Prepubertal cyclicity in feeding behavior and body weight regulation in the female rat

Periodic alterations in feeding behavior were observed in the weanling female rat between 21 and 50 days of age. Systematic changes were detected by spectral analysis in total eating time, number of meals, meal duration and body weight gain, and were found to be related to the occurrence of vaginal opening (VO) and the subsequent vaginal cycle. Although periodic alterations in food intake per 100 g body weight and meal size occurred prior to puberty, no consistent changes in these parameters were noted on the day of VO or at the first proestrus period. While ovariectomy at 21 days of age did not affect the steady increase in either food intake or body weight before puberty, it did abolish the periodic changes noted in relative food intake and body weight gain during this period. These data suggest the importance of ovarian hormones in generating prepubertal 4-day cyclicity in feeding behavior.