Fats and Oils
Some fat is essential for normal body function. Fats can have good or bad effects on health, depending on their chemistry. The type of fat may be more important than the total amount of fat when it comes to reducing heart disease risk. Monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) are “good” fats that help promote heart health, and should be the main type of fats consumed. Saturated fats and trans fats (trans fatty acids) are “bad” fats that can contribute to heart disease, and should be avoided or limited.
Current dietary guidelines for heart health recommend that:
- Total fat from all fat sources should be 25 - 35% of total daily calories.
- Monounsaturated fatty acids (found in olive oil, canola oil, peanut oil, nuts, and avocados) and omega-3 polyunsaturated fatty acids (found in fish, shellfish, flaxseed, and walnuts) should be the first choice for fats.
- Omega-6 polyunsaturated fatty acids (corn, safflower, sunflower, and soybean oils and nuts and seeds) are the second choice and should account for 5 - 10% of total calories as part of total fat intake. Linoleic acid, the main omega-6 fatty acid found in food, has anti-inflammatory properties. Higher intakes of omega-6 fatty acids may help lower blood pressure and reduce diabetes risk.
- Limit saturated fat (found predominantly in animal products, including meat and full-fat dairy products, as well as coconut, palm oils, and cocoa butter) to less than 7% of total daily calories.
- Limit trans fats (found in stick margarine, commercial baked goods, snack and fried foods) to less than 1% of total calories.
All fats, good or bad, are high in calories compared to proteins and carbohydrates. In order to calculate daily fat intake, multiply the number of fat grams eaten by nine (one fat gram provides 9 calories, whether it's oil or fat) and divide by the number of total daily calories desired. One teaspoon of oil, butter, or other fats provides about 5 grams of fat. All fats, no matter what source they are from, add the same calories. The American Heart Association recommends choosing fats and oils that have less than 2 grams of saturated fat per tablespoon.
|Click the icon to see an image of saturated fats.|
|Click the icon to see an image of trans fatty acids.|
Try to replace saturated fats and trans fatty acids with unsaturated fats from plant and fish oils. Omega-3 fatty acids, which are found in fish and some plant sources, are a good source of unsaturated fats. Generally, two servings of fish per week provide a healthful amount of omega-3 fatty acids.
Fish oil dietary supplements are another option. Fish and fish oil supplements contain docasahexaenoic (DHA) and eicosapentaenoic (EPA) acids, which have significant benefits for the heart. Patients with heart disease, heart failure, or those who need to lower triglyceride levels may in particular benefit from fish oil supplements, provided under a doctor’s consultation.
|Click the icon to see an image of omega-3 fatty acids.|
Fat Substitutes. Fat substitutes added to commercial foods or used in baking, deliver some of the desirable qualities of fat, but they do not add as many calories. They cannot be eaten in unlimited amounts. They are considered most useful for helping keep down total calorie count.
- Plants substances known as sterols, and their derivatives called stanols, reduce cholesterol by blocking its absorption in the intestinal tract. Margarines containing sterols are available.
- Olestra (Olean) passes through the body without leaving behind any calories from fat. However, it can cause cramps and diarrhea, and even small amounts of olestra may deplete the body of certain vitamins and nutrients.
- Beta-glucan is a soluble fiber found in oats and barley.
Review Date: 04/02/2010
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.