The Mediating Role of Overweight and Obesity in the Prospective Association between Overall Dietary Quality and Healthy Aging.

BACKGROUND

Our objective was to quantify to what extent the association between adherence to the French nutritional recommendations at midlife, measured by the Programme National Nutrition Santé-Guideline Score (PNNS-GS), and healthy aging (HA) is mediated by body mass index (BMI) status.

METHODS

We analyzed data from 2249 participants of the French 'Supplementation with Vitamins and Mineral Antioxidants' (SU.VI.MAX-'SUpplémentation en VItamines et Minéraux AntioXydants') cohort. At baseline (1994⁻1995), data on BMI status (<25 vs. ≥25 and <30 vs. ≥30) and diet were collected. At follow-up (2007⁻2009), HA status (yes/no) was evaluated via a multidimensional concept focusing on chronic disease incidence, physical and cognitive functioning, mental and social health, pain, and perceived health. Relative risks (RR) were estimated by extensively adjusted robust-error-variance Poisson regression, and counterfactual-based mediation analysis was performed.

RESULTS

Our HA criteria were met by 39% of participants. We identified a positive direct relation of a greater adherence to the French nutritional recommendations, with the probability of HA (RRQuartile ₄ vsquartile ₁ = 1.31 (95% confidence interval (CI) = 1.13, 1.53)), and an indirect relation mediated by BMI status (1.01 (95% CI: 1.01, 1.02)), accounting for 5% of the total relation.

CONCLUSION

These results indicate that high dietary quality may contribute to the preservation of overall health during aging, partly via obesity prevention and partly via other mechanisms.