The relationship between BMI and dietary intake of primary school children from a rural area of South Africa: The Ellisras longitudinal study

Objectives: To investigate the relationship between dietary intake and BMI of primary school children from a rural area of South Africa cross-sectionally. Both under and over nutrition remain major health problems in South Africa. In rural areas, where especially undernutrition leads to child morbidity and mortality, determinants should be detected. Methods: Data was used from 825 children (421 boys, 404 girls), aged 6-12 years, participating in the Ellisras Longitudinal Growth study. Height and weight were measured in accordance with the protocol of the International Society for the Advancement of Kinanthropometry. Internationally recommended cut-off points for body mass index (BMI) were used. Dietary intake was measured using the 24 h recall method. In general, boys and girls from Ellisras had dietary intake levels lower than or according to dietary guidelines. Results: A singular linear regression model showed a significant association between monounsaturated fat and BMI. The multiple model demonstrated that total fat (B=0.05, CI: 0.019-0.082), monounsaturated fat (B=-0.093, CI: -0.160 to -0.026) and polyunsaturated fat (B=0.056, CI: 0.09-0.02) predict BMI. Conclusion: This study supports previous findings about BMI and dietary trends in rural areas of South Africa. Despite low fat intake of the subjects, this macronutrient appeared to predict BMI most strongly. More research is needed; however, to further examine how healthy their lifestyle is nowadays with respect to diet and into what extent the nutrition transition has reached this area. Am. J. Hum. Biol. 26:701-706, 2014. © 2014 Wiley Periodicals, Inc