The Mediating Effect of Sleep Duration on the Association between Food Insecurity and Childhood Obesity

Background: Childhood obesity has increased globally during the past four decades. Food insecurity could heighten the risk of obesity. However, little is known about the underlying mechanism. This study aims to investigate the mediating role of sleep duration in the association between food insecurity and childhood obesity and whether there are differences by age, sex, and race/ethnicity. Method: Data from the National Survey of Children's Health for the years 2016–2020 were used, including children 10–17 years of age. We employed causal mediation analysis within a counterfactual framework to decompose the total effect of food insecurity into natural direct and indirect effects and estimate the proportion mediated. Result: The prevalence of obesity was 15.8% in our study sample. Children with food insecurity had 78% higher odds [odds ratio (OR) = 1.78, 95% confidence interval (CI): 1.70–1.86] of having obesity compared with children who were food secure. Overall, only 6.13% of this association was mediated by sleep duration. The association between food insecurity and obesity was stronger in females (OR = 1.96, 95% CI: 1.84–2.10) than males (OR = 1.66, 95% CI: 1.56–1.75), but the proportion mediated by sleep duration was larger in males (7.13%) than females (5.22%). Evidence of mediation was more pronounced in children 10–11 years of age and non-Hispanic Asian children (proportion mediated = 14.85% and 11.21%, respectively). Conclusion: Food insecurity is associated with an increased prevalence of obesity among children. Although a small proportion of this association is mediated by sleep duration, these results suggest that sleep should be considered when assessing the link between food insecurity and childhood obesity.