The purpose of this study is to examine how obesity and weight loss following bariatric surgery affect reproductive function. The study is particularly interested in how changes in hormones (those produced in the stomach and fat tissue) following weight loss affect reproductive function. Specifically, we, the researchers at Penn State University, propose to characterize reproductive abnormalities in morbidly obese men and women. We hypothesize that morbid obesity leads to reproductive abnormalities in men and women. We plan to examine the short-term effects of alteration in GI hormones after bariatric surgery on reproductive function. We hypothesize that bariatric surgery radically alters GI hormone expression, resulting in immediate changes to the hypothalamic-pituitary-gonadal axis in men and women. Lastly, we, the researchers, plan to examine the long-term effects of weight loss and changes in adipokines on reproductive function. We hypothesize that the changes in adipokine levels resulting from fat mass reduction lead to substantial long-term improvements in reproductive function and fertility. We also hypothesize that there are sexual dimorphisms in adipokine levels following weight loss, with women experiencing larger changes than men.