A European Science Foundation report found that mass infertility among European men is caused by a decreased sperm count, which is linked to obesity. At least this time, it's not our fault?
The report mentions that because overweight and obese men tend to produce less testosterone, their sperm is less potent and therefore less likely to successfully impregnate their female partners. The men involved in the study were between 18 and 25 years old, and 40% had sperm counts so low that their best hope for ever successfully reproducing is through in vitro fertilization.
The silver lining here, for those of us who aren't all that keen on the idea of having babies, is to date a fat European man. I'd even go so far as to advise those men with low sperm counts to use that fact to their advantage, as this finding, coupled with the study that concluded that fat men actually have more sexual stamina than their thin counterparts, makes a pretty good case for ignoring social conventions of attractiveness and letting go of any resistance you may have to dating a fat man. After all, he can probably get you off and probably can't get you pregnant.