The social pressure to maintain a particular body type can lead to bulimia and anorexia in teenage girls. From birth, all individuals have unique body types and caloric requirements, and early attempts to lose weight may result in negative health consequences. Parents can help teenage girls focus more on exercise and eating a balanced diet, rather than drastically cutting calories. Consult with your teen's doctor before beginning any weight loss program.
Total Caloric Needs
Age, body composition and physical activity level determine your teens total daily caloric needs. Your teen can calculate her basal metabolic rate, or the rate at which her body burns the calories she eats, and combine this with her physical activity level through a formula called the Harris-Benedict Equation. An online calculator provides he easiest way to determine daily caloric requirements. The United States Department of Agriculture estimates that a moderately active teenage girl requires about 2,000 calories each day. Sedentary and active teenage girls require about 1,800 and 2,400 calories, respectively.
Calories to Lose Weight
A teenage girl will ultimately need to obtain a negative energy balance of 3,500 calories to lose 1 pound of body fat. She can do this through dieting, increasing her activity level, or both. If she restricts her caloric intake by 500 calories a day, about the maximum safely recommended by the National Strength and Conditioning Association, she can lose 1 pound of body fat each week. For example, if the body requires 2,000 calories each day to maintain its weight, a teenage girl will lose 1 pound of body fat each week by consuming 1,500 calories each day.
Dieting or not, your teenage girl needs to consume an optimal balance of the three macronutrients: carbohydrates, fat and protein. For a teenage girl, about 45 to 65 percent of total caloric intake should come from carbohydrates, 25 to 35 percent from fat and 10 to 30 percent from protein. If she follows a 1,500-calorie diet, she should consume about 750 calories from carbohydrates, 450 from fat and 300 from protein.
Warnings and Tips
Avoid restricting the caloric intake by more than 500 calories a day. Because food provides about 20 percent of a person's fluid needs, rapid weight-loss programs can result in dehydration. Severe caloric restriction can result in inadequate nutrient intake, placing teenage girls at risk of illness, growth stunts, amenorrhea and organ damage. The best weight-loss programs include just modest caloric restriction, a balanced diet and increased physical activity. The USDA recommends getting the physical equivalent of walking more than 3 miles a day at a moderate pace, in addition to any activity associated with daily life to maintain an active physical activity level. For general cardiovascular health and weight control, the American College of Sports Medicine advises getting 30 minutes of aerobic exercise at least five days a week.