Obesity is linked to infertility in men

Men with increased body mass index are significantly more likely to be infertile than are normal-weight men, according to research conducted at the National Institute of Environmental Health Sciences and published in Epidemiology (2006; 17:520-3).

“The data suggest that a 20-pound increase in men’s weight may increase the chance of infertility by about 10%,” said Markku Sallmen, PhD, lead author, who is now at the Finnish Institute of Occupational Health.

The researchers studied couples enrolled in the Agricultural Health Study, a large project that began in 1993 to examine factors that affect the health of farmers and their families. The team divided the couples into infertile (couples who tried for more than 1 year to conceive) and fertile groups. Researchers found that men’s body mass index was an independent risk factor for fertility, and after adjustments for other factors that could affect fertility, there was a nearly two-fold increase in infertility among obese men.