Low-Fat Diets and Testosterone in Men
Systematic review and meta-analysis of intervention studies.
If you’ve ever wondered how your diet might be influencing your testosterone levels, especially if you’re considering or following a low-fat diet, this study might be up your alley.
Testosterone plays a crucial role in men's health, affecting everything from muscle mass and energy to chronic disease risk and overall mortality. Understanding how dietary fat impacts testosterone can help men make informed nutrition choices.
Key Points
Aim:
This study systematically reviewed and meta-analysed intervention trials to determine the effect of low-fat diets compared to high-fat diets on testosterone and related sex hormones in men.
Methods:
The authors searched nine databases up to October 2020 and included six intervention studies with a total of 206 male participants.
These studies compared the effects of low-fat versus high-fat diets on sex hormone levels, minimising confounding factors.
Meta-analyses with random effects models were conducted to assess the standardised mean differences in hormone levels.
Quality was assessed using Cochrane’s risk of bias tool.
Results
Testosterone Levels: Low-fat diets significantly decreased total testosterone levels compared to high-fat diets, with a standardised mean difference (SMD) of -0.38 (95% CI: -0.75 to -0.01, p=0.04).
Free Testosterone: Also significantly reduced on low-fat diets (SMD -0.37, 95% CI: -0.63 to -0.11, p=0.005).
Urinary Testosterone: Decreased with low-fat diets (SMD -0.38, 95% CI: -0.66 to -0.09, p=0.009).
Dihydrotestosterone (DHT): Showed a significant reduction (SMD -0.3, 95% CI: -0.56 to -0.03, p=0.03).
No Significant Change: Luteinising hormone (LH) and sex hormone-binding globulin (SHBG) did not significantly differ between diet types.
Ethnic Subgroup: Men of European and North American descent experienced a stronger decrease in total testosterone on low-fat diets (SMD -0.52, 95% CI: -0.75 to -0.3, p<0.001).
Related
Practical Takeaways
Dietary Fat Intake Matters: Reducing fat intake substantially may lower testosterone levels, which could impact muscle building, recovery, energy, and overall male health.
Balance is Key: While low-fat diets are often recommended for cardiovascular health, men concerned about maintaining optimal testosterone might consider ensuring adequate healthy fat intake.
Ethnic Variability: Men of European ancestry might be more sensitive to fat intake changes regarding testosterone, so personalised nutrition could be beneficial.
Hormone Monitoring: If adopting a low-fat diet, monitoring testosterone levels might be prudent, especially for those experiencing symptoms of low testosterone.
Summary
This meta-analysis provides evidence that low-fat diets can lower testosterone and related androgen levels in men compared to high-fat diets. However, the authors caution that more randomised controlled trials are needed to confirm these findings definitively. The observed hormonal changes did not extend to luteinising hormone or SHBG, suggesting the effect is specific to testosterone production or metabolism. These findings highlight the importance of dietary fat in hormonal health and recommend that men should consider fat intake carefully in diet planning, especially if maintaining testosterone levels is a priority.
In the end, if you’re aiming to optimise your testosterone through diet, drastically cutting fat might not be the best strategy. Instead, maintaining a moderate to higher fat intake could support healthier testosterone levels, which is vital for strength, vitality, and long-term health.
Reference
Whittaker, J., & Wu, K. (2021). Low-fat diets and testosterone in men: Systematic review and meta-analysis of intervention studies. The Journal of Steroid Biochemistry and Molecular Biology, 210, 105878. https://doi.org/10.1016/j.jsbmb.2021.105878
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