Is Low Testosterone Making You Fat?

We all have some amount of testosterone in our bodies, but it's more of a game-changer for men. The hormone controls many of the traits associated with masculinity and virility, such as muscle development, facial hair growth and a deep voice. In fact, men have up to 20 times more testosterone than women (which is why females generally don't need to worry about "bulking up" as a result of strength training).

What many don't realize is that testosterone also plays a key role in losing and managing weight. If you're a man who is trying to build muscle or slim down, the amount (or lack) of testosterone in your system can significantly impact your results.

In research studies, among men who qualified as obese, 75 percent were found to have hypogonadism, a condition where the body produces low testosterone.

Although the levels naturally decrease with age, males of all ages can experience T-triggered weight gain. In addition to age, testosterone can also be lowered by poor diet, excessive exercise and serious illness. Weight gain isn't the only symptom—some other red flags include lagging libido, lower fertility, reduced muscle strength, weaker bones and less energy.

How Does Testosterone Affect Weight Gain?

According to Tyler Spraul, director of user experience at, testosterone can help speed up weight loss in two ways: by promoting muscle growth and by helping to reduce body fat.

On the muscle growth side, testosterone works to increase protein synthesis in the body and also raises the levels of growth hormones, so your workouts are more likely to build muscle. "While this may seem counterproductive for weight loss, building muscle is beneficial because that muscle will burn more calories throughout the day than the same amount of fatty tissue would," Spraul explains.

When it comes to reducing body fat, testosterone has an important influence on insulin, glucose and fat metabolism. As testosterone decreases, the body becomes less efficient in fat metabolism and more likely to store excess energy as fat.

"Another benefit of increased testosterone is that it combats the negative effects of cortisol, which is sometimes responsible for stalled weight loss," says Alexander McBrairty, NASM-certified personal trainer with A-Team Fitness.

Before you blame testosterone for that extra 10 (or 20 or 50) stubborn pounds that have been hanging on for dear life, know that it's not necessarily a one-way relationship. Although low T levels can indeed cause weight gain, the inverse can also be true: Extra weight can trigger a hormonal decline.

Can You Boost Sagging Testosterone Levels?

If your tests reveal low testosterone, you don't have to resign yourself to carrying around extra pounds. In one study, 255 men who received testosterone treatment reported a significant decrease in body weight and waist circumference over a five-year period. But hormone replacement therapy isn't the only solution. According to McBrairty, elevated T-levels could be just a weight (or two) away.

"Testosterone levels increase as a result of resistance training in both men and women," says McBrairty. "More specifically, performing large, compound movements, such as deadlifts and squats, have been shown to have the greatest effect on post-workout testosterone levels." For a greater T-boost, McBrairty recommends including moderate to heavy volume sets separated by short rest intervals.

In addition to strength training, nutrition is a key element of maintaining proper hormone levels. Mike Matthews from Muscle for Life stresses the importance of eating a high-protein, high-carb and moderate-fat diet, and ensuring that you're not in a caloric deficit.

If you suspect that your testosterone levels have dipped, you can make an appointment with your doctor to get a blood test. If the results are abnormal, the doctor will most likely order a second test for verification.