Carry fat soluble vitamins (A, D, E, K) • Component of cell membranes • Helps in production of hormones and Vitamin D • Body fat protects internal organs and insulates the body against temperature extremes

  6. Science of Fat • Lipids include fats, oils, cholesterol, lecithin and other compounds • Generally: • Fats – solid • Oils – liquid • Cholesterol- a sterol • Lecithin – a phospholipid emulsifier

  7. Cholesterol • Essential to life • Functions: • Cell membranes • Nerve fibers • Necessary to make hormones • For bile to digest food • Transforms to vitamin D with sunlight

  8. Cholesterol in the Body • HDL = high density lipoprotein • Good cholesterol • Picks up cholesterol and returns it to the liver • Too much polyunsaturated fats decrease HDL • LDL = low density lipoprotein • Bad cholesterol • Deposits fats in artery walls, creates plaque causing atherosclerosis • Increased by saturated fats and trans fats in the diet

  9. Optimal Serum Cholesterol

  10. Cholesterol Sources Made in the body (endogenous) Amount made influenced by genetics and the fat we eat Total fat, saturated fat, trans fat increase production of cholesterol

  11. Cholesterol Sources From diet (exogenous) Dietary cholesterol < 300 mg/day Dietary cholesterol < 200 mg/day if high risk for heart disease Only from animal foods One egg yolk/day does not raise blood cholesterol level or increase risk for heart disease No cholesterol in egg white.

  12. Foods High in Cholesterol

  13. Structure of Fat • Fats in foods usually triglycerides • 3 fatty acids joined to glycerol molecule • Fatty acids differ in size (chain length) and saturation

  14. Fatty Acid StructuresSaturation and Omega

  15. Comparing Fats/Oils • All fat/oils combine all three types of fatty acids • Fats are “called” one type • Example: • Canola oil is considered a monounsaturated fat • 62% monounsaturated, 32% polyunsaturated, 6% saturated • Butter is considered a saturated fat • 56% saturated, 29% monounsaturated, 2% polyunsaturated • See chart, page 71 of text

  16. Saturated Fats Solid at room temperature Primarily animal fats Butter, beef, pork, poultry, duck, lard, milk fat Tropical oils coconut, palm kernel and palm oil Tend to increase blood cholesterol, particularly LDL Increase risk of heart disease

  17. Monounsaturated Fats Generally healthiest Plant fats/oils Canola Olive Peanut, peanuts, peanut butter Avocado Almond, hazelnut, pistachio Grapeseed Do not increase total cholesterol levels or lower HDL cholesterol Substitute monounsaturated fats for saturated fats Careful to not ADD additional fat

  18. Polyunsaturated Fats Plant oils: Soybean Corn Sunflower Sesame (~ half mono/poly) Safflower Cottonseed Walnuts Fish and seafood Also for supplement but not for cooking Flaxseed Wheat germ Rice bran

  19. Trans Fats • Hydrogenation • Restructures molecular form of oils • Cis to trans bond • Stick margarine and shortening • Primarily in processed foods • Firm, creamy, stable • Snack and frozen, creamers, vegan • Small natural amount in beef, butter, milk

  20. Trans Fats • Most harmful form of fat for the heart • Raises LDL (bad) and lowers HDL (good) cholesterol • Read Label for trans fats: • “Trans-free” or “0 grams” • Means .49 grams trans fats or less • Listed as “hydrogenated” or “partially hydrogenated fat” on ingredient list

  21. Essential Fatty Acids • Needed by the body, body can’t make • All polyunsaturated • Keep cell walls flexible • Protect against cardiovascular disease and high blood pressure, promote healthy skin, immune function and aging

  22. Omega-3 Fatty Acids • Alpha-linolenic acids • Functions: • Reduce cardiovascular disease • Blood clotting • Promote eye health • Improve arthritis and autoimmune diseases

  23. Omega-3 Fatty Acids • Sources: • Fatty fish – 2 + servings weekly • Salmon, herring, mackerel, lake trout, sardines, anchovies, tuna • Grass-fed beef • Plants – walnuts, flax, canola, soybean, wheat germ • Some eggs, milk, margarine, cereals • Plant sources are not as well used as animal sources

  24. Omega-6 Fatty Acids • Linoleic acids • Functions: • Healthy cell membranes, skin, cells • Sources: • Oils • Safflower, grapeseed, walnut, corn oil, soy oil • Soybeans and tofu • Whole grains • Most Americans consume sufficient omega-6 fats in their diet

  25. Key Guidelines For Fat Intake

  26. Key Guidelines Cook with canola or olive oil Monounsaturated fatty acids Add or nibble on nuts and seeds Omega-3 polyunsaturated fatty acids Feast on fish and seafood Marine omega-3 PUFA But beware of mercury, eat a variety of fish and seafood

  27. Summary Recommended Intakes 20-35% of total calories from total fat About 44-78 grams (2000 calories) Up to 15% of total calories from monounsaturated 33 grams or less (2000 calories) Up to 10% of total calories from polyunsaturated 10% or less of total calories from saturated fat 22 grams (2000 calories) 7% of less to reduce the risk of cardiovasuclar disease The 2010 Dietary Guidelines for Americans, Institute of Medicine, American Heart Association, National Cholesterol Education Program

  28. Summary Recommended Intakes of Fat Trans fat 1-2% of calories or less from trans fats 5 grams or less Essential Fats Linoleic acid (AI) 12-17 grams Linolenic acid (AI) 1.1-1.6 grams

  29. Calculating % Calories From Fat 85 grams total fat, 1860 calories 85 x 9 calories/gram = 765 calories  1860 = 41% of total calories from fat 36 grams saturated fat, 1860 calories 36 x 9 calories/gram = 324 calories  1860 = 17% of total calories from saturated fat

  30. Calculating Fat Grams Calorie goal, % fat goal 1600 calories, 25% of calories from fat 1600 x .25 =400 calories  9 calories/gram = 44 grams a day

  31. Generally…What To Do…… Type of fats/oils Choose least saturated fats Increase monounsaturated Moderate poly Lower saturated Trans fat as low as possible Add omega 3 when you can Consider amount

  32. Simple Digestion of Fats

  33. Protein carrier of digested fats/oils, cholesterol Unused & trans to VLDL To fat stores EFA, unsaturated, sat fats to cells; unused trans & saturated to liver HDL picks up plaque, To liver for disposal. LDL taken up by cells LDL taken up by blood vessel

  34. Fats and Heart Health • High cholesterol and overweight risk factors for cardiovascular disease • Excess fat calories contribute to obesity • Saturated and trans fats increase blood LDL and cholesterol

  35. Functions of Fat in Foods • Texture: crispy, tender, flaky, chewy and creamy • Adds flavor • Adds aroma • Adds to eating pleasure • Feeling of fullness and eating satisfaction

  36. Fat Distribution in Diet

  37. Ingredient Guidelines- Proteins Moderate meat portions Trim visible fat Combine high and low fat meats Use meat fats for flavoring/combine with oils Use lean meats/cuts See protein chapter

  38. Animal Fat Composition

  39. Label Terms…. • Lean- Less than 10 grams fat, 4.5 grams saturated and trans combined per 100 grams • Extra Lean- Less than 5 grams fat, 2 grams saturated fat per 100 grams • Wild caught- not farm raised • Grass fed- not grain fed

  40. Healthy Meat Prep… • Dietary Guidelines- Lean or low fat meats • 80% lean vs 90% lean • Check ground meats…. • Top round, bottom round • “loin” • Cook using moist methods/grill/broil • Saute, poach, braise • Add flavor by…. • Using rubs • Marinades

  41. Other Protein Prep Ideas • Egg substitutes or egg whites • Substitute beans/legumes • Use meatless protein products • MyPlate balance to meal • Other ideas….

  42. Fats in Foods- Nuts • Nuts are high in fat and calories • Fat in nuts is heart-healthy • 1 oz beneficial • Most research is on walnuts and almonds • See chart on page 78

  43. Ingredient Guidelines- Added Fats Limit added fats to provide flavor and texture Small amount of flavorful coconut, bacon, pork Choose least saturated fats Use flavor infused oils Use reduced/low fat Sour cream Cheese sauces Cream sauces Substitute fruit purees, pureed beans

  44. Fats Used in Cooking - Seed and Nut Oil • Some are monounsaturated, some are polyunsaturated • Strong flavored oils have big flavor impact with a small amount used • Chinese peanut • Dark sesame • Macadamia • Hazelnut • Walnut oil • Flax and wheat germ oil • Very heat-sensitive • Fragile • Often used as food supplement or spa cooking

  45. Fats Used in Cooking - Vegetable Oil Spray Sprays reduce sticking to pans with few added calories Pump or aerosol sprays Still adds fat

  46. Fats Used in Cooking - Butter Unique taste and mouthfeel Unsalted preferred Whipped butter use as spread, not in cooking Butter preferred over stick margarine Blends

  47. Fats Used in Cooking - Margarine • Ingredients: oil, partially hydrogenated solid fats, milk solids, colors, flavors • Different degrees of saturation from hydrogenation • Soft tub- look for trans-free • Stick margarine • Stanol margarines -“heart healthy”

  48. Cooking with Fat Treat as limited resource Adjust flavors and textures when reducing fat Use fats where they contribute most to recipes

  49. Ingredient Guidelines- Dairy Use fat free, reduced fat milk and milk products Blend high fat dairy with low fat dairy Limit cheese Use part skim milk cheese Use less of highly flavored cheeses See chart on page 78