A canny, relaxed approach to the problem of childhood obesity: rather than trying to lose weight, pediatrician Silberstein advises youngsters, think of maintaining your weight until you grow into it. This angle--you're not fat, just too short for your weight--is more likely to prove successful than an adult-type reducing regimen, says Silverstein, not only because it's less punitive and guilt-producing, but also because it lessens the chance for nutritional deficits to occur in a growing child. What he proposes, then, is a balanced maintenance diet: plan menus, count calories, use exchange lists to plan the daily food intake from each food group. Also on tap are the usual behavior-mod tricks: keep a log, eat slowly, eat only at the table, etc. And, among the non-standard attractions: the special hazards of Scarsdale- and Atkins-type dieting in children (they are particularly vulnerable to metabolic disorders) and the potential benefits of well-run camps for overweight-kids. Rounding out the coverage is a caution against undereating. All in all; a helpful, unhackneyed little guide--which valuably supplements even the best of the general advisories, Dr. Eden's Diet and Nutrition Program for Children.