ABSTRACT
Body composition of both younger and older subjects was estimated using several different methods in order to evaluate their use with elderly subjects. Estimates were obtained by dual energy x-ray absorptiometry, underwater weighing, bioelectrical impedance analysis, and skinfold measurement in 48 younger subjects (26-40 years) and 44 older subjects (65-85 years). In older men and women the underwater weighing percent fat estimates were significantly higher than all other methods. Bone mineral explained a significant proportion of the variance in the difference between the dual energy x-ray absorptiometry and underwater weighing estimates of percent fat (R2 = 0.442-0.627). Because of its insensitivity to variability in bone mineral, we recommend that the underwater weighing method be not used to estimate percent fat in older men and women. Dual energy x-ray absorptiometry provides an alternative which accounts for the age-related decrease in bone mineral density.
