How Belly Fat Affects Testosterone Levels

Visceral fat leads to lower T levels through aromatization, inflammation, oxidative stress and insulin resistance.

Researchers have known for some time that belly fat is more pernicious than once thought. Extensive research has shown that visceral fat, the fat that’s stored deep inside the abdominal cavity, is biologically active and is harmful to both men’s and women’s health. 

One of these negative effects is a drop in testosterone levels in men. Research is still ongoing to fully understand the link between belly fat and T levels. 

But based on what we know so far, there are three ways having a large belly lowers your T levels, which in turn causes a host of other problems including lower libido, erectile dysfunction, loss of muscle mass and poor mental health. 

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Quick Primer: What Exactly is Belly Fat?

We have two main kinds of fat in the body: subcutaneous fat and visceral fat. 

90% of body fat is the subcutaneous kind. It is found right under the skin; it’s the pinchable kind of fat. Subcutaneous fat plays many important roles including insulation, as a cushion for internal organs and as an energy source. 

Visceral fat is found deeper inside, under the abdominal wall. It surrounds internal organs like the liver, stomach, intestines, and heart.  

Belly fat is the common name for visceral fat. A sign that you have too much visceral fat is an increase in belly size and waist circumference. This happens as an accumulation of visceral fat pushes out the abdominal wall.  

3 Ways Visceral Fat Lowers Testosterone 

1. Aromatization 

Visceral fat doesn’t just sit there passively. It is biologically active, producing hormones and other chemicals that affect your health. 

Aromatase, an enzyme, is one of the substances produced by belly fat. Aromatase converts androgens like testosterone into estrogens. 

Estrogen has a negative feedback effect on testosterone. That means that as estrogen levels rise, the body produces less testosterone. It is one of the reasons why many obese men have lower levels of testosterone, and why weight loss results in a rise in T levels as the amount of belly fat goes down.  

Aromatization of testosterone can also contribute to enlarged breast tissue in overweight or obese men, a condition called gynecomastia.

2. Chronic Inflammation & Oxidative Stress 

Fat cells also release inflammatory substances like cytokines and adipokines. This leads to chronic inflammation in the body. Inflammation is linked to many serious health problems including heart disease, type 2 diabetes, and autoimmune diseases. 

Leydig cells, which are responsible for testosterone production, are sensitive to inflammation. Chronic inflammation can cause dysfunction of Leydig cells, leading to lower T levels.  

Belly fat also increases oxidative stress, which happens when there are too many free radicals in the body. Free radicals, also called reactive oxygen species (ROS), cause cell damage. 

The combined effect of inflammation and oxidative stress causes serious damage to Leydig cells. What’s worse is that the two processes exacerbate each other. Inflammation causes more oxidative stress and vice versa. 

3. Insulin Resistance 

Belly fat is strongly linked to increased insulin resistance. The most common result is the development of type 2 diabetes as the body struggles to control blood sugar. 

It can also tank your testosterone levels. This happens through several pathways. 

High blood sugar, resulting from insulin resistance, causes increased inflammation. And as we’ve discussed, this can lead to dysfunction of T-producing Leydig cells. 

Insulin resistance also enhances aromatase activity, leading to conversion of more testosterone into estrogen. 

Elevated levels of insulin, again resulting from insulin resistance, also have a direct effect on Leydig cells. Insulin inhibits steroidogenesis, the process that produces testosterone in Leydig cells.  

There are likely additional ways high insulin and blood sugar levels impair the production of testosterone. 

It’s Reversible

The good news is that most of the negative effects of belly fat on T levels are reversible. Once you start losing weight and shedding visceral fat, testosterone bounces back to normal levels. 

Exercise, a healthy diet and other lifestyle changes (e.g. good sleep, less alcohol consumption, no smoking etc.) are the best ways to lose belly fat and get your T levels back up.