Fat plays many important roles in a healthful diet. It provides energy and essential fatty acids, which are necessary for good health. It helps to maintain healthy skin and to regulate cholesterol metabolism, and it contributes to substances in the body called prostaglandins, which regulate other body processes. Dietary fat aids in the absorption of the fat-soluble vitamins A, D, E, and K, and it helps to satisfy the appetite by making you feel full after eating.
Despite all the important functions of fat, there is clear evidence that a diet that is too high in fat can contribute to many health problems, including some types of cancer, heart disease, diabetes, and obesity. High intakes of saturated fat, trans fat, and cholesterol increase the risk of unhealthy blood fat levels. In general, a healthy amount of fat in the diet ranges between 20% and 35% of total calories. Consuming more than 35% of total calories as fat can lead to a high intake of saturated fat and can also make it difficult to keep calorie intake at a desirable level.
Types of dietary fat
Being selective about the types of fat you eat is important for your heart health. Saturated fat and trans fat raise low-density lipoprotein (LDL, or “bad”) cholesterol levels in the blood, which raises the risk of developing heart disease. Trans fat additionally decreases high-density lipoprotein (HDL, or “good”) cholesterol levels.
The American Diabetes Association’s (ADA) latest nutrition recommendations advise getting less than 7% of calories from saturated fat and minimizing intake of trans fat. For a person who consumes 1500 calories per day, 7% of calories from saturated fat is less than 12 grams of saturated fat per day. (When converting grams of fat into calories, remember that each gram of fat contains 9 calories. Therefore, 1500 x 7% = 105 calories. 105 ÷ 9 = 12 grams.) Cooking oils contain varying amounts of saturated fat, but because they are not hydrogenated during processing, they do not contain trans fat.
Dietary cholesterol is a fatlike substance found only in foods of animal origin. It, too, can raise LDL cholesterol levels, which is why the ADA recommends that people with diabetes limit their dietary cholesterol intake to less than 200 milligrams per day. However, all of the cooking oils reviewed in this article are vegetable oils, so they do not contain cholesterol.
The types of fat that appear to be good for heart health are monounsaturated fats, polyunsaturated fats, and a type of polyunsaturated fat called omega-3 fatty acids. Plant sources high in monounsaturated fats include most nuts and certain vegetable oils, including canola oil, olive oil, high-oleic safflower oil, and high-oleic sunflower oil. Plant sources high in polyunsaturated fats include walnuts, flaxseed, and some vegetable oils, including soybean oil, corn oil, regular safflower oil, and canola oil.
Omega-3 fatty acids are found primarily in seafood, especially higher-fat, cold-water fish such as mackerel, salmon, sardines, albacore tuna, and lake trout. However, there are some plant-based products that are high in omega-3 fatty acids, including soybean oil, canola oil, flaxseeds, and walnuts. Omega-3 fatty acids lower the risk of heart attacks by preventing blood platelets from clotting and sticking to artery walls.
Most cooking oils naturally provide 10% to 20% of the Daily Value for vitamin E. Some products, such as Hollywood Enriched Expeller Pressed Safflower Oil, contain added vitamin E and may provide up to 30% of the Daily Value. Check the Nutrition Facts panel on the label for an oil’s vitamin content.