Abstract: The association between relative skeletal age and fat patterning was analyzed using datafrom the Fels Longitudinal Study for boys at the chronological ages 8--17 years old. Fat patterning, as indicated by age-specific means for three skinfold thickness indices adjusted forweight/stature, was peripheral between 8 and 12 years of chronological age but began to in-crease in a centripetal direction towards a generalized distribution after 13 years old.From14 to 17 years of the chronological age, boys with advanced relative skeletal ages had more centripetal fat patterns, as indicated by the ratio subscapular/(subscapular + triceps) skinfold,than those with retarded skeletal ages. The mean annual increment in this ratio was significantly greater from 13 to 14 years of chronological age in boys with advanced relative skeletal agesthan in those with retarded relative skeletal ages. Fat pattern index scores at 17 years of chronological age, however, could not be predicted from relative skeletal ages at 7, 11 or 14 years oldafter ad justment for baseline fat pattern indexscores andweight/stature. It wasconcludedthat fat patterning, as quantified by the ratio indices used in this study, was associated onlyweakly with relative skeletal age in boys.Fat patterning may be associated morestronglywith other indicators of relative maturity such as secondary sex characteristics in adolescentboys.

Key words: Adipose tissue distribution; Skeletal age