Location: Children's Nutrition Research CenterTitle: Components of the diet associated with child adiposity: a cross-sectional study) Author
Submitted to: Journal of American College of Nutrition
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/8/2011
Publication Date: 12/1/2011
Citation: Ledoux, T.A., Watson, K., Barnett, A., Nguyen, N.T., Baranowski, J.C., Baranowski, T. 2011. Components of the diet associated with child adiposity: a cross-sectional study. Journal of American College of Nutrition. 30(6): 536-546. Interpretive Summary: Identifying the dietary factors that contribute to obesity would be important to target foods, food groups, or nutrients that could be changed to prevent obesity. In a large data set of 9-10 and 17-18 year olds, we found that children who ate more calories were lower in weight, which is not biologically plausible. When we corrected for over-reporting and under-reporting of calorie intake, we found the expected relationships. Energy intake (total calories), vegetables, refined grains (e.g. cakes), total fat, total protein and total carbohydrate were positively related to BMI z-scores, and artificially sweetened beverages were positiviely related to waist circumference. Research in large longitudinal studies will be needed to understand these relationships.
Technical Abstract: This study sought to determine which components of youths' diets were related to adiposity while controlling for potential often-neglected confounders such as moderate to vigorous physical activity (MVPA) and dietary reporting error. Secondary goals of this study were to determine the extent to which MVPA confounded the associations between diet and adiposity and whether associations between diet and adiposity would differ depending on reporting error. An ethnically diverse urban sample of 342 children aged 9-10 years and 323 adolescents aged 17-18 years were recruited for this cross-sectional study. Body mass index (BMI) and waist circumference (WC) were measured in the school; dietary assessment included three 24-hour recalls via telephone in the evenings, and MVPA assessment included 5 days of accelerometry. Over (n = 68), under (n = 250), or plausible (n = 347) dietary intake reporters were identified with the Huang calculation method. Linear regression assessed the relationship between adiposity indicators (BMI z-score and WC) and components of the diet (energy intake, food groups, macronutrients) after controlling for reporting error, demographic variables, and MVPA. When dietary reporting error and potential confounders such as MVPA and demographic variables were controlled, energy intake (EI), vegetables, refined grains, total fat, total protein, and total carbohydrate were positively related to BMI z-score and WC and artificially sweetened beverages to WC. MVPA was a significant confounder. For BMI z-score, but not WC, relationships and strength of these relationships differed depending on dietary reporting error group (plausible, underreporter, overreporter). Among plausible reporters, as expected, EI, refined grains, and all macronutrients were positively related to adiposity; however, artificially sweetened beverages and vegetables, which are low-energy-dense foods, were also positively related to adiposity. Reporting error interfered with associations between diet and BMI z-score but not WC, suggesting WC is a more robust measure of adiposity in relation to diet.