1. Chapter 4: Fats/Lipids

2. What Are Fats? Fats are one type of lipid. Lipids : diverse class of molecules that are insoluble in water Lipids (fats) do not dissolve in water.

3. What Are Fats? Three types of lipids are found in foods: 1.triglycerides 2.phospholipids 3.sterols contain fatty acids

4. Fatty Acids

5. Fatty Acid Saturation

6. Fatty Acids Saturated fatty acids (SFAs) have hydrogen atoms surrounding every carbon in the chain. Contain no double bonds Monounsaturated fatty acids (MUFAs) lack hydrogen atoms in only one region. Contain one double bond Polyunsaturated fatty acids (PUFAs) lack hydrogen atoms in multiple locations. Contain more than one double bond

7. Triglycerides Lower total amounts of hydrogen

8. Fatty Acids Saturated fatty acids can pack tightly together and are solid at room temperature. Animal fats, butter, cheese, and lard are high in saturated fatty acids.

9. Fatty Acids Unsaturated fatty acids: *Do not stack together well *Are liquid at room temperature *Are present in plant oils may be: monounsaturated – one double bond *olive, canola oils; cashews polyunsaturated – more than one double bond *corn and safflower oils *fish and flax oils

10. Fatty Acids

11. Essential Fatty Acids Body cannot make enough or at all Must get from diet Omega-6/linoleic acid Pro-inflammatory Omega-3/linolenic acid Anti-inflammatory EPA DHA

12. Essential Fatty Acids

13. Omega-6 Vegetable oils Omega-3 Soy/canola oils; walnuts; flax EPA/DHA Converted from linolenic acid Coldwater fish (wild salmon, trout, herring) Just 1-2% of total daily kcals

14. Trans Fatty Acids Hydrogenation of a plant oil Process of forcing hydrogen atoms into a double bond Makes oil more solid (why?) VS

15. Trans Fatty Acids How can you tell if a food has them? “Partially hydrogenated _____ oil” in ingredients Is required on nutrition facts panel, but tricky! Found in any foods made with hydrogenated oils: Fast foods & Baked goods Crackers & Margarines + Hydrogen Oil Trans Fats

16. Trans Fatty Acids Eat the least amount possible: are detrimental to health change the way our cell membranes function reduce the removal of LDLs (bad) from the blood

17. Triglycerides Triglycerides (TGs) are composed of: three fatty acid molecules Fatty acids are long chains of carbon atoms surrounded by hydrogen atoms. one glycerol molecule Glycerol is a three-carbon alcohol that is the backbone of a triglyceride. *Most of the fat we eat (95%) and most of the fat we store are TGs*

18. Triglycerides

19. Short Video Differences in fat

20. Lipids Three types of lipids are found in foods: 1.triglycerides ✓ 2.phospholipids 3.sterols

21. Phospholipids Phospholipids are: composed of a glycerol backbone, two fatty acids, and phosphate soluble in water a critical component of cell membranes & lipoproteins manufactured in our bodies so they are not required in our diet found in peanuts egg yolks, salad dressings (emulsifiers)

22. Phospholipids

23. Sterols Sterols : lipids containing multiple rings of carbon atoms are essential components of cell membranes and many hormones are manufactured in our bodies and therefore are not essential components of our diet include cholesterol *Only found in animal products/foods

24. Why Do We Need to Eat Fats? Energy Fats provide 9 kcal per gram Fat is very energy-dense. Much of the energy used during rest comes from fat. Fat is used for energy during exercise, especially after glycogen is depleted. Fat is also used for energy storage. In adipose tissue Supply essential fatty acids

25. Why Do We Need to Eat Fats? Fat-soluble vitamins Vitamins A, D, E, and K are soluble in fat; fat is required for their transport. Fats are essential to many body functions. Cell membrane structure/function Gate keepers/parking restrictions Protection of internal organs Insulation to retain body heat

26. Why Do We Need to Eat Fats? Fats provide flavor and texture to foods. Creamy ice cream, crispy French fries, sizzling steak Fats contribute to making us feel satiated because: fats are more energy-dense than carbohydrates or protein 9 kcals/g vs. 4 kcals/g fats take longer to digest More steps involved in digestion process

27. Fat Content of Foods Fats are in plant and animal foods Saturated: meats, butter, cheese, coconut oil Trans: processed, fast foods Polyunsaturated: Fish and veggie oils, nuts, seeds Monounsaturated: Olive and canola oils Only animal foods contain cholesterol

28. Fat Substitutes CHO-based 1-4 kcal/gram Protein-based 4 kcal/gram Fat-based 4-5 kcal/gram May cause gastrointestinal problems May impair absorption of A, D, E, K Beware of calories

29. Recommended Fat Intakes Recommended Intake Total fat (AMDR)20% - 35% of daily calories Saturated fat<10% of daily calories Trans fatAs low as possible Cholesterol<300 mg Polyunsaturated fat10% - 12% of daily calories Monounsaturated fat10% - 12 % of daily calories Table 4.3

30. Recommended Fat Intakes Children <2 years old 30% - 35% of daily calories from fat Supports rapid growth Especially brain and nervous system Athletes may need more energy from carbohydrates and can reduce their fat intake to 20– 30% of total calories.

31. Fat Intakes Visible Fat Invisible Fat

32. Questions What are ways you can limit total fat intakes? What are ways you can increase unsaturated fats and decrease saturated/trans fats? Does eating fat make you fat? All types of fat contain 9 kcal/gram

33. Transport of Fats Problem: fats hate water and the blood is watery Solution: fats are arranged as lipoproteins 4 types of lipoproteins

34. Types of Lipoproteins 1. Chylomicron : a lipoprotein produced by cells lining the small intestine Transport dietary fats to cells and liver 2.Very Low-Density Lipoproteins (VLDLs) Formed in the liver Take triglycerides to cells and tissues 3.Low-Density Lipoproteins (LDLs) Formed when VLDLs deposit triglycerides High concentration of cholesterol = take to cells/tissues 4.High-Density Lipoproteins (HDLs) Formed in the liver Remove cholesterol and transport it back to liver

35. Types of Lipoproteins

36. Composition of Lipoproteins SFAs, sugars, extra kcals N-3 FAs, exercise Circulate until absorbed! SFAs, trans fats “bad cholesterol” Decreases risk of CHD: “good cholesterol” N-3 FAs and exercise

37. Heart Disease #1 cause of death for men and women Type of fat in diet can contribute to or protect from Atherosclerosis is the primary type Can lead to heart attack or stroke

38. Heart Disease Diets high in saturated fats: decrease the removal of LDLs from the blood contribute to the formation of plaques that can block arteries increase triglyceride levels (chylomicrons and VLDLs) and total cholesterol

39. Heart Disease Trans fatty acids: can raise blood LDL levels as much as saturated fat are abundant in hydrogenated vegetable oils (margarine, vegetable oil spreads) As well as foods fried in such oils (French fries, doughnuts) should be reduced to the absolute minimum in the diet

40. Heart Disease Risk factors for cardiovascular disease include: being overweight physical inactivity smoking high blood pressure diabetes abnormal blood lipids © 2013 Pearson Education, Inc.

41. Heart Disease To reduce risk: Maintain fat intake between 20-35% PUFAs up to 10%, MUFAs up to 20% Decrease SFAs to 7%, cholesterol to <300 mg Eat more whole grains, fruits, veggies More fiber (especially soluble) = lower LDL Get blood lipids checked Be active Maintain healthy weight Avoid tobacco (1 st and 2 nd hand) © 2013 Pearson Education, Inc.