Hi and thanks for the query, It s bothersome obtaining absent periods, especially in a female who has had normal cycle for over a year. It s quite reasonable to put the absence or missed periods to be due to stress of change of diet / exercise as causes of this absence of missed periods. However, other serious medical conditions must be considered. An abdominal ultrasound should be done to exclude Polycystic ovarian disease. Use of hormonal therapy under these circumstances is justified, provided other organic causes are not identified. I suggest the child be keenly followed up by a gynecologist. Thanks and kind regards. Bain LE, MD.