1 / 16

Chapter Three: Lipids

Chapter Three: Lipids. 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

mikaia
Download Presentation

Chapter Three: Lipids

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter Three: Lipids • 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

  2. Lipids contd. • 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

  3. What do you already know? • Lipids (fats) in review • Energy provided: 9 kcals. per gram • No more than 30% of kcals. per day • Sources in the Food Guide Pyramid • Milk, yogurt and cheese group • Meat and meat alternates group • Fats, oils and sweets group

  4. Nutritional Role of Lipids • Main function is for fuel or energy • Supplies about 60% of energy needs • Unlimited storage • Other roles of fats • Nourishment for hair and skin • Insulates and cushions organs & breasts • Major material of cell membranes • Most concentrated form of energy

  5. Forms of Lipids • Triglycerides: Fat storage in the body • 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 • Found in the cell membrane • Not essential—supplement not necessary

  6. Forms of Lipids contd. • 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

  7. Triglycerides

  8. Fatty Acids and Their Saturation Levels • 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

  9. Dietary Fats

  10. Fatty Acids cntd. • 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

  11. Fatty Acids cntd. • Polyunsaturated fats: No more than 10% (PUFAs) • 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

  12. Fat Substitutes • Carbohydrate based: Oatrim & Z-Trim • Stable when heated • Provides fiber and reduces kcals by ½ • Protein based: Simplesse • Found in dairy products and dressings • Not stable when heated • Reduced kcals. By 80%

  13. Fat Substitutes contd. • Fat-based: Olestra • Indigestible • Stable when heated and tastes like fat • Can cause digestive problems and nutrient losses

  14. Cutting Fat Intake & Choosing Unsaturated Fat Sources • 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

  15. Test Questions • 1. Which of the following fats is the stored fat in the body and available for energy. • A. Cholesterol • B. Phospholipids • C. Triglycerides • D. Lecithin

  16. Test Questions • 2. The term “unsaturated fat” means that: • 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

More Related