Low-Fat Diets—Do They Contribute to Low Testosterone Levels?

Dietary information, which is often based on conjecture and marketing spin, can be both confusing and contradictory for those looking to improve their overall health.

Many of us remember the days when almost all fat was labeled bad for you.

However, modern nutritional fads like the Keto and Paleo diets recommend consuming much more fat and large portions of protein while restricting carbs.

Looking to research rather than hype, there may be a very good reason why men should be keeping up their intake of healthy fats:

Men who are already at a healthy weight yet routinely consume fewer calories and fats may be at an increased risk for lower testosterone levels.

Young man in a white t-shirt holds fresh vegetables. Medical research shows that a low-fat diet can contribute to low testosterone under some circumstances.

Researching the Impact of Low-Fat Diets on Testosterone Levels

In a recent study published in the Journal of Urology (February 2020), medical researchers used multivariable modeling to examine the relationship between serum testosterone levels and low-fat, Mediterranean, and low-carbohydrate diets.

The subjects studied were 3,128 men between the ages of 18 and 80 who participated in the National Health and Nutrition Examination Survey (NHANES), a 2-day dietary history.

Based on Dietary Intervention Randomized Controlled Trial group criteria, 457 men (14.6%) were identified as following a low-fat diet, and 764 men (24.4%) were identified as following a Mediterranean diet.

Mean testosterone was lower among men with a low fat diet (410.8 ng/dL) and a Mediterranean diet (412.9 ng/dL) compared to the overall mean serum testosterone levels (443.5 ng/dL).

Multivariable analysis was utilized to control for the following variables:

  • Age
  • Body mass index
  • Activity level
  • Diabetes
  • Comorbidities
  • Prostate cancer

Lead researcher Jake Fantus, MD, from the University of Chicago, concluded:

“We found that men who adhered to a fat-restricted diet had lower serum testosterone than men on a nonrestrictive diet.”

Those findings would seem to clearly indicate that low-fat diets are bad for your hormonal health and should be avoided, but the researchers also state that these results aren’t all-encompassing. They aren’t yet clear how significant these small testosterone differences across diets are, and more research will be needed to determine their overall medical implications.

To quote the study itself:

“As differences in serum testosterone between the diets were modest, the avoidance of fat restrictive diets should be weighed against the potential benefits on an individual basis.”

Read the study abstract here.

What The Results Might Mean for You

If someone is already physically active and in otherwise good condition, staying on a fat-restricted diet to keep any unwanted pounds off could have detrimental effects.

If this sounds like you, it may be advisable to lean toward a more moderate-fat diet to maintain or improve your hormonal health.

On the other hand, we know that Low T and weight gain are intertwined, each condition exacerbating the other. Chronic low testosterone levels contribute to an increased production of fat tissue, and more fat tissue increases estrogen production, which effectively drives testosterone levels down.

Therefore, breaking this spiral may take priority over the potential downside of the low-fat diet.

To put that another way, it’s important to remember that each individual is different, and a conversation with your healthcare provider is recommended before making any major decisions. Depending on your current health and lifestyle, the testosterone-raising benefits of weight loss might outweigh the slight decrease in overall testosterone production associated with the low-fat diet.

The Role of Low Testosterone in Weight Management

If you’re a man who is somewhat overweight and potentially suffers from Low T, controlling your weight or achieving significant weight loss is going to be more difficult.

A chapter of our comprehensive guide is dedicated to providing facts and answers to the most common questions regarding the role of low testosterone in weight control, lean muscle production, and the prevention of premature frailty.

Read the Guide


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(Augie) Juan Augustine Galindo Jr. MPAS, PA-C

(Augie) Juan Augustine Galindo Jr. MPAS, PA-C started his career in healthcare as a fireman/paramedic in West Texas where he served on the Midland Fire Department from 1998-2004.   He became interested in testosterone treatment after seeing how hormone replacement doctors helped those suffering from low testosterone.   After graduating from the Texas Tech Health Sciences Center Physician Assistant Program, he moved to DFW where he currently lives with his wife and three children.

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