collecting daily urine specimens over the course of a menstrual cycle and measuring ovarian hormones. The researchers were surprised to find that ovulation rates remained high (more than 90 percent at all time points before surgery and at one, three, six, 12 and 24 months after surgery). The quality of the ovulation also remained unchanged, and there was little effect on the ovarian cycle. The exception is a notable shortening of eight to nine days of the follicular phase. The follicular phase is the first half of the menstrual cycle, from the end of the previous menstrual flow until the release of the egg (ovulation). Three months after surgery, the phase is six-and-a-half days shorter, and then up to nine days shorter by 24 months post-surgery. Obesity is associated with longer menstrual cycles, specifically because of an increase in the follicular phase. The reason the phase shortens with weight loss is not yet known. Sexual function at one year as detected by the Female Sexual Function Index, a self-reporting index of sexual health collected through questionnaires, is most noticeable. This improvement is independent of changes in hormone levels and body composition. Sexual desire and arousal increase the most. Researchers did not track sexual activity or desire to conceive. However, increased sexual desire may have led to increased frequency of sexual activity. "The effects of weight loss on reproductive function are more modest than we hypothesized. In terms of ovulation, there doesn't appear to be a window after surgery where fertility