Reuters reports that an article in the journal Fertility and Sterility in August 2008 suggests that obese men may have more trouble becoming fathers, even if they are otherwise healthy.  Lower hormonal levels, including testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) may account for lower reproductive rates.   Excess body fat is associated with the body’s conversion of testosterone into estrogen, decreasing libido in men and increasing the chance of erectile dysfunction.  The findings suggest that obesity alone is an "infertility factor" in otherwise healthy men, writes Dr. Eric M. Pauli and his colleagues at the Pennsylvania State University College of Medicine in Hershey.