New norms of upper limb fat and muscle areas for assessment of nutritional status.

Based on measurements of triceps skinfold thickness and upper arm circumference of a cross-sectional sample of 19,097 white subjects aged 1 to 74 yr, derived from the United States Health and Nutritional Examination Survey of 1971 to 1974, the arm muscle circumference, arm muscle area, and arm fat area were calculated. Thereafter, age- and sex-specific percentiles for all three estimates of upper arm tissues were obtained. Based on empirical and theoretical evidence, it is recommended that assessments of nutritional status be made on the basis of areas of fat and areas of muscle rather than direct skinfold thickness and arm circumference. It is also recommended that these new norms should replace those currently in use.