Fats: A Concentrated Energy Source Chapter 6: Nutrition, Food, and Fitness

Should We Be Concerned About Fats? There are some good reasons to be concerned about fat in your diet. Most of them are health-related. But not all fats are bad. In fact, fats perform many important functions in the body. You need to eat foods containing some fat every day. Your goal should be to choose foods with the right amount of fat for a healthful diet.

What Are Lipids? Lipid is a broader term for a group of compounds that includes fats & oils, lecithin and cholesterol. Triglycerides are the major types of fat/oil found in foods & in the body. They consist of 3 (tri) fatty acids attached to a glycerol molecule. The fatty acid molecules can be saturated or unsaturated.

Saturated Fats Saturated fats are saturated with hydrogen atoms. Generally solid at room temperature. Saturated fats from animals contain cholesterol.

Unsaturated Fats Unsaturated Fats have at least one double bond between two carbon atoms in each molecule. Can be polyunsaturated or monounsaturated Generally liquid at room temperature ~ oils Plant sources are higher in unsaturated fats, but nearly all fats & oils contain a mixture of the three types of fatty acids.

Trans-Fats Trans fats are unsaturated fats that have hydrogen added This process is called hydrogenation or partial hydrogenation. This is done to prevent oils from turning rancid (spoils & has unpleasant taste and smell) Saves businesses money & prolongs shelf life of product, but very unhealthy.

Cholesterol Cholesterol is a white, waxy lipid made by the body therefore not an essential nutrient. Part of every cell in your body it is used to make sex hormones & bile acids. Found only in animal tissue and all animal-origin foods. Not found in plants.

Functions of Fats (There are 6!) Fats and oils provide a concentrated source of energy; 9 calories per gram. Helps insulate your body ~ hold in heat. Cushions your vital organs. Acts like a shock absorber for your liver and other organs.

Functions of Lipids cont’d Carries & stores the fat-soluble vitamins A, D, E, & K. Part of the structure of every cell in your body. In food, fats affect the taste, texture, and aroma of foods. Fat is flavor!

Recommended Dietary Fat The 2015 USDA Dietary Guidelines for Americans recommend: Total Fat intake of no more than 20 to 35% of total calorie intake Saturated Fat intake not more than 10% of total fat For a 2000 calorie/day diet that means a total of 44-78 grams/day of fat each day.

What happens if I have too much fat in my diet? Too much fat can make you fat by adding calories to your diet! Obesity increases your risk for cardiovascular disease (CVD)…heart disease. Eating too much saturated fat may increase your cholesterol level, which can increase your risk of heart attack.

Heart Disease and You: Uncontrollable Risk Factors Age: most heart attacks occur after age 65 Gender: men are at greater risk than women Race: African-Americans are twice as likely to have a heart attack as members of some other races Family History: if one or more blood relatives had heart disease your risk increases

Heart Disease and You: 7 Controllable Risk Factors Smoking: is stupid Hypertension: high blood pressure High Blood Cholesterol: can be genetic; can often be controlled by diet Diabetes: causes blood vessels to become damaged or blocked with fat

Controllable Risk Factors cont’d Excess Weight: increases your chance of diabetes, high blood pressure, and high cholesterol Inactivity: you need to give your heart a workout to keep it healthy Stress & Personality: develop emotional balance & skills to deal w/stress. Set priorities, sleep well, enjoy a hobby

Limiting Fat & Cholesterol in Your Diet Be a Fat Detector: be aware of visible (fat on meat, butter on bread) and invisible fat (in snack foods, baked goods). Make Diet Changes: keep a food diary to analyze your eating habits ~ keep the good ones & change the bad ones. Eat lots of fresh fruits and vegetables. Set realistic goals for yourself; support from family & friends helps!

Too Little Fat in Your Diet… ….can lead to Trouble absorbing nutrients, such as the fat-soluble vitamins A, D, E, and K Poor hormone production Impaired growth & body health Lack of energy Dry, flaky skin