Diet, fitness and metabolic syndrome--the DR's EXTRA study

To study the independent and combined associations of diet and cardiorespiratory fitness with the prevalence of the metabolic syndrome (MetS).

We studied a population-based random sample of 663 men and 671 women 57-78 years of age at baseline of an ongoing randomised controlled trial. Based on a 4-day food record a diet score was created according to goals achieved (vegetables ≥400 g/day, fish ≥2 servings/week, fibre ≥14 g/1000 kcal, saturated fat <10 E%/day). Cardiorespiratory fitness was measured as maximal oxygen uptake (VO(2 max)) in a maximal symptom-limited bicycle ergometer test. MetS was defined by the National Cholesterol Education Program criteria. The lowest prevalence of MetS (5%) was observed among individuals in the highest VO(2 max) tertile and achieving 3-4 dietary goals. The highest prevalence (55%) was observed among those in the lowest VO(2 max) tertile and achieving none of the dietary goals. Among individuals in the highest VO(2 max) tertile, the odds ratio of having MetS was 0.04 (95% CI 0.02-0.10) for those achieving 3-4 dietary goals, 0.07 (0.04-0.14) for those achieving 1-2 dietary goals, and 0.16 (0.07-0.37) for those achieving none of the dietary goals compared with individuals in the lowest VO(2 max) tertile and achieving none of the goals after adjustment for confounding factors.

Healthy diet and higher levels of cardiorespiratory fitness are associated with a reduced risk of having MetS. However, fitness seems to have a stronger association with MetS than diet.