['Although numerous studies have reported negative associations between sleep duration and body size, no studies of this association have focused on Hispanic groups, which was the goal of this work.', 'Data are from adults in the 1982-1984 Hispanic Health and Nutrition Examination Survey (HHANES), which enrolled Cuban-Americans, Mexican-Americans, and Puerto Ricans. HHANES included self-reported sleep duration and several anthropometric measures. Principle component analysis extracted a single variable to represent body size. Linear regression models stratified by Hispanic group predicted body size from sleep duration adjusting for age, sex, education, income, marital status, household size, and acculturation.', 'Average age was 36-44 years and 52-64% were women. Average sleep duration was 7.3-7.7 h. Shorter sleep duration was associated with larger body size in Mexican-Americans only. The regression coefficient indicated that on average a Mexican-American adult who reported sleeping for 4 h would have a body size that was larger by 0.12 times the standard deviation for body size than a Mexican-American adult reporting 8 h of sleep (all other covariates being equal). This effect was similar to the effect of 10 years of age, which would be associated with an increase in body size by 0.10 times the standard deviation of body size.'] Does association between sleep duration and body size differ among three Hispanic groups?