Body mass index is a major determinant of abdominal fat accumulation in pre-, peri- and post-menopausal women.

Objective: To investigate the role of menopause, body mass index (BMI) and aging on body fat distribution in women.

Design: In this population-based cross-sectional study, 335 women (126 in pre-menopause, 75 in peri-menopause and 134 in post-menopause according to Stages of Reproductive Aging Workshop criteria) were evaluated for body mass composition and fat distribution by dual X-ray absorptiometry procedure. A sub-group of 79 women with similar age and BMI was extracted from the sample to examine the relative influence of BMI in body fat distribution.

Results: ANCOVA analysis of total sample showed an age-independent increase of total fat mass (p < 0.001) and percentage on total weight (p < 0.001), arms fat mass (p < 0.01), legs fat mass percentage on total fat (p < 0.05) and trunk fat mass (p < 0.001) and percentage (p < 0.05) in peri- and post- with respect to pre-menopausal women. In the sub-sample including age and BMI matched women the difference of regional fat parameters among menopausal status was no more statistically significant.

Conclusion: BMI, and not age, is the main determinant of the increase of body fat mass (total and abdominal) observed during the menopausal transition.