Restricting food intake can be harmful, especially during active periods of growth and vigorous physical activity. Dairy products are often the first food group to be restricted in a diet, and this may affect the development and maintenance of healthy bones. Also, dieting limits the overall amount of foods consumed, which may affect overall growth and development. Explain to your daughter that eating a variety of healthy foods can help her achieve optimal performance and endurance.

No. Coaches should never recommend weight loss for children or adolescents. This decision should be made by the child or adolescent and their parents in consultation with a health professional. Weight loss in children and adolescents can be harmful, especially during periods of growth and development.

No. Most physical activity protects male and female adolescents from eating disorders by improving their self-esteem and body image. You should be aware of any sudden change in your daughter's eating behaviors (for example, skipping meals, always requesting fat-free products, continually complaining about being fat, and participating in excessive physical activity).

There is little evidence that protein supplements improve children's or adolescents' physical activity performance. In fact, most are not regulated by the Food and Drug Administration, and some may be harmful. Explain to your son the potential risks of using supplements, and encourage him to eat healthy foods, including good sources of protein, to promote growth and development and optimal performance. Explain to your son that everyone grows at a different rate, and that differences in strength, endurance, ability, height, and weight reflect primarily genetics and the timing of growth. Encourage your son's interest in physical activity, and emphasize the importance of having fun, being healthy, and developing good sportsmanship. Applaud your son's efforts to pursue different activities, regardless of his skill level.

Yes. A low resting heart rate is a sign of good physical condition, but a heart rate less than 60 beats a minute in a child or adolescent can be a concern, and the child or adolescent should be evaluated by a health professional. A common cause of a too-low heart rate is malnutrition associated with decreased caloric intake and/or excessive physical activity.

Yes. Weight-bearing physical activities (for example, jumping rope, walking, running, and playing basketball) promotes the development and maintenance of healthy bones, but only if your daughter consumes enough calcium. Children ages 4 to 8 need to consume 800 mg of calcium per day, children and adolescents ages 9 to 18 need 1,300 mg per day, and adolescents ages 19 to 21 need 1,000 mg per day. If your daughter is lactose intolerant, a calcium supplement may be necessary. Calcium-fortified products (for example, orange juice) can also provide needed calcium. Female children and adolescents whose menstrual cycles have stopped or become irregular because of excessive physical activity and inadequate caloric intake are at risk for bone loss, even with adequate calcium intake.