Although there’s new evidence that low-fat diets might decrease serum testosterone in men, don’t go rushing out to grab some fries quiet yet. The study has yet to prove whether the reduction is clinically meaningful and the potential benefits of a low-fat diet may far outweigh a slight reduction in serum testosterone for men who are obese. In addition, sometimes weight reduction leads to an increase in testosterone levels.
Three diets
The researchers wanted to understand if and why some diets raise or lower testosterone levels. They decided to study the effects of three diets on testosterone. The diets included:
- a nonrestrictive diet
- the Mediterranean diet (lots of fruits, vegetables and whole grains but minimal diary and animal products)
- a low-fat diet
For their research, the team looked at data from men (ages 18080) the National Health and Nutrition Examination Survey. The men had all submitted a two-day dietary history and serum testosterone measurements.
Of the 3,126 men, 764 men ate the Mediterranean diet, 457 men ate a low-fat diet and the rest followed a nonrestrictive diet.
The results
The researchers adjusted for factors that affect testosterone, such as BMI, age and activity, and found that the Mediterranean diet didn’t significantly reduce testosterone. But they did find that the low-fat diet reduced testosterone in a manner that was “small but significant” compared to a nonrestrictive diet. More specifically, the study showed:
- the mean serum testosterone for all the men was approximately 435.5 ng/dl
- the average serum testosterone for men on the Mediterranean diet was 413 ng/dl
- the average serum testosterone for men on the low-fat diet was 411 ng/dl
So, is this finding a big deal? Yes and no. for men who have a testosterone deficiency and are already maintaining a healthy weight, they might want to consider a different diet other than low fat. Still, more research needs to be done.
