According to WebMd, the amount of calories a person needs each day is based on his weight, age, gender and whether he wants to lose, gain or maintain his weight. To maintain weight, women ages 19 to 30 with a body mass index of 21.5 need 1800-2000 calories if they lead relatively inactive lifestyles. Males in the same age range with a BMI of 22.5 need 2400-2600 calories.Continue Reading
Additionally, more active people can consume more calories. For example, active men ages 19 to 30 with a BMI of 22.5 can consume 3000 calories, and active women ages 19 to 30 with a BMI of 21.5 can eat 2400 calories. To lose weight, caloric intake should be reduced by 500 each day. To gain weight, 500 calories are added each day for each pound desired within a week.
Adults aged 51 and older require fewer calories, states the Academy of Nutrition and Dietetics. Older women with sedentary lifestyles need 1600 calories, and more active older women need 1800-2200 calories. Older men with inactive lifestyles need 2000 calories, while very active older men need 2200-2800 calories. The United States Department of Agriculture offers a daily food plan calculator on its website that can help people determine what foods they need to consume each day, based on age, gender, activity level, weight and height.Learn more about Nutritional Amounts & Limits