| Abstrakt: |
The present experiment tested the hypothesis that 22% body fat based on the Mellits and Cheek (1970) regression equation is a minimum or ‘trigger’ level of fatness required to maintain regularity of menstrual cycles. The validity of the regression equation was cross-validated against densitometric estimates of body fat in 30 athletes (track, gymnastic, crew) and 30 non-athletes who were below 22% fat. For the total sample, the validity correlation was r = 0·47 between body fat (density) and body fat (regression equation); it was r = 0·75 for athletes and r = 0·47 for non-athletes. For all subjects, 60% had regular menses, 27% were oligomenorrheic and 13% were amenorrheic. The lowest body fat (density) was 12·8% for an athlete with a regular cycle and 12·2% for an oligomenorrheic athlete. The results show that: (1) the Mellits and Cheek (1970) height-weight based regression equation to determine fatness is not valid for women below 22% fat, and (2) 13% body fat (not 22%), should be considered an upper-bound estimate of a minimum level of fatness associated with normal ovulatory cycles. |
