Eating is One of Life's Greatest Pleasures
Food choices depend on history, culture, and environment, as well as on energy and nutrient needs. People also eat foods for enjoyment. Family, friends, and beliefs play a major role in the ways people select foods and plan meals.
Foods Contain Energy, Nutrients, and Other Components That Affect Health
People require energy and certain other essential nutrients. These nutrients are essential because the body cannot make them and must obtain them from food. Essential nutrients include vitamins, minerals, certain amino acids, and certain fatty acids. Foods also contain other components such as fiber that are important for health. Although each of these food components has a specific function in the body, all of them together are required for overall health. People need calcium to build and maintain strong bones, for example, but many other nutrients also are involved.
The carbohydrates, fats, and proteins in food supply energy, which is measured in calories. Carbohydrates and proteins provide about 4 calories per gram. Fat contributes more than twice as much -- about 9 calories per gram. Alcohol, although not a nutrient, also supplies energy -- about 7 calories per gram. Foods that are high in fat are also high in calories. However, many lowfat or nonfat foods can also be high in calories.
Physical Activity Fosters a Healthful Diet
Calorie needs vary by age and level of activity. Many older adults need less food, in part due to decreased activity, relative to younger, more active individuals. People who are trying to lose weight and eating little food may need to select more nutrient-dense foods in order to meet their nutrient needs in a satisfying diet. Nearly all Americans need to be more active, because a sedentary lifestyle is unhealthful. Increasing the calories spent in daily activities helps to maintain health and allows people to eat a nutritious and enjoyable diet.