Testosterone is involved with a lot of functions in the body. It aids bone growth and strength, sex organ development, cognition and mood. The most popular function of testosterone is its impact on strength and muscle growth. Getting bigger and stronger muscles are naturally common goals of athletes. Trying to optimize testosterone levels is a big topic of interest as a result. Pairing this with protein’s impact on muscle and strength, the two complement each other well. Recent studies are starting to question though if focusing too much on protein could actually result in having protein impact testosterone negatively.
Current recommendations for optimal protein impact
Recommendations for protein are typically based on one’s body weight. Current sports nutrition guidelines for those looking to build muscle and maximize recovery is around 1.8-2.2g/kg. For a 170 pound person that’s ~155 grams of protein per day. Getting 2g/kg of protein is already challenging for most people. Others though go with the theory of if some is good, more has to be better! Studies looking into even higher intakes are starting to increase though to test the limits. Conducting more studies though makes the definition of “high protein” tough to quantify though as each study may have a different number for it.
Quantifying “high protein”
Reviewing many of the studies in this paper it appeared that the cut-off of “high protein” was around 3.4g/kg. Compared to 2g/kg mentioned earlier that is a huge jump! It’s unlikely that someone would achieve this level without putting in a lot of intentional effort. Most of the studies looking at that level of intake though did show it was effective at improving body composition. Score one for high protein! The same researchers also looked into how it impacted kidney and liver function as that tends to get brought up as a common concern. Findings pointed to no negative impacts on kidneys and liver either. Sore two for high protein! Not studied though was testosterone which a recent paper dove into.
Too much protein impact on testosterone
Consuming at or above that 3.4g/kg does appear to decrease testosterone levels. Cutting right to the chase on that one! We’re still early in the research on this topic so nothing definitive can be made but there are trends worth noting. Below 3.4g/kg these effects appear to be minimal or non-existent. Looking at various studies playing around with carb and fat intakes they don’t appear to have the same impact on testosterone. Minus one for high protein this time. Decreasing testosterone appears to be the body’s way to increase its ability to digest and process the added protein through different pathways. Physiologically then it would make sense for this to be occurring with very high protein intake.
So how much protein should be consumed?
Most people struggle to hit just 2.0g/kg and that is what I would recommend starting at. Consuming 2.0g/kg has been shown many times over to be sufficient to help aid muscle building and repair. This is also low enough to avoid any potential negative impacts on testosterone so it’a a good benchmark to strive for. Certain situations such as injury recovery may need more but the vast majority of athletes and the general public would do great at that 2.0g/kg mark. As an example, at this amount a 170lb. person would need around 155g per day of protein. Make sure your meals and snacks all have a good protein source with them and enjoy the gains!
Study referenced: click here