New study finds that a very low-calorie ketogenic diet increases testosterone levels in obese males by up to 25%.
A peer-reviewed study of 22 obese male patients published in Wiley's Andrology journal on December 2, 2022,(1) found that a low-calorie ketogenic diet resulted in significant and persistent reductions in body weight, BMI, fat mass, blood glucose, insulin, and the HOMA index.
Additionally, there was a significant increase in serum total testosterone levels (+35 ng/dl after 7 days and +74 ng/dl after 28 days), as well as an increase in sex hormone-binding globulin (SHBG) levels. Hypogonadal subjects achieved higher percentages of increase in total testosterone levels (up to +98.12 ng/dl) as well as weight loss and greater reductions in weight, fat mass, and waist circumference than eugonadal subjects.
These findings suggest that a low-calorie keto diet can lead to rapid improvements in total testosterone levels associated with weight loss in male obese non-diabetic subjects.
"A very low-calorie ketogenic diet results in rapid improvements in total testosterone levels associated with weight loss in male obese non-diabetic subjects, particularly in the presence of obesity-related hypogonadism."— Cignarelli, Angelo et al. "Very low-calorie ketogenic diet rapidly augments testosterone levels in non-diabetic obese subjects"
The findings of this study support the findings of a 2020 study in resistance training men in which a ketogenic diet increased total testosterone levels by up to 118 ng/dL after 11 weeks.(2)
"Total testosterone increased significantly from weeks 0 to 11 in the ketogenic diet (118 ng/dl) as compared to the western diet (-36 ng/dl) from pre to post while insulin did not change."— Wilson, Jacob M et al. "Effects of Ketogenic Dieting on Body Composition, Strength, Power, and Hormonal Profiles in Resistance Training Men"
All of the recent research suggests that a ketogenic diet may be a natural method to significantly increase testosterone levels in healthy and obese men, as well as individuals with hypogonadism.