To prevent obesity, physical activity should begin in infancy; this will increase LBM and thereby calorie needs. Skinfolds and circumferences (abdominal and thorax skinfolds and waist circumference) which significantly correlated with body fat should be used clinically. Calorie needs according to LBM should be reduced to 50% of the RDA or approximately nine cal/cm height for maintenance or seven cal/cm height for weight loss in MM children after age six (possibly at three to four years of age if nonambulatory).