Height, weight, and triceps skinfold were measured in 1,680 Mexican American children, 10 through 14 years of age, from the Lower Rio Grande Valley (LRGV) region of Texas. Study sample measurements were compared to those gathered in 1972 involving LRGV Mexican American children as well as National Center for Health Statistics (NCHS) reference data for American children. Independent t tests were used to determine the significance of differences between the study sample and the two comparison groups. Among the boys, for all ages, significant (.01) increases existed between the study sample and 1972 measurements with significantly greater (.01) triceps skinfold than NCHS data. Girls' height, weight, and weight/height ratio increased significantly (.01 to .05) for all ages from 1972, but triceps were significantly greater among only the 10 and 11 year olds. No significant triceps differences existed between study group girls and NCHS data. Results indicated considerable growth and increased adiposity among Mexican American children in the past decade with current levels comparing favorably to NCHS norms. Based on the results, it was concluded that these increases over the period studied were due to some form of dietary intervention rather than ethnic-genetic factors. (Author/NEC)