Getting to the Heart of a Healthful Diet: Fats
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Getting to the Heart of a Healthful Diet: Fats

American Heart Association recommendation: Limit foods high in saturated fat, trans fat, and/or cholesterol, such as full-fat milk products, fatty meats, tropical oils, partially hydrogenated vegetable oils, and egg yolks. Instead choose foods low in saturated fat, trans fat, and cholesterol.

Choose fats with 2 grams or less of saturated fat per serving, such as liquid and tub margarines, canola oil, and olive oil.

Here's Why:

The major kinds of fats in the foods we eat are saturated, polyunsaturated, monounsaturated, and trans fatty acids. Saturated fats, trans fats, and dietary cholesterol raise blood cholesterol. A high level of cholesterol in the blood is a major risk factor for coronary heart disease, which leads to heart attack.

Dietary cholesterol affects blood cholesterol levels to a much lesser degree than was originally thought, and also much less than saturated and trans fat. Since saturated fat and cholesterol are often found together in foods, by limiting saturated fat, cholesterol intake will go down as well.

Both types of unsaturated fats may help lower your blood cholesterol level when used in place of saturated fats in your diet.

Be moderate in eating all types of fat because fats contain more than twice the calories of either protein or carbohydrate. One gram of fat contains nine calories, while one gram of protein or carbohydrate provides four calories.

Here's How:

Foods often have more than one type of fat. As a general rule, those that have mostly saturated fat are thicker (ie, butter, lard, cream), while those that are mostly unsaturated are thinner (ie, oils).

Saturated Fat

Foods rich in saturated fat include:

  • Whole milk
  • Cream
  • Ice cream
  • Whole-milk cheeses
  • Butter
  • Lard
  • Meats
  • Palm and palm kernel oil
  • Coconut oil
  • Cocoa butter

Many snack foods and fried foods are also rich in saturated fat. Check the Nutrition Facts label to find the saturated fat content of a specific food.

For many of these foods that are naturally rich in saturated fat, there are low-fat versions. Some are more palatable than others, so try a variety of them to find ones you like. Use these lower-fat versions, or use the original versions very infrequently. Also, try to choose naturally lower-fat foods. For example, have fruit and gingersnaps for dessert instead of ice cream. And eat fish and vegetarian-based dinners several times a week in place of meat.

Trans Fat

Through the process of hydrogenation, trans fats are made. This process takes a vegetable oil, which is naturally high in unsaturated fatty acids, and adds hydrogen molecules to it to make it more saturated and more solid. Depending on how many hydrogens are added, the result of this process can be a hydrogenated oil or a solid margarine. These products do not contain cholesterol, as butter does; any food that comes from a plant does not contain cholesterol.

Hydrogenated oils are used to make many processed snack foods.

Foods rich in trans fat include:

  • Margarine
  • Cookies
  • Crackers
  • Cakes
  • French fries
  • Fried onion rings
  • Donuts

Unlike saturated fats, trans fats are not listed on the Nutrition Facts food label. Look at the ingredient list—if "hydrogenated oil" or "partially hydrogenated oil" is listed, that means the food contains trans fat.

According to the American Heart Association, hydrogenated fats in margarine and other fats are acceptable if the product contains liquid vegetable oil as the first ingredient and no more than 2 grams of saturated fat per tablespoon.

Trans fats significantly increase the risk of heart disease (much more than saturated fats) by raising low-density lipoprotein (LDL) cholesterol levels (so called “bad cholesterol”) and lowering high-density lipoprotein (HDL) cholesterol levels (“good cholesterol”). They also increase your body’s propensity to form blood clots, which again increases the risk for coronary events. There are no safe limits in terms of consumption of fatty acids. New York City has recently banned use of trans fats in restaurants.

Butter vs. Margarine

Since both the saturated fat in butter and the trans fat in margarine can raise blood cholesterol levels, which is the best one to eat? There is no definitive answer to this question. When choosing your spread, consider the following:

  • The softer the better:
    • Whipped butter has less saturated fat than stick butter
    • Liquid and soft tub margarine contain little saturated fat or trans fat
  • Whichever you choose, limit the amount you use
  • When cooking and baking, substitute an unsaturated oil (see below) for butter or margarine

Unsaturated Fat

You can feel good about eating this type of fat! But unsaturated fats still deliver as many calories as the saturated varieties, so don't go overboard.

Foods rich in polyunsaturated fats include:

  • Certain oils:
    • Safflower
    • Sesame
    • Soy
    • Corn
    • Sunflower-seed
  • Nuts
  • Seeds

Foods rich in monounsaturated fats include:

  • Certain oils:
    • Olive
    • Canola
    • Peanut
  • Avocados

It's easy to work these foods into your diet:

  • Combine nuts, seeds, dry cereal, and dried fruit for a snack mix.
  • Use mashed avocado as a sandwich or bagel spread.
  • In sesame oil, sauté vegetables, tofu, and peanuts.
  • Bake pecans or walnuts into breads, pancakes, and muffins.
  • Use an oil sprayer for your cooking oils; spray meats and vegetables and sprinkle with herbs before cooking.
  • Coat salmon or tuna steaks in sesame oil and sesame seeds before broiling.


International Food Information Council

American Heart Association


Information on trans fat. US Food and Drug Admisnitration. Available at: Accessed January 17, 2007.

Mensink RPM, Katan MB. Effect of dietary trans fatty acids on high-density and low-density lipoprotein cholesterol levels in healthy subjects. N Engl J Med. 1990;323:439-445

Wahrburg U. What are the health effects of fats? Eur J Nutr. 2004;43(suppl 1):1/6-1/11.

Last reviewed January 2007 by Marcin Chwistek, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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