Fatty foods may be good for men, study claims

A low-fat diet lowers testosterone levels in males, which increases the risk of cardiovascular disease, diabetes, and Alzheimer's disease, UK researchers noted.

Their new study was published in the Journal of Steroid Biochemistry and Molecular Biology.

The researchers conducted a systematic review of scientific papers with a total of 206 participants. The men first ate a high-fat (40%) diet and then switched to a 20% fat diet. The testosterone level decreased by an average of 10-15%. Vegetarian diets were especially bad in this regard, causing testosterone to drop by up to 26%.

A high intake of monounsaturated fats, found in olive oil, avocados, and nuts, can increase testosterone production. However, omega-6 polyunsaturated fats, which are predominantly found in vegetable oils, can damage testosterone-producing cells when oxidized.

Dietary recommendations usually focus on limiting fat intake, and current UK and US regulations limit fat intake to less than 35% of total calories. However, more and more studies are now emerging showing the benefits of high-fat, low-carb diets.