Does weight loss improve semen quality and reproductive hormones? Results from a cohort of severely obese men. That’s the title of the research article I recently read.
And I learned a new word today – subfecundity.
In this research about how weight loss affects male fertility the authors said “Male obesity has been linked to subfecundity and a dose-response relationship between increasing BMI and subfecundity has been proposed.”
So I thought “What the heck is subfecundity?” Basically it just means subfertility. Okay, got it.
So does body mass index (BMI) correlate to male fertility?
44 men with a median age of 32 were enrolled in a 14-week weight-loss program. The median starting BMI was 44. Wow, so these men were mostly morbidly obese. Obese is when you have a BMI of 30 or greater and morbidly obese is when your BMI is 40 or greater.
Of the 44 who started 27 actually participated in the post-weight loss followup. So this wasn’t a huge study but it’s a pilot and still worth a look.
Before and after the weight loss program, the participants had blood samples drawn, provided semen samples and had clinical examinations.
Being a part of a research study isn’t always the most glamorous of endeavors. “The participants were asked to provide the semen sample by masturbating into a plastic container after at least 48 hours of sexual abstinence. They were instructed to keep the container close to the body, during transportation to the mobile laboratory on the weight loss centre to avoid cooling, and one trained medical laboratory technician performed all initial semen analyses within one hour after collection.”
The authors were able to determine “After adjustment for potential confounders, BMI was inversely associated with sperm concentration, total sperm count, normal sperm morphology, and motile sperm.”
This essentially means that as BMI went up (more obese men) sperm concentration, total sperm count, normal sperm shape, size and activity went down. Another “bonus” for the morbidly-obese men was their total testosterone was lower (not good) and their estradiol (female hormone) was higher (not good).
Lower testosterone is not good for a variety of reasons. To name a few men who have low testosterone have an increased chance of alzheimers, less mental acuity, increased depression, low sex drive, erectile dysfunction, mood problems, fatigue, sleep disturbances, increased body fat, less muscle mass and lower ability to acquire muscle mass through training. And as the authors of this study state “… testosterone is required in large concentrations to maintain spermatogenesis.” In other words, to create new sperm we need testosterone!
So what happened? Well, the average weight loss was about 15 percent of their body weight. So a 300-pound man lost about 45 pounds in 14 weeks. I say “Nice job!” to the guys for their efforts that’s for sure.
The authors stated “Weight loss was positively associated with an increase in total sperm count and semen volume. “Additionally, the percentage weight loss was associated with an increase in testosterone…”
As always the authors were cautious not to say their study was the end-all be-all. They know it’s not. But overall this study adds more weight to a good deal of other research which supports the general outcome of increased testosterone and improved fecundity (Good! I got to use part of the word again!) when morbidly obese men engage in significant and sustained weight loss.
Guys? It’s just one more reason to shed those extra fat pounds if you’re in the chase to become a Father or you want to actually feel like and be all the man you were meant to be.
Here’s a link to the complete study
Click For Full Study