Background The relationship of food insecurity with overweight and obesity is still discussed in the literature. This work aimed to explore if this apparently paradoxical association was observed in Paris metropolitan area.

Methods We used data from the “Health, Inequality and Social Breakout” (SIRS) cohort, a longitudinal health and socio epidemiological, population based and representative survey of the general population of the Paris metropolitan area. This cross sectional analysis was based on the 2010 data. Participants' BMI was estimated using self-reported height and weight and computed in a dichotomous variable (BMI <25 vs BMI ≥25). Food insecurity was estimated using the US HFSS and computed in a dichotomous variable: food secure vs food insecure (moderate/severe). Logistic regression models were estimated for men and women separately.

Results Overweight (BMI ≥25) prevalence was 39.8%. In men, nationality was significantly associated with being overweight: a European citizen has a higher risk of being overweight than a French one- (OR=2.89; p=0.002). In women, socio professional group was a significant determinant of overweight, with a higher risk for workers' (OR=5.37 p<0.001, ref= Executives). After adjusting for age, nationality and socioprofessional group, food insecurity was associated with overweight in women (OR=2.24, 95% CI [1.32 to 3.81]) but this association was not significant for men (OR=1.54, 95% CI [0.83 to 2.86]).

Conclusion Food insecurity seems to be a stronger determinant of overweight among women. It remains important to explore and understand the pathway through which this situation is associated with overweight, particularly in terms of nutritional problems and food assistance programs.