Body composition and physical activity in 8-year-old children.

Body measurements and determinations were made of normal children age 8 3/4 yr. Anthropometric indices most highly correlated with percentage fat as determined by body density were the sum of four skinfolds, relative weight, and triceps skinfold thickness. Girls had a significantly higher percentage of fat than boys. Percentage fat at this age was compared to longitudinal activity scores (based on 1-day activity records) obtained from 6 months to the current age. There was no significant correlation of activity with fatness in girls. In boys, activity at 3 and 4 yr had a significant negative correlation with fatness at age 8; activity at age 8 was not correlated. Relative-leanness-fatness was better related to past than current activity. Comparison of longitudinal activity scores revealed a continuity of activity patterns for short intervals (e.g., 1 yr), but over longer periods (e.g., 4 or more yr) the effect diminished.