The American Heart Association recommends a diet in which not more than 30 percent of total caloric intake is from fats. The nutrition labels that now appear on most cans, milk cartons, and other food packages show how much protein, carbohydrate, and fat a serving contains in gram weight. A calorie measures the energy value of food, not its fat content.

A calorie is actually the amount of heat needed to raise 1 kilogram of water 1° centigrade. Using a 30 percent guideline, the average 2,000-calorie-per-day diet should contain no more than 600 calories from fat.

Nutrition labels also show the percentage of recommended daily nutrient intake contained in a serving of food. These percentages are based on the U.S. Department of Agriculture (USDA) Food and Nutrition Service estimate of 2,000 calories per day for the average daily diet.

Actual caloric intake will and should vary with age, gender, weight, and activity level. In general, men and young adults need more calories than do women and older adults. Pregnant and breastfeeding women need more calories, as well.

Based on 2,000 calories per day, the USDA suggests the following nutrient levels:

The USDA also recommends:

• maintaining a diet high in grains, vegetables, and fruits

• maintaining a diet low in fat, saturated fat, and cholesterol

• maintaining a diet with a moderate intake of sugar, salt, and sodium

• eating a variety of foods