Evidence for a secular change in obesity, height, and weight among Navajo Indian schoolchildren.

A survey measuring heights and weights of 1969 schoolchildren residing on the Navajo Indian Reservation was conducted in 1989. The findings were compared with National Center for Health Statistics (NCHS) reference data and with surveys of Navajo children from 1955, 1968, and 1981. Approximately twice as many children exceeded the 95th percentile of weight-for-age (11.2% of girls, 12.5% of boys) than would be expected for the NCHS reference population. The mean weight-for-height z scores exceeded those for the NCHS reference population for all ages in both sexes. Compared with data from 1955, mean heights increased 6.1% among boys and 4.4% among girls whereas mean weights increased 28.8% among boys and 18.7% among girls across all age groups. The data suggest that there has been a secular change in height, weight, and obesity in Navajo Indian children over the past 35 y.