[Influence of abnormal weight and imbalanced diet on female fertility]

The cult of a slim body without the slightest bit of adipose tissue and the food restriction or selection habits it creates are extremely common in our society. Their influence on menstrual cycle and female infertility is not negligible. A vegetarian low calorie diet may induce cycle disorders and a short luteal phase. Disturbances in the pulsatility of gonadotropic hormones are responsible for anovulation, and they occur when slimness with excessive reduction of the body fat mass is associated with psycho-socio-professional stress factors or with intensive sporting activities. The greater frequency of dysovulation in obese women, notably those who put on weight rapidly, is accompanied by numerous hormonal changes, including reduced sex hormone-binding globulin, increased ovarian and adrenal androgen production, increased peripheral aromatization of androgens to oestrogens, and altered gonadotropin pulsatile secretion. The hyperinsulinism consecutive to insulin resistance in obese subjects might act as co-factor of the luteinizing hormone and as such participate in abnormalities of follicular maturation by stimulating the insulin-like growth factor and the ovarian androgens. However, the relative importance of these various factors in the physiopathology of abnormal ovulation remains to be determined. Overweight reduces the effectiveness of clomiphene citrate, menopausal gonadotropins and gonadotropin-releasing hormone in stimulating the follicles. Weight loss reduces hormonal disturbances and facilitates follicular maturation and ovulation in spontaneous or induced cycles.