Although scarce , the data available to date suggest that hyper and rogenism , such as that observed in PCOS , may likely be associated with oligomenorrhoea in exercising women , and may not always represent hypothalamic inhibition secondary to an energy deficiency .
To date , the predominant mechanism underlying  menstrual disturbances in exercising women supports an underlying energy deficiency-related aetiology , in which a failure to compensate dietary intake for the energy cost of exercise suppresses reproductive function .
Increasing evidence demonstrates that energy deficiency plays a causal role in the induction of amenorrhoea in  exercising women , and consistent with this mechanism are findings of glucoregulatory perturbations such as low triiodothyronine , reduced insulin secretion and elevated cortisol , growth hormone and ghrelin levels .
The menstrual disturbance that may differ in its energetic characteristics and , perhaps in its and rogenic and ovarian steroid environment , is oligomenorrhoea .
We conducted a systematic review of the literature to begin to underst and whether oligomenorrhoea in  exercising women is a mild sub clinical phenotype of polycystic ovarian syndrome ( PCOS ) in which exercise is conferring beneficial effects in protecting women from the classic PCOS phenotype , or whether oligomenorrhoea is part of the spectrum of menstrual disturbances caused by an energy deficiency that is often reported in exercising women with menstrual disturbances .
A randomized trial of the effects of two types of short-term hypocaloric diets on weight loss in women with polycystic ovary syndrome.
OBJECTIVE We performed this study as a pilot experiment to investigate the short term effects of two diets of varying composition on weight loss as the primary outcome in obese women with polycystic ovary syndrome ( PCOS ) seeking fertility . DESIGN R and omized clinical trial . SETTING Academic medical center . PATIENT(S ) Thirty-five obese women with PCOS . INTERVENTION(S ) We examined the effects of a 1-month dietary intervention on the PCOS phenotype . Participants were r and omized to one of two energy-restricted diets ; high protein ( HP : 30 % protein , 40 % carbohydrate , and 30 % fat ) or high carbohydrate ( HC : 15 % protein , 55 % carbohydrate , and 30 % fat ) . The fat content was held constant in both diets . MAIN OUTCOME MEASURE(S ) Primary - change in body weight ; Secondary - biometric , hormonal , lipid and lipoprotein , and markers of glucose homeostasis and energy metabolism . RESULT ( S ) Twenty-six women completed the study . Both the HP ( -3.7 + /- 1.9 kg ) and HC ( -4.4 + /- 1.5 kg ) diets result ed in significant weight loss , but there was no significant difference in mean weight loss between the two groups . There were also no differences between diets on a variety of measures including circulating and rogens , measures of glucose metabolism , and leptin . However , the effects of a hypocaloric diet per se on improving metabolic and reproductive abnormalities in a group of PCOS women were marked by a decline in circulating and rogens ( P=.03 ) , fasting and area under the curve ( AUC ) insulins ( P<.05 ) on a 3-hour oral glucose tolerance test ( OGTT ) , and fasting and AUC leptin levels ( P<.0001 ) . There was a high prevalence of menstrual bleeding during the trial ( 14 out of 26 patients ) . CONCLUSION ( S ) Those who completed the short-term hypocaloric diet had a significant weight loss and a significant improvement in their reproductive and metabolic abnormalities . There was no increased benefit to a high-protein diet . Future diet studies evaluating the ideal composition of a hypocaloric diet in women with PCOS will require a large study population , and will most likely require a multicenter trial
Although scarce , the data available to date suggest that hyper and rogenism , such as that observed in PCOS , may likely be associated with oligomenorrhoea in exercising women , and may not always represent hypothalamic inhibition secondary to an energy deficiency .
To date , the predominant mechanism underlying  menstrual disturbances in exercising women supports an underlying energy deficiency-related aetiology , in which a failure to compensate dietary intake for the energy cost of exercise suppresses reproductive function .
Increasing evidence demonstrates that energy deficiency plays a causal role in the induction of amenorrhoea in  exercising women , and consistent with this mechanism are findings of glucoregulatory perturbations such as low triiodothyronine , reduced insulin secretion and elevated cortisol , growth hormone and ghrelin levels .
The menstrual disturbance that may differ in its energetic characteristics and , perhaps in its and rogenic and ovarian steroid environment , is oligomenorrhoea .
We conducted a systematic review of the literature to begin to underst and whether oligomenorrhoea in  exercising women is a mild sub clinical phenotype of polycystic ovarian syndrome ( PCOS ) in which exercise is conferring beneficial effects in protecting women from the classic PCOS phenotype , or whether oligomenorrhoea is part of the spectrum of menstrual disturbances caused by an energy deficiency that is often reported in exercising women with menstrual disturbances .