Diet or exercise: what is more effective in preventing or reducing metabolic alterations?

Objective/design: The influence of diet and exercise on metabolic syndrome is controversial since fit individuals might also eat healthier foods. We evaluated the association of diet/exercise variation with reductions in metabolic variables and C-reactive protein (CRP) values in the experimental and control arms of a 1-year randomized lifestyle intervention trial performed in patients with multiple metabolic abnormalities. Methods: A prospective study of 169 cases and 166 controls after a lifestyle intervention was performed. Results: In the intervention group, 15/169 (8.9%), 63/169 (37.3%), 70/169 (41.4%) reached only dietary, only exercise, dietary/exercise targets, respectively. Reductions in weight, BMI, and waist were significant only in patients who increased exercise. Most controls did not reach any target (131/166, 78.9%), while only few patients reached only dietary (13/166, 7.8%), only exercise (5/166, 3.0%), and dietary/exercise targets (17/166, 10.2%). Weight, BMI, and waist reduction was more pronounced in those reaching the exercise target. In the whole cohort, increased exercise was inversely associated with weight, BMI, waist, and CRP, increased saturated fat was directly associated with weight, BMI, waist, and diastolic pressure variations, while increased fiber intake was inversely associated with glucose values in a multiple regression model. After adjusting for waist changes, the associations between exercise and CRP (beta= -0.023; 95%CI -0.028 -0.017;p<0.001) and the associations between fiber and glucose (beta= -0.022;-0.031 -0.013;p<0.001) remained significant. Conclusions: Independent of weight reduction, exercise level and fiber intake are inversely associated with CRP, and fasting glucose values, respectively. Change in lifestyle may lower inflammation and prevent metabolic deterioration.