How Obesity Can Affect Male Fertility

Posted on by Paul Turek, MD

You have often heard me say that sperm production is an engine that really wants to run hard and fast. And, that by not taking great care of yourself, sperm quality and fertility can suffer. Given that 1 in 3 Americans have it, one of the biggest elephants in the room is obesity. Now, the literature is oozing with new data that puts real live numbers to the obesity and fertility problem.

Obesity and Sperm

As discussed before in this forum, there appears to be a direct relationship between a man’s weight and not only his semen quality but also his fertility.

Men who are overweight or obese — as measured by Body Mass Index or BMI, which looks at weight in relation to height — are more likely to have lower semen volumes, less sperm and worse sperm quality than men who maintain a normal BMI.

Being overweight or obese can interrupt a man’s hormonal balance. An increase in adipose, or fat, tissue has been linked to an increase in an enzyme that converts testosterone (the male sex hormone) to estrogen (the female sex hormone). Higher-than-normal estrogen levels cause sperm production to suffer.

Another problem with excess body fat is that the extra “insulation” can cause the testes to overheat, to the detriment of sperm production.

Indirectly, being overweight can affect a man’s sex drive and make him less interested in sex.

The combination of these factors can make it quite difficult to conceive naturally.

A brand new study out of Paris has now put more meat on this bone. In this meta-analysis of 14 prior studies and 10,000 subjects, new facts were put forth on the obesity and infertility issue. Here they are in a nutshell:

  • Obese men are 42% more likely to have low sperm counts than men of normal weight.
  • Obese men are 81% more likely to be sterile (have no ejaculated sperm) than men of normal weight
  • For every 20 pound increase in a man’s weight there is a 10% increase in the chance of infertility

Is that enough fodder to make the changes you need to make? If not, then read on.

Fat and Male Fertility

Clearly, a large chunk of the obesity problem is related to diet. Junk in means waistlines out. In the first study of its kind published last week, researchers from Harvard collected semen samples from 99 mostly (71%) overweight or obese infertile men and assessed the fat intake in their diets over the previous year. Here is what they found:

  • Eating a lot of saturated fats was associated with lower sperm counts
  • Eating omega-3 polyunsaturated fats — the fats commonly found in fish and plant oils — was associated with better quality sperm

Of course complicating the study is the fact that most of the men were obese and all of them were infertile. Although the study included weight in the analysis, they did not consider conditions such as diabetes, heart disease, cholesterol issues and sedentary lifestyle that are associated with being overweight. Ultimately, such “details” have been known to kill a study over time. Regardless, dietary fats are now key suspects in the link between obesity and infertility. In other words, sperm are feeling the weight of obesity.

Now What?

As a men’s health specialist, I am always searching for lifestyle changes that can improve male fertility and health. As you can imagine, I was ecstatic to publish the first paper linking hot baths to lower sperm counts, as this identified an easily modifiable lifestyle issue: just say no to tubs! Well, here, my friends, is another one: Losing weight and eating well. This is a good thing! Maybe not as easy to fix as getting out of tubs, but one that is also much more germane to a long and prosperous life. So try The Turek Clinic Weight Control Plan. I have heard nothing but good feedback.