A person's caloric requirement depends on his body size and exercise level. Sedentary people of both genders will keep their weight stable by taking in about 13 calories per pound of body weight each day. Moderate physical activity boosts this requirement to 16 calories a pound, and vigorous exercise calls for about 18 calories a pound. On average, a moderately active 125-pound woman needs 2,000 calories a day; a 175-pound guy with a similar exercise pattern needs 2,800 calories. And like women, men will lose weight only if they burn more calories than they take in.
Poor nutrition may be one of the easiest conditions to self-diagnose. Look at the food pyramid and the suggested servings. Look at your diet. Are you getting the recommended daily amounts of fruits and vegetables? Enough calcium? Read the labels and compare what you eat to what you need. You may discover that even if your weight is ideal, you are not getting enough nutrition.