When you have very low body fat and eat fewer calories, your body lowers testosterone levels to save energy for staying alive instead of making babies.

When you don't eat enough food and your body fat gets very low, your body slows down the hormones that make testosterone, focusing on staying alive instead of having kids.

When men have very low testosterone for a long time, it can mess up their metabolism and make their body and mind not work as well as they should.

Low-carbohydrate, high-fat diets are associated with higher basal testosterone levels compared to high-carbohydrate diets in healthy adults.

When overweight men eat a very low calorie diet for 12 weeks, their testosterone levels go up a lot, which can help improve their health.

The amount of fat consumed in the diet is associated with changes in testosterone levels in the blood, with higher intake between 50 and 150 grams per day linked to higher levels.