The prevalence of obesity has increased in children over the past few decades. Approximately 20% of adolescent boys are now considered obese. It is well accepted that obese children are at increased risk for high blood pressure, lipid abnormalities and type 2 diabetes. Recent studies have uncovered yet another undesirable effect of obesity. The testosterone levels of obese boys are only half those of lean boys at completion of puberty. Testosterone is important for muscle and bone development. Men with low testosterone are at higher risk of insulin resistance and inflammation, which lead to type 2 diabetes and heart disease. Since testosterone is the major reproductive hormone, these obese boys are at risk of decreased fertility. Men are supposed to achieve their peak testosterone levels at puberty. Thereafter, there is a decline in testosterone levels at the rate of 2% per year for the rest of life. Thus there is a clear need to develop a deeper understanding of low testosterone in these males who are entering their peak fertility years. There are no approved treatments for this disorder. The investigators propose to conduct a randomized placebo controlled trial to evaluate the effect of treatment with clomiphene in obese boys and young men(age 16-21 years) who have low testosterone concentrations. Clomiphene is a drug that increases testosterone concentrations and possibly increases sperm production. In contrast, testosterone replacement therapy decreased fertility and cannot be used in young men. Investigators will study the effect of treatment with clomiphene or placebo tablets for 12 weeks in 30 subjects. The study will evaluate:-