During periods of rapid growth such as puberty, the body needs extra nutrition especially protein to build muscles, calcium to build bones and strengthen teeth, vitamins, and minerals. In addition, a girl’s diet during puberty will affect both her own health and that of her infant many years later. But both sexes need three square meals a day, plus healthy snacks of milk, fruit, and the like.
The chief culprits in adolescent subnutrition are skipping meals, mainly breakfast, going on crash diets, and filling up on junk food. Candy bars and fries don’t cause acne, and Twinkies don’t cause violent mood swings. But neither do they provide the young adolescent’s body with the building materials it needs to grow.
Most adolescents are unhappy with their shape. Typically, boys worry about being skinny and underdeveloped; girls more often worry about not being thin enough. This new self-awareness can lead to healthy attempts to trim down or build up to an unhealthy preoccupation with eating and/or dieting.
It’s important to both parents and teenagers to know what is normal. Changes in weight and proportion are to be expected during puberty, the average teenager puts on 10 pounds a year between the ages of 10 and 14. But development is not always even. A girl may fill out before she reaches her full height and so looks chubby for a time; a boy may grow before he fills out and appears skinny.
Begin by measuring your adolescent’s height and finding on the appropriate height chart, the corresponding percentile for a boy or girl under that age. Now, using that percentile, look on the weight chart to see how much the adolescent’s weight is over or under what might be expected. For example, a 14-year-old girl who is 5-feet-3-inches tall is at about the 50th percentile in height for her age. The 50th percentile in weight for 14-year-old girls is about 110 pounds. This is the figure against which a 14-year-old girl of this height should compare her actual weight.
Averages, of course, do not reflect differences in build and activity level. In general, an adolescent who is within 10 percent of the expected weight for someone of the same height and age (in the case of the 14-year-old girl above, between 99 and 121 pounds) is well within the normal range. If an adolescent’s weight is 20 percent or more above the expected figure, parents should be concerned. While being slightly underweight is less cause for concern, sudden or dramatic weight loss may be a sign of serious medical problems, or if self-induced, psychological problems.
For many adults, fitness has reached the level of a fad. In contrast, today’s children and adolescents are fatter and flabbier than the children of two decades ago. A surprising number lags behind their active, middle-aged parents in cardiovascular fitness. One reason for this is that adolescents lead more sedentary lives today. They are less likely to walk to school or bike to their friends’ houses and more likely to spend hours in front of the TV.
Another problem is that schools emphasize competitive sports. The minority of adolescents who make a team spend hours after school in training. But the average student gets only two or three hours of physical education a week, and much of that time is spent standing around. Moreover, participation in football, basketball, hockey, and other competitive sports is usually limited to the school years.
It is a good idea for parents to encourage physical activities outside school that offers lifelong participation such as swimming, tennis, hiking, jogging, biking, walking, and the like. In addition to promoting physical fitness, sports help adolescents relieve tension, build self-confidence, make friends, and generally feel good about themselves.
Many adolescents have trouble getting up in the morning, fall asleep in the afternoon, and generally seem to have less energy than they did as children. Part of the reason, of course, is that they are staying up later (watching TV, talking to friends, reading, or studying).
But part of the reason is biological: At puberty, there is a shift in the normal sleep cycle, leading individuals to crave later bedtimes and as a consequence, more sleep in the morning. (When your young adolescent complains about no longer feeling tired at his old bedtime, or feeling exhausted when awakened for school, he is probably telling the truth.) In any case, many of the hormones that stimulate pubertal development are released during sleep. Sleep is as important to adolescent health as diet and exercise.