Is there a link between intermittent fasting and testosterone levels? While many men's health sites make this claim, science has yet to come to an agreement.
What is intermittent fasting?
Intermittent fasting has become a fairly common health and wellness practice. It consists of restricting energy intake to certain periods, so that periods of fasting and normal food consumption alternate within a day or a week. Its health benefits are regularly celebrated and it appears to have a positive effect on hormone levels.
Is there a link between intermittent fasting and testosterone?
Unfortunately, research on the link between intermittent fasting and testosterone has yet to reveal a clear picture. While studies seem to suggest that fasting impacts the process that produces the male hormone, there is still no consensus on whether it increases that hormone or, in fact, decreases it.
One study often cited to support the idea that fasting increases testosterone is from 1989. Nine obese and eight non-obese men were included in the study, which investigated the effect of overnight fasting on luteinizing hormone (LH), a hormone crucial for testicular function and testosterone production. Although no effect was found in obese men, fasting increased LH by 67% in non-obese men, giving a corresponding increase in testosterone of 180%.
The small sample size makes it an unreliable study. Meanwhile, other studies have failed to corroborate its conclusions. One, investigating the effect of fasting on LH and testosterone, found that both hormones decreased after periods of restricted energy intake. A more recent study again found that energy restriction actually led to a decrease in testosterone levels.
No link between intermittent fasting and testosterone has yet been confirmed, and studies to date have yielded conflicting results.
However, there are promising signs that this eating regimen has positive effects on different hormones, including human growth hormone and insulin.
In the meantime, the other health benefits promised by intermittent fasting may convince you to try it anyway.
Take care of yourself, man.