1. The Good, the Bad and the Truly Ugly!
Lipids
The Good, the Bad and the Truly Ugly!

2. Lipids Organic molecules most of which do not dissolve in water.
Fats & oils
Types of lipids:
Fatty acids
Glycerides
Phospholipids
sterols

3. Fatty Acids Carbon chains Methyl, acid groups Degree of saturation
Location of first double bond

4. Types of Fatty Acids

5. Glycerides
The major form of lipid in food and in the body

6. Phospholipid Lecithin, a common food additive, is a phospholipid.
Embedded in cell membranes.

7. Sterols Cholesterol: 90% is found in cell membranes
Produced by the liver
Associated with cardiovascular disease
Produced by animals only. None found in plants.

8. Fats in the Diet
Typically meats, dairy products, & other animal products are the main source of saturated fatty acids.
Palm, coconut oils are high in saturated fats.
Unsaturated fatty acids tend to come from plant oils: olive, canola, peanut , safflower, sunflower, corn; also fish, nuts

9. Fats in the Diet

10. Unsaturated Fats in the Diet
Omega-6-
Omeg-3-
The Good!

11. Hydrogenated Fats
Hydrogenation of vegetable oils converts some of unsaturated bonds to saturated, trans conformation.
Trans fatty acids extend shelf life, improve margarine, shortening.
Diet high in trans fatty acids risks heart disease, cancer.

12. Trans Fatty Acids
The Truly Awful!

13. Function of Lipids Immediate source of energy
Stored form of energy (85% triglycerides)
Protection and cushioning
Eye sockets, heart valves, kidneys, fatty apron
Insulation (temperature regulation)

14. Adipose Tissue
Fat stored in this cell

15. Fat Storage

16. Another view….

17. Fat Storage Area

18. When there is a bit much….
Abdominoplasty
Before
After

19. Function continued
Structural part of cell membranes (phospholipids, cholesterol)
Regulation
Cell communication, neurotransmitter synthesis
Bile salts (from cholesterol),
Hormones (from cholesterol)
Prostaglandins, eicosanoids (from omega-3 & omega-6 fatty acids)

20. Fat Packed on Heart

21. How you store fat….and then release it

22. Essential Fatty Acids Linoleic, alpha-linolenic acid are essential
Deficiency
Rare because requirement is low
Symptoms: scaly, dry skin, liver abnormalities, poor healing of wounds, growth failure, impaired vision and hearing
Observed in infants, young children fed low-fat diets, adults consuming a weight-loss diet of only nonfat milk

23. Reduced Fat Foods
Variety of reduced fat and free fat foods are available.
Designed to mimic taste, texture of fat
Low fat may mean low fiber, vit., minerals
Low fat foods are not always low in kcal
In many foods, fats are replaced with other energy-containing nutrients
Regular brownie has 112 kcal; reduced fat brownie has 89 kcal

24. Low Fat Diet
A diet low in fat & high in simple sugars increases blood triglyceride levels & may increase the risk of heart disease. May increase risk of diabetes.
May not be a healthy diet.
Snacks of fresh fruits instead of these would be much better.

25. Types of Artificial Fats
Carbohydrate-based fat substitutes
Pectins, gums mimic texture of fat
Oatrim, Nutrim add soluble fiber
Protein-based fat substitutes
Simplesse is fat substitute made from egg white, milk proteins
Used in frozen desserts, cheese foods; 1.3 cal/g
Poorly absorbed fats as fat substitutes
Caprenin consists of glcerol with 3 poorly absorbed fatty acids attached; 5kcal/g
Olestra has fatty acids attached to sucrose; cannot be digested; no absorption

26. The
Good!

27. The
Bad!

28. The
Truly
Awful!

29. The Consequences of Poor Choices!
The Ugly