Background On the population level, the association of age and other sociodemographic factors with eating disorders (ED) is unclear.

Methods We used cross-sectional data from the French general population-based NutriNet-Santé e-cohort (n=49 603 adults; 76.3% women; mean age=50.4±14.6 years). ED were evaluated in 2014 with the 5-item SCOFF screening questionnaire and the Expali algorithmic tool. Likely cases of restrictive, bulimic, hyperphagic and other ED were the dependent variables. Age, marital status, education, occupation, physical activity and smoking were the independent variables. Associations were estimated via gender-stratified multivariable polytomous logistic regression.

Results Among women, age displayed inverse linear associations with both restrictive and bulimic ED, underscoring 18–25 years as the most vulnerable period (adjusted OR=3.37, 95% CI: 2.24 to 5.08 for restrictive ED; adjusted OR=2.98, 95% CI: 2.37 to 3.74 for bulimic ED, respectively). A similar association was observed in men regarding bulimic ED. In women, age was not associated with hyperphagic ED for which living alone, low education, low physical activity, being a homemaker/disabled/unemployed/retired, a manual worker or a former/current smoker had increased importance. In men, 18–39 years emerged as the least vulnerable period regarding hyperphagic ED (adjusted OR=0.74, 95% CI: 0.56 to 0.99). Across gender, having postsecondary education had significant inverse associations with all except restrictive ED, whereas being a student had a significant positive association with restrictive ED.

Conclusions The findings support gender-specific associations of age with four ED subtypes and could inform future prevention initiatives targeting specific ED among specific age groups.

Trial registration number NCT03335644; Pre-results.