The Impact of Obesity on Fertility in Men

The challenges women with obesity face when trying to become pregnant are well-documented. However, the impact of male obesity related to fertility is less frequently discussed, even though nearly three out of four men have obesity. Complicating matters further, research has identified another uncontrollable risk for men: sons born to overweight mothers (BMI> 25kg/m²) have higher odds of infertility compared to sons born to mothers of a healthy weight. This makes it all the more important for adults with obesity to manage their weight, especially when considering pregnancy.

Factors Contributing to Male Infertility

There are several ways obesity affects male fertility.

Erectile Dysfunction

Although Erectile Dysfunction (ED) is not a direct cause of infertility, both conditions share many root causes. Further, several characteristics of obesity, including physical inactivity, insulin resistance, hormonal imbalances and psychological issues, contribute to a higher risk of  ED. Obesity also is an independent risk factor for ED, and among men who experience it, 79 percent — or about eight million men in the United States — are obese. ED also can lead to a decreased sexual desire.

Decreased Sperm Count

The most common causes of infertility are related to problems with the testicles where sperm is produced and stored. Men with obesity are 42 percent more likely to have a low sperm count and 81 percent more likely to produce no sperm. Sperm in men with obesity also is affected by a high BMI and excess leptin, which further contributes to infertility.¹ Obesity can contribute to:

• Decreased sperm counts
• Lower motility
• Increased sperm DNA fragmentation
• Lower testosterone levels
• Higher estradiol and luteinizing hormone levels

Change in Semen Parameters

Semen quality deteriorates as men age, which contributes to infertility. In the event that fertilization occurs, the inferior quality of sperm contributes to a greater risk of miscarriage.

Diabetic Risk

Men who are obese have decreased Sex Hormone-Binding Globulin (SHBG) and androgen levels, which can affect sperm maturation. SHBG is further inhibited as a result of higher insulin levels associated with obesity. If it becomes too low, testosterone converts to estrogen and can create a hormonal imbalance that causes infertility. Men with obesity and diabetes also have greater levels of DNA damage.²

Pre-Conception Weight Loss via a Very Low Calorie Diet

Pre-conception weight loss is the recommended course of action for both men and women seeking to conceive. Men are less likely to seek health care or to join a weight loss program, so it is important that weight loss recommendations consider this and other lifestyle variables. A Very Low Calorie Diet (VLCD) is efficacious, convenient, and quick and easy to prepare. And, because they are effective for both men and women, couples trying to conceive can follow the same program and provide support for one another as they try to grow their family.

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Sources:

1. Leptin and its Actions on Reproduction in Males
2.  Diabetes-induced Hyperglycemia Impairs Male Reproductive Function: A Systematic Review

About the Author: Dr. Andrea Pampaloni has over 20 years of communication experience across corporate, academic, nonprofit and government sectors. She provides research and writing services on a range of business issues and industry-specific topics to prepare white papers, articles, proposals, presentations, technical content, and speaking points, as well as marketing-communications content such as blogs, website content, newsletters, news releases and award submissions. Dr. Pampaloni’s research findings have been presented at national and international conferences and published in peer-reviewed journals, and she is a ghostwriter for three books, a Forbes article, and several corporate blogs.