A new research study from the University of Copenhagen shows that obesity affects a man's sperm count, and weight loss can double a man's sperm quality. One study from the Harvard School of Public Health found that overweight and obese men are more likely to have lower sperm counts and sometimes produce no sperm at all. 

Findings on How Obesity Affects a Man's Sperm Count

The researchers at Harvard School of Public Health combined 14 studies that analyzed sperm count in overweight and obese men compared to normal-weight men. They found that overweight men were 11% more likely to have a low sperm count while obese men were 42% more likely. Similarly, overweight men were 39% more likely not to produce sperm, and obese men were 81% more likely. 

In the study produced by researchers at the University of Copenhagen, 56 men between the age of 18 and 65 participated. Men who lost an average of 36 pounds showed an increase in sperm concentration by 50% and sperm count by 40%, given the sustained weight loss. "[For] the men who maintained the weight loss: after a year, these men had twice as many sperm cells as before their weight loss. The men who regained weight, lost the improvements in semen quality," Professor Signe Torekov says.

Aside from how obesity affects a man's sperm count, new evidence shows that obesity may also impact sperm quality. A study published in the National Library of Medicine found that obesity in men can impair their child's metabolic and reproductive health, thus suggesting that a father's health is transmitted to the children through the sperm. 

"Interestingly, the molecular profile of germ cells in the testes and sperm from obese males is altered with changes to epigenetic modifiers."

How Obesity Affects a Man's Fertility

It has been demonstrated that obesity impacts a woman's fertility due to several factors, including the impact obesity has on menstruation, ovulation, and the increased likelihood of developing PCOS. Yet, only recently are researchers beginning to understand how obesity affects a man's fertility. 

As discussed above, obesity affects a man's sperm count, which makes the likelihood of conception more difficult. In couples with an overweight or obese male and a normal-weight female, there are higher incidences of increased conception time compared to male/female couples at a normal weight. 

Similar to the impact obesity has on a woman's fertility, it is understood that there are also hormonal issues at play in obese men, which affects fertility. However, physicians and researchers are still trying to understand the exact mechanisms that affect fertility and how obesity affects a man's sperm count. It has not yet been determined if obesity directly causes a low sperm count or if it is a result of the associated health conditions that come with being overweight. 

How to Reverse The Effects of Obesity on Male Fertility 

With mounting evidence highlighting how obesity in men negatively impacts fertility and lowers sperm count, physicians and patients are seeking solutions to mitigate male infertility worldwide. As discovered in the research study at the University of Copenhagen, prolonged weight loss can improve a man's sperm count and sperm quality by 40 to 50 percent. 

For men suffering from obesity (BMI 30+) or morbid obesity (BMI 35+), bariatric surgery may be an excellent choice to improve fertility and sperm count. Bariatric surgery can help patients lose up to 100% of their excess weight and better manage their health conditions, if not cure their comorbidities for good. With a reduction in weight and improved health, men can experience faster conception rates and lower their child's risk of developing metabolic or reproductive health issues.