Changes in fat distribution (WHR) and body weight across the menstrual cycle.

The aim of the present study was to analyze changes of the body weight and waist-to-hip ratio during menstrual cycle, with special respect to changes around ovulation. 32 healthy young women ranging in age between 19 and 30 years (X = 23.5) were enrolled in the study. Beside a basal anthropometric investigation (stature, weight, BMI, waist circumference, hip circumference, fat percentage, waist to hip ratio) the probands were instructed to take body weight, waist and hip circumference and basal body temperature every morning by themselves over a whole cycle. Three proband groups according to cycle length (average, short and long) were defined and eight hormonal contraceptive users served as controls. It turned out that body weight increased only slightly during the second cycle half in all proband groups. A marked decrease of WHR around the time of ovulation was found in the proband group who exhibited average cycle length and a successful ovulation could be assumed. Evolutionary and physiological explanations are discussed.