According to one study conducted by University of Buffalo researchers, obese men experience as much as a 40% drop in testosterone production, and that has direct, decidedly negative implications for sexual performance.

FORBES: Sorry, You Can't Sex Yourself Thin (But You Can Kill Your Sex Life with Fat)

Unfortunately, this statistic cuts like a knife the other way as well: research also shows that low testosterone in men is linked to weight gain, Type 2 diabetes and cardiovascular disease (along with poor sexual performance).

FORBES: Sorry, You Can't Sex Yourself Thin (But You Can Kill Your Sex Life with Fat)

Presiley Baxendale QC, appearing for the Health Secretary, said worldwide publicity about the Viagra had led to fears that doctors would come under huge pressure to prescribe the drug, particularly as it has been suggested it could enhance sexual performance.

BBC: Viagra 'limited to cut cost'