Dietary Fats Jennifer Hillan, MSH, RD, LD/N Family, Youth, and Community Sciences University of Florida/IFAS

Definitions Fatty acids: chains of carbon atoms – the building blocks of triglycerides (dietary fats) Triglyceride: compound made up of a glycerol molecule and three fatty acids – the chemical name for fat found in food and stored in the body – a type of lipid Lipids: a group of fat-soluble compounds including triglycerides, phospholipids, and sterols Cholesterol: a type of sterol – not the same as fat (triglyceride)

Why is Dietary Fat Important? It’s an essential nutrient – our bodies can’t make two fatty acids (linoleic and linolenic), so they must come from food. It’s a rich source of energy (9 kcals/gram). It gives food flavor and texture. It provides satiety because it’s slowly digested.

What Does Fat do in the Body? It’s an energy reserve (triglycerides are stored in adipose tissue). It insulates the body and protects it’s organs. It transports and aids in the absorption of fat- soluble compounds important for good health. –Vitamins A, D, E, and K –Carotenoids (group of compounds found in plants)

Types of Fatty Acids (FA) Foods contain a mixture of fatty acids. FA are classified as either saturated, monounsaturated, or polyunsaturated based on their chemical structure. Foods containing mostly saturated FA tend to be solid at room temperature. Foods containing mostly monounsaturated and polyunsaturated FA tend to be liquid at room temperature.

What are Some Food Sources of Fatty Acids? Saturated – animal products (including butter and lard); coconut and palm oils Monounsaturated – olive, safflower, canola, and peanut oils; nuts Polyunsaturated – sunflower, corn, and soybean oils; fatty fish

Fat and Health Saturated fats raise blood cholesterol. Unsaturated fats do not raise blood cholesterol. All fats are a concentrated source of calories; risk of overweight or obesity if not eaten in moderation.

Trans Fatty Acids Formed during hydrogenation (the process of making oils solid at room temperature) –Hydrogenated oils have longer shelf life. –Trans fatty acids are often found in stick margarine, shortening, French fries, chips, crackers, cookies, and doughnuts. Raise blood cholesterol levels

Omega-3 Fatty Acids Polyunsaturated fatty acids including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA) Found in canola, soybean, olive oils; fatty fish (such as salmon and mackerel); flaxseed and flaxseed oil; many nuts and seeds

What are the Health Benefits of Omega-3 Fatty Acids? Studies show reduced risk of coronary heart disease and stroke. Omega-3 fatty acids have been shown to: –Lower blood cholesterol and triglycerides –Prevent abnormal heart rhythms, blood clots, and atherosclerosis (thickening and hardening of the arteries) They may be beneficial in treating rheumatoid arthritis and mild hypertension; preventing some types of cancer. Connor, 2000; Uauy and Valenzuela, 2000

What About Fish Oil Supplements? They appear to be safe, however, long-term safety has not been determined. Combination with other blood-thinning herbs or drugs such as aspirin or warfarin can cause abnormal bleeding. Talk with health care provider before using. It’s preferable to eat fatty fish 2 or 3 times per week.

Dietary Recommendations Limit total fat to  30% of daily calories. Limit saturated fat to  10% of daily calories. Substitute mono- and polyunsaturated fats (including omega-3 fatty acids) for saturated fats. Read ingredient labels for trans fat content – look for “hydrogenated” oils. Consult with health care provider if taking fish oil supplements.

Resources for Educators and Consumers...

UF/IFAS Publications FCS8128 – Nutrition for Health and Fitness: Fat in Your Diet FCS8128 – Nutrition for Health and Fitness: Fat in Your Diet FCS8608 – Cut the Fat, Not the Flavor (poster set) FCS8608 – Cut the Fat, Not the Flavor (poster set) FCS8688 – What do You Know About Fat? FCS8688 – What do You Know About Fat? FCS8720 – Take a Look at the Pyramid Tip FCS8720 – Take a Look at the Pyramid Tip

Int’l Food Information Council (IFIC) Publications Everything You Need to Know About the Functions of Fat in Foods Everything You Need to Know About the Functions of Fat in Foods Fish and Your Health Omega-3 Fatty Acids and Health Questions and Answers About Trans Fats Questions and Answers About Trans Fats Sorting Out the Facts About Fat

Other Resources American Heart Association: Eating for a Healthy Heart – an easy-to- read booklet from the FDA available in English and Spanish: