Gender-specific relationships between socioeconomic disadvantage and obesity in elementary school students

To assess the gender-specific effect of socioeconomic disadvantage on obesity in elementary school students.

We evaluated body mass index (BMI) data from 2,648 first- and fourth-grade students (1,377 male and 1,271 female students) in eight elementary schools in Springfield, Illinois, between 2012 and 2014. Other factors considered in analysis were grade level, year of data collection, school, race/ethnicity, gender, and socioeconomic disadvantage (SD). Students were considered SD if they were eligible for free/reduced price lunch, a school-based poverty measure. We performed Fisher's exact test or chi-square analysis to assess differences in gender and obesity prevalence by the other factors and gender-stratified logistic regression analysis to determine if SD contributed to increased odds of obesity.

A higher proportion of SD female students (20.8%) were obese compared to their non-SD peers (15.2%) (p=0.01). Unadjusted and adjusted logistic regression analysis indicated no difference in obesity in SD and non-SD male students. However, in both unadjusted and adjusted analyses, SD female students had higher odds of obesity than their peers. Even after controlling for grade level, school, year of data collection, and race/ethnicity, SD female students had 49% higher odds of obesity than their non-SD classmates (odds ratio:1.49; 95% confidence interval: 1.09-2.04).

Obesity was elevated in SD female students, even after controlling for factors such as race/ethnicity, but such an association was not seen in male students. Further study is warranted to determine the cause of this disparity, and interventions should be developed to target SD female students.