Men who are seriously overweight and undergoing infertility treatment may be more likely to father a child if they lose weight, experts believe.
A study at the University of Aberdeen found that men with a higher body mass index (BMI) had lower volumes of seminal fluid and a higher proportion of abnormal sperm than men with a healthy weight.
The team analysed 5,316 men who were undergoing infertility treatment and found that those with a high BMI were likely to face even greater difficulties in conceiving.
Dr A Ghiyath Shayeb, who presented the findings at the annual meeting of the European Society of Human Reproduction and Embryology, noted that obesity is already known to affect fertility in women.
"Our findings were quite independent of any other factors and seem to suggest that men who are trying for a baby with their partners should first try to achieve an ideal body weight," Dr Shayeb revealed.
The expert added: "Adopting a healthy lifestyle, a balanced diet and regular exercise will, in the vast majority of cases, lead to a normal BMI."