Contribution of lifestyle factors to educational differences in abdominal obesity among the adult population.

OBJECTIVE
This is the first study to systematically examine the behavioral factors that may explain the inverse association between education and abdominal obesity in adults.

METHODS
Cross-sectional study conducted among 3541 men and 3564 women representative of the population aged 25-64 years in Spain. Abdominal obesity was defined as waist circumference >102 cm in men and >88 cm in women. Analyzes were performed with logistic regression, with progressive adjustment for obesity-related behaviors.

RESULTS
The age-, sex- and town size-adjusted odds ratios for abdominal obesity were 1.69 in men and 1.85 in women among individuals with lowest versus highest education. After adjustment for all the studied behaviors, the odds ratio was reduced to 1.49 in men and to 1.45 in women. The factors with the largest contribution to the higher prevalence of abdominal obesity in individuals with lowest versus highest education were more time spent watching TV and less time spent in exercising, as well as a higher energy intake in women. Tobacco and alcohol consumption, physical activity at home, leisure walking, sedentary behaviors other than TV watching, and sleep duration did not explain the educational gradient in abdominal obesity.

CONCLUSIONS
Watching TV, physical exercise and energy intake explain a substantial part of the inverse association between education and abdominal obesity.