ObjectivesShort sleep duration has been associated with an increased risk of childhood overweight and obesity in high-income countries, but data from low- and middle-income countries are scarce. Independently, short sleep and food insecurity may increase the risk of overweight/obesity, but it is unknown whether they concurrently affect it. MethodsWe included 3350 adolescents aged 10-14 from the 2012 and 2016 Mexican National Health and Nutrition Survey. Short sleep was categorized as less than 9 hours for ages 10-12 and less than 8 hours for ages 13-14. Overweight/obesity was assessed via anthropometry. Modified Poisson regression models assessed prevalence ratios between short sleep and overweight, examining effect modification by food security status. Results86% met sleep duration recommendations. Short sleep was associated with an increased prevalence of overweight/obesity (prevalence ratio, 1.16; 95% CI, 1.05, 1.31). Multiplicative interaction was found between low and very low food security status and short sleep: adolescents in low food secure households with short sleep had 1.38 (95% CI: 1.10, 1.75) times the prevalence of overweight/obesity compared to adequate sleepers. Very low food secure households had 1.16 (95% CI: 1.14, 1.31) times the prevalence compared to adequate sleepers. This association was not significant in fully or marginally food secure households. ConclusionsShort sleep is associated with an increased obesity risk among Mexican adolescents 10-14years, particularly in the context of low and very low food security. These findings highlight the importance of addressing both sleep hygiene and food security in strategies to reduce obesity risk.