Hypogonadism and male obesity: Focus on unresolved questions.
Plain-language summary
This review looked at the link between obesity and low testosterone in men, focusing on how weight affects hormone levels and what treatments might help. It examined studies on men with obesity, comparing how weight loss through lifestyle changes or bariatric surgery affects testosterone levels, and whether testosterone treatment improves symptoms or body composition. The review found that obesity lowers testosterone mainly by reducing sex hormone-binding globulin (SHBG, a protein that binds testosterone and sets how much is free and usable) and, in severe cases, by suppressing the hypothalamic-pituitary-testicular axis (HPT, the hormone system that drives testosterone production). While bariatric surgery effectively boosts testosterone, lifestyle changes have a smaller effect, and testosterone treatment does not reduce weight but may modestly improve body composition and symptoms in some men.
Key findings
- Obesity lowers testosterone by reducing SHBG and, in severe cases, suppressing the HPT axis.
- Bariatric surgery effectively reactivates the HPT axis in markedly obese men.
- Lifestyle changes lead to modest increases in testosterone.
- Testosterone treatment does not reduce weight but may modestly improve body composition and symptoms.
How to analyze the study yourself
- Study type
- Narrative reviews summarize existing evidence but do not systematically pool data or control for bias, so they provide a broad overview rather than definitive conclusions.
- Population
- Men with obesity, including those with severe obesity who underwent bariatric surgery.
- Funding
- Not reported
- Takeaway
- This review found that markedly obese men who underwent bariatric surgery, saw substantial weight loss which was very effective in reactivating the HPT axis. In contrast, lifestyle measures were less effective in reducing weight were only associated with modest increases in testosterone. If you are overweight and have low testosterone, it's worth losing weight. Bariatric surgery can be discussed with your doctor if necessary.