Abstract
Objectives. To determine whether obesity during the pre-school to primary school years was related to math performance, independently of other factors, in a large representative sample of Canadian children. Our main hypothesis was that obese children would obtain lower overall math scores than their non-obese peers. Methods. Participants of the National Longitudinal Survey of Children and Youth comprised the sample for our analysis (n=4 664). Obesity was based on mother-reported height and weight and IOTF age- and sex-specific body mass index cut-offs, and was assessed when the cohort was aged 2–5 years and 8–11 years. Children were classified as ‘never obese’, ‘grew out of obesity’, ‘developed obesity’ or ‘always obese’, depending on their obesity status at these two time points. The outcome was performance on a standardized math test that was administered when the cohort was aged 8–11 years. Statistical analysis was conducted using multivariate linear regression methods. Results. Children who ‘grew out of obesity’ scored on average 11 points higher on the math test (p<0.0001) than children who were ‘never obese.’ Children who were ‘always obese’ and those that ‘developed obesity’ performed no differently on the math test than children who were ‘never obese’. No interactions between sex and obesity status were found. Conclusions. Childhood obesity in this study did not lead to poor math performance. Being obese in the pre-school years and normal weight in primary school, however, was associated with improved math performance. This finding points to a potential nutritional window for early child development.
Acknowledgements
The first author received the Ontario Graduate Scholarship from the Provincial Government of Ontario (Canada) to conduct this work.
Disclaimer: This analysis was based on the Statistics Canada NLSCY master files. All computations were prepared by Megan Ann Carter and conducted at the Carleton, Ottawa, Outaouais Local Research Data Centre, University of Ottawa, Ottawa, Ontario, Canada. The responsibility for the use and interpretation of these data is solely that of the authors. The opinions expressed in this paper are those of the authors and do not represent the views of Statistics Canada.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.