We compared anthropometric data (height, weight and body mass index) from 19 geographically and ethnically varied samples of community-dwelling elderly people. Participants were stratified into three age groups, 60-69, 70-79 and 80 years or older. We present age-group-specific means and standard deviations for height, weight and body mass index (BMI, weight/height2) and the prevalence of underweight (BMI < 20) and overweight (BMI > or = 30). Across studies there are large differences in the prevalence of overweight and underweight, but in all studies mean height and BMI decreased with age. In general, mean BMI among 70-79-year-old women is greater than that for men of a similar age, and the Mediterranean samples are heavier for height than samples from Western Europe, Asia, Africa and the United States. The comparisons suggest that the sensitivity and specificity of a fixed cut-off for underweight and overweight are likely to differ by sex, age, and geographic location in samples of older persons.