Sedentary behaviour, physical activity and dietary patterns are independently associated with the metabolic syndrome.

AIM This study assessed the independent relationships of daily sitting time, levels of work and leisure-time physical activity (PA), and dietary patterns of patients with the metabolic syndrome (MetS). METHODS This population-based, cross-sectional study included 3090 French subjects aged 35-64 years. Daily time spent sitting and PA levels were assessed by an interview-administered questionnaire, while dietary patterns were identified using the factorial method of principal component analysis. Independent associations of lifestyle behaviours with the MetS were assessed by multivariable logistic-regression models adjusted for age, centre, educational level, smoking status, total calorie intake, heart rate and menopausal status. RESULTS The multivariable-adjusted ORs [95% CI] for MetS in the fourth quartile of sitting time and leisure-time PA were 1.65 [1.11-2.44] (P for trend < 0.01) and 0.58 [0.40-0.84] (P for trend < 0.001), respectively, for men, and 2.35 [1.41-3.92] (P for trend < 0.01) and 0.52 [0.33-0.82] (P for trend < 0.01), respectively, for women. Work PA was not favourably related to the MetS, particularly in women. An 'energy-dense' dietary pattern was independently associated with higher ORs for the MetS in both genders. However, accounting for body mass index (BMI) weakened the associations, which otherwise remained significant for leisure-time PA and the energy-dense dietary pattern in men, suggesting that BMI may be a potential mediator of these relationships. CONCLUSION This study demonstrated a dose-response association between sitting time, an energy-dense dietary pattern and the MetS, together with a graded inverse association between leisure-time PA and the MetS. In addition to the usual advice for PA and healthy eating, limiting the amount of time spent sitting should also be promoted through public-health initiatives.