Associations between dietary intake and body fat independent of genetic and familial environmental background.

Objective: To determine whether habitual dietary intake was associated with body fat mass and body fat distribution, independently of possible confounding by the genetic and shared environmental background.

Design And Subjects: We examined correlations between intrapair differences in specific dietary composition and intake of foods and macronutrients in relation to differences in anthropometric phenotypes in a population-based sample of monozygotic twins. Data originated from a cross-sectional study, conducted in 1997-2000, of healthy twin pairs with measured anthropometry and information from food frequency questionnaire supplemented by self-reported weight from 1994 to 2002 and self-reported waist circumference from 2002. For this study, 153 men and 158 women identical twin pairs were included. Intrapair differences in dietary factors and anthropometry were studied using correlation analyses.

Results: Only few statistically significant correlations between intrapair differences in dietary intake and anthropometry were found. Consistent positive associations were found between intake of sugar-sweetened soft drinks and body fat in men, but not in women. Intake of vegetable oil was inversely associated with waist change in men. Only the latter finding remained significant when accounting for multiple testing.

Conclusion: Only few associations between individually modifiable dietary factors and body fat measures were found, and only among men. Intake of vegetable oil was inversely related to waist change and intake of sugar-sweetened soft drinks was directly related to body fat in men.