Losing weight improves sperm quality – but only if the weight loss is maintained

Health and Wellness 11. aug 2022 2 min Professor MSO Signe Sørensen Torekov Written by Kristian Sjøgren

Men with obesity can double their sperm count if they lose weight and maintain the weight loss. This may be one more potential opportunity for men who are struggling with their fertility, says a researcher.

Obesity negatively affects men’s sperm quality, but new research shows that men with obesity can improve sperm quality by losing weight.

Weight loss quickly improves sperm quality, with the sperm count increasing by up to 100% with maintained weight loss. An increasing number of sperm may increase the chances of achieving pregnancy with a partner.

“Weight loss was very clearly associated with improved sperm quality, and this may be good news for some couples who are struggling to become pregnant. If the low sperm count is one of the reasons the couples are struggling, this study may add more opportunities to improve this,” says a researcher behind the study, Signe Torekov Sørensen, Professor at the Department of Biomedical Science of the University of Copenhagen.

The research results have been published in Human Reproduction.

Semen samples from 56 men

The study is part of a major study of methods for maintaining weight loss involving 215 people with obesity in Denmark. They lost about 12% of their weight through a low-calorie diet and were then randomised to different interventions to maintain the weight loss.

All groups received general guidance according to the recommendations on healthy weight of Denmark’s health authorities.

  • One group received placebo.
  • The second group had exercise training and placebo.
  • The third group received a GLP-1 receptor agonist.
  • The fourth group had exercise training and a GLP-1 receptor agonist.

The major study showed that exercise training or drug treatment enables weight loss to be maintained, and combining exercise and drug treatment led to additional weight loss.

Of the 215 participants, 56 men supplied semen samples. Of these, 37 supplied three sperm samples; one when the trial started, one just after losing weight and one after 1 year in the weight maintenance phase.

“This was one of the first randomised controlled trials of its kind to examine how weight loss affects sperm quality. In addition, the participants lost relatively more weight, and the few previous similar studies have had far fewer participants or considerably less weight loss,” says Signe Torekov Sørensen.

Sperm count doubled after 1 year

This study showed that weight loss can improve sperm quality.

Immediately after the participants lost weight, the number of sperm increased by 40% on average.

The participants who maintained the weight loss after 1 year had 100% more sperm, but the participants who regained weight after the intervention showed no improvement.

“We found that men with obesity can improve sperm quality by losing weight. Other studies have shown that increased sperm count reduces the time to pregnancy, so our findings could indicate that weight loss may increase the pregnancy rate,” explains Signe Torekov Sørensen.

Benefits arrive early

Signe Torekov Sørensen says that the effect of losing weight on sperm quality happens early: sperm quality improved by 40% after 8 weeks of weight loss.

She also says that men struggling with reduced sperm quality and overweight may now have a new way to improve their fertility.

“Many factors affect the quality of sperm, including genetic factors, and smoking also reduces it. The results provide an additional possible way to improve men’s sperm quality,” says Signe Torekov Sørensen.

Signe Sørensen Torekov, M.Sc. Human biology, PhD, is Professor MSO at the Department of Biomedical Sciences, University of Copenhagen, Denmark, and al...

© All rights reserved, Sciencenews 2020