Secular change in height and weight of indigenous school children in Oaxaca, Mexico, between the 1970s and 2007

Background: Information on secular change in indigenous children in Oaxaca, southern Mexico, is limited. Aim: To evaluate secular change in heights and weights of indigenous school children 6-14 years in four regions of the state of Oaxaca between the 1970s and 2007. Subjects and methods: Heights and weights of 2897 (1419 boys, 1478 girls) and 4305 (2368 boys, 1937 girls) school children 6-14 years of age were measured in the 1970s (1971-1978) and 2007, respectively. The sample was from 18 communities in the 1970s and from 58 communities in 2007 in four regions of Oaxaca. Sex-specific MANCOVA, with age of the child and altitude of each community as covariates, was used to compare size attained in the 1970s and 2007 in two age groups: 6-9 years and 10-14 years. Results: Indigenous Oaxaca school children are taller and heavier in 2007 than the 1970s. Secular gains are larger in youth of 10-14 years than in children of 6-9 years, while sex differences are small. Conclusion: Improved growth status between the 1970s and 2007 presumably reflects better health and nutritional conditions in indigenous communities of Oaxaca. Mean heights in 2007, however, only approximate 5(th) percentiles of the US reference.