A University of Adelaide review found that compared to men of a healthy weight, obese men were more likely to be infertile, unsuccessful with assisted reproduction and have poor quality DNA in their sperm.

Dr Jared Campbell, from the University of Adelaide’s Joanna Briggs Institute, led a review involving 30 research papers about obesity and male fertility, and more than 115,000 participants.

The review, published in the journal Reproductive BioMedicine Online, found that as with women, obesity has serious implications for fertility in men.

“Health and wellbeing is often considered to only be an issue for women when it comes to starting a family but this review has found strong evidence that obesity in men negatively affects reproductive potential,” says Dr Campbell.

“Our study found that compared to men of a healthy weight, obese men were two-thirds more likely to be infertile and almost three times as likely to have a non-viable pregnancy after undergoing assisted reproduction.

“It looks like DNA fragmentation and low metabolic activity in the sperm could be responsible,” he says.

Dr Campbell says that this review sets out to provide clarity in the field of paternal obesity.

“There is a lot of research being conducted about the impact of maternal obesity on fertility and the health of offspring but far less on the impact of paternal weight, and some existing studies were conflicting,” says Dr Campbell.

“The role of this review was to pull together all existing research that looked at males that were obese and their fertility, and provide a pooled summary of the findings,” he says.

Dr Michelle Lane, from the University of Adelaide’s Robinson Research Institute, says this review supports the vital health message that both men and women should be a healthy weight before trying to conceive a child.

“Men often get let off the hook when it comes to infertility, with women feeling at fault, but this review clearly demonstrates the importance of men’s health in reproduction and pregnancy,” says Dr Lane.

“I’d encourage both men and women to aim for a healthy weight and diet before trying to conceive a child,” she says.