Fats are organic compounds that consist of carbon, hydrogen and oxygen. The National Institutes of Health says fats are a source of energy in foods, and are a combination of saturated and unsaturated fatty acids. Consuming an excess fat, especially saturated fats and trans fats, can lead to unhealthy cholesterol levels, obesity and heart disease.
Function
The body needs fat to function properly. Fats supply essential fatty acids which help to control inflammation, blood clotting and brain development. Fat also helps to maintain healthy skin and hair and assists the body in absorbing vitamins A, D, E and K and moving them through the bloodstream.
Effects
Fat and cholesterol do not dissolve in water or blood. Therefore, the body encases fat and cholesterol into small, protein-coated fragments called lipoproteins. Although these particles can carry a substantial amount of fat, they are able to flow in the bloodstream. Lipoproteins include triglycerides, low density lipoproteins (LDL) and high density lipoproteins (HDL).
Unsaturated Fats
Monounsaturated and polyunsaturated fats have few negative effects on blood cholesterol levels. They are referred to as "good fats" because they can improve cholesterol levels and help keep heart rhythms stable. Examples of monounsaturated fats are vegetable oils, such as olive, canola, and peanut; avocados; and many nuts and seeds. Polyunsaturated fats include fish--salmon, herring, trout, sardines--sunflower, walnuts, corn and soybean oils. Keep in mind that unsaturated fats are high in calories and you should still eat them in moderation.
Saturated Fats
Saturated fats are the primary dietary cause of high LDL (bad) cholesterol and should be restricted to 10 percent of your daily calories. Saturated fat also raises HDL (good) cholesterol, as does all dietary fat. The Harvard School of Public Health says saturated fats include fatty meats, butter, cheese, palm, palm kernel and coconut oils.
Trans Fatty Acids
The American Heart Association recommends avoiding foods that contain trans fat and to help manage your cholesterol. Trans fats form when vegetable oil hardens--in a process called hydrogenation. Trans fats can raise LDL levels while simultaneously lowering HDL cholesterol. Examples of trans fatty acids are stick margarine; vegetable shortening; commercially prepared baked items and fried fast foods.
Recommendations
Guidelines set forth by the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS), recommend that your total fat intake should not exceed 35 percent of your daily calories. A person who eats a 1,800-calorie a day diet should consume 70g or less of fat per day.
