Association between dietary folate intake and obesity in children and adolescents: a cross-sectional NHANES study

The global prevalence of childhood and adolescent obesity has reached epidemic proportions. While evidence suggests an inverse relationship between dietary folate intake and adult obesity, whether this association persists in the younger population remains unclear. To examine whether dietary folate intake correlates with obesity in children and adolescents. Drawing upon the National Health and Nutrition Examination Survey (NHANES), the study modeled the correlation between dietary folate and overweight/obesity or central obesity through logistic regression models and restricted cubic splines in children (aged 6–11) and adolescents (aged 12–19). Sensitivity analysis was conducted to verify the robustness of the correlation. Stratified analysis examined potential differences across populations. This study included a total of 9,404 participants. In the fully adjusted model, dietary folate intake was negatively correlated with overweight/obesity (OR = 0.89, 95%CI: 0.83–0.97, P = 0.005) and central obesity (OR = 0.87, 95%CI: 0.80–0.94, P < 0.001) in children and adolescents. This correlation was non-linear (P-non-linear < 0.001). When dietary folate intake was below 1.90 and 1.95 (i.e. 190 and 195 mcg/1000 kcal), an increase of 100 mcg/1000 kcal was associated with a 35% reduction in overweight/obesity odds (OR = 0.65, 95%CI: 0.56–0.75, P < 0.001) and a 34% reduction in central obesity odds (OR = 0.66, 95%CI: 0.57–0.77, P < 0.001). Stratified analysis showed that the association was not significant in the children group, but significant in the adolescent group, with the dietary folate intake-central obesity association only existing in female adolescents. Sensitivity analysis supported the robustness of the above association. The results of this study indicate that when dietary folate intake is below the threshold (190 mcg/1,000 kcal and 195 mcg/1,000 kcal, respectively), its increase is negatively correlated with the odds of overweight/obesity and central obesity in children and adolescents. This study provides important epidemiological clues and scientific hypotheses for exploring dietary intervention strategies for children and adolescents with obesity in the future.