Background/objectives: The relationship between diet quality and development of obesity is complex and unresolved. The aim of this study was to assess and compare the predictive value of six different dietary scores on both relative weight change and the risk of obesity after 13 years of follow-up in adults aged 45 years and older.
Subjects/methods: Six scores reflecting adherence to different nutritional recommendations (the French Programme National Nutrition Santé-Guideline Score (PNNS-GS), the Dietary Guidelines for Americans Index (DGAI), the Diet Quality Index-International (DQI-I), the Mediterranean Diet Scale (MDS), the relative Mediterranean Diet Score (rMED) and the Mediterranean Style Dietary Pattern Score (MSDPS)) were estimated in 3151 participants in the French SU.VI.MAX (SUpplémentation en VItamines et Minéraux AntioXydants) study. Associations of dietary scores with 13-year weight change were assessed through multivariate linear regression models, and obesity risk was analyzed with logistic regression, providing odds ratios (OR) and 95% confidence intervals (CI).
Results: Except for the MSDPS, higher scores, that is, better adherence to nutritional guidelines or to a Mediterranean diet, were associated with lower weight gain in men (all P-value for trend <0.05). In addition, among men, ORs for becoming obese after 13 years associated with a 1 s.d. increase in dietary scores ranged from 0.63, 95% CI: 0.51, 0.78 for DGAI to 0.72, 95% CI: 0.59, 0.88 for MDS. These associations were weaker or not statistically significant in women.
Conclusion: Overall, the six dietary scores predicted obesity risk equally well. Among French adults, strong adherence to dietary guidelines appears to be protective with regard to weight gain and obesity, especially in men.