After the age of 40, there is a gradual decline in the production of testosterone. Among obese men, the decline in testosterone levels is exacerbated by the suppression of the hypothalamic-pituitary-gonadal axis by hyperestrogenemia. The high expression of aromatase enzyme in the adipose tissue enhances the conversion of androgens into estrogens which in turn exert a negative feedback on the hypothalamus and pituitary, leading to the inhibition of production of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle stimulating hormone (FSH), and as a consequence, of testosterone by the testis resulting in hypogonadotropic hypogonadism (HH). Though bone loss is a well recognized side effect of AI in certain populations, such as women with breast cancer, HH obese men present high levels of circulating estrogens that could potentially prevent them from bone loss, estradiol being the main regulator of the male skeleton. This study is designed to determine if aromatase inhibitors in combination with weight loss, compared to weight loss alone, will have a positive effect on muscle strength, symptoms of hypogonadism, and body composition without negatively impacting bone mineral density and bone quality. Results from this study will help determine if certain groups of obese patients would benefit from therapy with aromatase inhibitors.