Usual dietary isoflavone intake and body composition in postmenopausal women

Previous studies suggest an association between isoflavone supplementation and improved body composition. The purpose of this study was to investigate the cross-sectional association between isoflavone consumption from a typical Western diet and measures of total body fat, body fat distribution and lean body mass.

This study examined 208 healthy, postmenopausal women, aged 45 to 74 years. At screening, demographic and behavioral characteristics and medical history were obtained. One month later, dietary intake for the past year was assessed with a standardized questionnaire. Anthropometric measurements were obtained, and bioelectric impedance was used to measure total body fat (lb) and lean body mass (lb). Isoflavone consumption did not vary by age, smoking, exercise, or daily alcohol intake.

A significant inverse relation was shown between genistein consumption and weight, body mass index, waist circumference, and total body fat mass by bioelectric impedance analysis (P < 0.05). These findings remained significant after adjustment for potential confounders. No association was seen, however, between genistein, daidzein, or total isoflavone intake and body fat distribution or lean body mass.

This study suggests that usual dietary isoflavone intake is associated with reduced total body fat and may consequently have a role in the prevention of chronic disease.