Fig. 3.

Dietary energy restriction disrupts reproductive physiology in females. Panel A, The ability of female Sprague Dawley rats to perform a 4-d estrous cycle was assessed in the presence of the four dietary alteration paradigms. Irregular estrous cycling represents cycles with between 1 and 3 altered days in the pattern. Nonestrous cycle animals displayed no regularity during their typical 4-d cycle. Percentage distribution of animal numbers per cycling group are represented. Statistical significance of the relative values were calculated relative to the control proportions using a Student's t test. Panels B–D, Plasma levels of estradiol (panel B), testosterone (panel C), and corticosterone (panel D) in male and female rats that had been maintained on the indicated diets. C, Control. *, P < 0.05; **, P < 0.01; ***, P < 0.001.