Association between overweight and obesity with school performance in secondary students in Merida, Mexico

Background: Some studies have found a negative relationship between obesity and school performance in scholars. However, this topic has not been studied in depth in Mexico. The aim of this study was to analyze the association between overweight and obesity with school performance in secondary school students from Merida. Methods: Weight and height were measured, and body mass index was calculated in a sample of 566 secondary students in Merida. Nutritional status was classified in normal weight (-2-<+1 standard deviation [SD]), overweight (+1-<2 SD) and obesity (>+2 SD) according to the World Health Organization criteria. The scores in language, mathematics and sciences were used as indicators of school performance. Good performance was considered when the scores were >= 8 points, and poor performance when scores were <8 points. Logistic regression models were used to analyse the association between the variables. Results: The 44% of the sample met the criteria for overweight and obesity. After adjusting for school grade, type of school, number of absences, and Mayan surnames, we found that girls classified as obese had a significant risk of a poor performance in mathematics (odds ratio [OR]: 3.07; 95% confidence interval [CI]: 1.39-6.80) and language (OR: 2.55; 95% CI: 1.14-5.71) compared with those with healthy weight. Conclusions: Our results suggest that obesity represents a risk of having a lower school performance in girls but not in boys.