Combined diet and exercise intervention reverses the metabolic syndrome in middle-aged males: results from the Oslo Diet and Exercise Study

We examined the single and combined effects of a 1-year diet and exercise intervention on the International Diabetes Federation (IDF) metabolic syndrome among middle-aged males. The study was a randomized, controlled, 2 x 2 factorial intervention study. Participants included 137 men with metabolic syndrome according to the IDF criteria aged 40-49 years randomly allocated to four intervention groups: diet alone (n=34), exercise alone (n=34), the combination of the diet and exercise intervention (n=43) or control (n=26). The main outcome measure was metabolic syndrome as defined by IDF criteria (2005). In the combined diet and exercise group, 14 participants (32.6%) (P < 0.0001 as compared with control) had the metabolic syndrome after 1-year intervention. In the diet-only group, 22 participants (64.7%) (P=0.023 vs control) and in the exercise-only group 26 participants (76.5%) (P=0.23 vs control) had the metabolic syndrome following the intervention. Utilizing the factorial design, both dietary and exercise intervention had significant effects (P < 0.005) on the resolution of the metabolic syndrome. Both exercise and dietary intervention reduced metabolic syndrome prevalence compared with control after 1 year of intervention. However, the combined diet and exercise intervention was significantly more effective than diet or exercise alone in the treatment of the metabolic syndrome.