Physical activity and energy intake selectively predict the waist-to-hip ratio in men but not in women.

BACKGROUND: The waist-to-hip ratio (WHR) has emerged as an important risk factor for several chronic diseases, but little quantitative information exists about its relation with energy intake and expenditure in men and women.

OBJECTIVE: We examined the relative role of energy intake and physical activity as determinants of WHRs in men and women, after adjustment for body mass index (BMI) and other likely confounding factors.

DESIGN: In the context of the European Prospective Investigation into Cancer and Nutrition (EPIC), 16433 women and 11520 men aged 30-82 y, apparently healthy and from all over Greece, were examined between 1994 and 1999. Anthropometric measurements were taken, a validated semiquantitative food-frequency questionnaire was administered, and time-weighted occupational and leisure activities were assessed. The WHR was regressed, separately for men and women, on energy intake and energy expenditure after age and BMI were controlled for.

RESULTS: Results for women and men differed. In women, neither energy intake nor energy expenditure was associated with the WHR in any way other than that mediated through BMI. In contrast, in men, higher energy intakes and higher energy expenditures were associated significantly, and largely independently of BMI, with higher and lower WHRs, respectively.

CONCLUSIONS: Because the WHR is an important predictor of several cardiovascular and other chronic diseases, documentation of a strong effect of physical activity on the WHR selectively in men may provide a partial explanation of how the effect of physical activity is mediated and why physical activity is more effective in men than in women in reducing disease risk.