Age- and maturity-related changes in body composition during adolescence into adulthood: the Fels longitudinal study

We examined patterns of change in body composition from 8 to 20 yrs of age and the effects of rate of maturation on these patterns using serial data for total body fat (TBF). There is a continual increase, but a declining rate of change with age in TBF. For %BF the same pattern as for TBF exists for females, but for males the pattern of change in percentage body fat (%BF) reflects the concurrent changes in fat free mass (FFM). For FFM, there is an increase in females that slows at older ages, but in males there is a continual rapid increase until young adulthood. There is marked tracking for body composition persisting from childhood to adulthood. At the same age, rapidly maturing children have significantly larger TBF, %BF and FFM than slowly maturing children.