CHICAGO — It’s been shown that losing excess weight can help men diagnosed with low testosterone raise their levels of the essential male sex hormone. However, a new set of research performed in Chicago finds a low-fat diet probably isn’t the best choice for many men looking to lose weight and raise their testosterone. Researchers say such a diet is associated with a small, but significant decrease in testosterone levels.
“We found that men who adhered to a fat restrictive diet had lower serum testosterone than men on a nonrestrictive diet,” comments Jake Fantus, MD, of the Section of Urology, Department of Surgery, University of Chicago Medicine, in a release. “However, the clinical significance of small differences in serum T across diets is unclear.”
Using data collected from a nationwide health survey, the research team analyzed over 3,100 men, including information on each man’s dietary habits and serum testosterone level. In all, 14.6% of included men fit the criteria for a low-fat diet (per American Heart Association guidelines), while 24.4% followed a Mediterranean diet (lots of fruits, vegetables, and grains & low amounts of animal protein and dairy). Additionally, only a small number of analyzed men followed a low-carbohydrate diet, so they weren’t included in the subsequent analysis.
Among all analyzed males, the average serum testosterone level was 435.5 ng/dL (nanograms per deciliter). However, men following a low-fat diet had an average T-level of 411 ng/dL, and men following a Mediterranean diet came in at 413 ng/dL.
After these initial observations, the research team decided to account for additional outside factors that may influence one’s testosterone levels, such as age, BMI, exercise habits, and medical history. After refining their results, a low-fat diet was still shown to be significantly associated with reduced serum testosterone. However, a Mediterranean diet no longer showed a connection.
In total, 26.8% of the analyzed men had a testosterone level less than 300 ng/dL, which is typically considered the cut off point when diagnosing a case of male testosterone deficiency. Interestingly, despite the fluctuations in average testosterone levels across dietary choices, the proportion of men dealing with low levels of the hormone was similar across all diets.
Low testosterone certainly isn’t a rare condition in the United States. In fact, it’s estimated that an additional 500,000 American males are diagnosed with a deficiency each year. Common symptoms attributed to low levels of the hormone include decreased energy and sex drive and weaker bone density.
Upon diagnosis, most men are prescribed a medication to help with the issue, but many doctors also recommend exercise and weight loss. However, just how influential one’s diet is on testosterone levels has always been unclear. Testosterone, a steroid, is derived from cholesterol, so it’s long been theorized that fat consumption habits play some type of role in testosterone levels. Now, this new set of research is indicating that a low-fat diet is actually worse for testosterone than a generally un-restricted diet.
All that being said, the study’s authors stress that the best diet for a man looking to boost his testosterone depends on the individual. For overweight men, a low-fat diet is probably still very beneficial for raising one’s levels, even after accounting for the reduction in serum testosterone that such a diet may bring about. Conversely, it may be a better idea for non-overweight men to avoid a low-fat diet.
The study is published in The Journal of Urology