All Fats Are Not Created Equal

You need to consume some fat to maintain good nutrition, but many Americans eat more fat than they need. The American Heart Association (AHA) recommends that between 25 and 35 percent of your total calories come from fat, and the U.S. Department of Agriculture's Dietary Guidelines for Americans recommend a range of 20 to 35 percent.

You can improve your diet by putting a little knowledge of fats and oils into practice.

A gram of fat

Nutrition labels on food products and the nutritional analysis of recipes list the amount of fat in grams. You may find it easier to evaluate how much fat a food item or recipe contains by converting the grams into teaspoons.

Fats supply nine calories for each gram, compared with four calories per gram for carbohydrates and protein. Five grams of fat is equivalent to one teaspoon. So, a serving of chips with 12 grams of fat contains almost 2.5 teaspoons of fat and 108 calories; a bowl of ice cream with 34 grams of fat contains 6.8 teaspoons of fat and 306 calories.

Not all fats have the same makeup or effect on the body.

Saturated fats

These fats are found mainly in animal-based foods, such as red meat, poultry, lard, butter, cheese, whole milk, and whole milk products, and from palm and palm kernel oil, coconut oil, cocoa butter, and partially hydrogenated oils. They are solid at room temperature. Saturated fats increase the level of LDL (bad) cholesterol in your blood. The AHA suggests keeping the amount of saturated fats you eat to less than 7 percent of total daily calories. 

Polyunsaturated fats

These fats are found in corn, sesame, cottonseed, safflower, soybean, and sunflower oils. They are liquid at room temperature. They can reduce total cholesterol, as well as lower LDL cholesterol levels. They shouldn't be consumed in excess because they may also reduce the level of HDL (good) cholesterol. The fat in seafood is also mainly polyunsaturated.

Monounsaturated fats

These are the primary fats in olive, peanut, and canola oils and most other oils made from nuts and seeds. They raise HDL cholesterol as they lower LDL cholesterol. Monounsaturated fats are some of the healthiest fats you can eat, but they should be consumed in moderation.

Trans fats

Although trans fats are found naturally in small amounts in some foods, most trans fats are found in hydrogenated vegetable oils--such as margarines and shortenings--and in many commercially made crackers, cookies, frostings, pies, pastries, doughnuts, and fried foods.

The FDA now requires that trans fats be listed on food labels. You can also recognize trans fats if partially hydrogenated vegetable oil or margarine is listed among the ingredients.

Trans fats are created when hydrogen is attached to carbon in vegetable oil. The process converts some polyunsaturated fats to monounsaturated fats and some monounsaturated fats to saturated fats, giving the resulting product the properties of saturated fat. In the body, they act like saturated fat and tend to raise the blood cholesterol levels. They increase LDL and lower HDL cholesterol. The AHA recommends that trans fats make up less than 1 percent of your total daily caloric intake.

Cooking with oil and fat

The following guide to cooking with oils and fats will help you evaluate specific ingredients:

  • Butter has 108 calories and 12 grams of fat (almost 8 grams of saturated fat) per tablespoon. Because it's derived from animal fat, it also contains 33 mg of cholesterol per tablespoon. This double whammy of cholesterol and saturated fat makes it a less desirable choice than margarine.

  • Margarine contains no cholesterol, up to 2 grams of saturated fat and 34 to 100 calories per tablespoon. The softer the margarine, the less saturated it is. Margarine contains trans fat, so it shouldn't be used in excess. Tub margarines have the least amount of these fats.

  • Margarines are available that contain plant sterols and actually help reduce your cholesterol level. They are slightly more expensive but used over time can significantly reduce your cholesterol level. 

  • Olive oil has 120 calories and 14 grams of fat per tablespoon. It's considered one of the healthiest fats because 75 percent of its fat is monounsaturated and 13 percent is saturated.

  • Canola oil, which has the same number of calories and the same amount of fat as olive oil, is considered the second healthiest. Sixty percent of its fat is monounsaturated and 7 percent is saturated.

  • Vegetable oils such as corn or soybean rank third. They also have the same number of calories and the same amount of fat, but 20 percent of the fats are monounsaturated and 13 percent are saturated.

Remember: The best advice regarding fat in your diet is to follow the AHA guidelines, limiting the amount of fat to no more than 35 percent of your total calories.