Protein and Testosterone: Does Dietary Protein Intake Affect T Levels?

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Protein is by far the least demonized macronutrient at the moment, and it’s considered to be the holy grail of nutrition. It’s not uncommon to see gym rats and bodybuilding websites recommending to cut down on fat and carb intake, just for the sake of getting in more of the god given protein.

Protein might be the most important nutrient for maintaining lean mass, but for testosterone production? It’s the least important.

That’s right, more protein is not cool for your balls, no matter what the bodybuilding sites (the guys who try to sell you their powders) say.

Here’s why:


How Dietary Protein Impacts Testosterone Production

dietary protein intake and testosterone levelsI have personally never enjoyed high protein diets. Many guys swear by them, but they’re often the guys who sell the powders too.

For these 6 or so years that I’ve been hitting the gym, I have been mostly focusing on fats, carbohydrates, and total caloric intake.

Surely I do eat protein, but I eat a lot less than the bodybuilding sites recommend for a guy of my size. To give you a hint of numbers, I eat probably around half of that.

Yet I have never had any problems building muscle, EVEN when I didn’t have freakishly high testosterone levels.

The reasoning behind me not eating a high protein diet is simple. I want to maintain high testosterone levels naturally, and high protein diets are detrimental for T production. The more you eat protein, the more you have to cut out from your carbohydrates and fats, and the more you cut from those two, the lower your testosterone production will be.

And that’s because fats and carbs are superior to protein when it comes to natural testosterone optimization.

This is obvious when you take a look at the research:

a) In this study, the researchers divided their subjects into 2 groups. The other group ate a high-carb low-protein diet, whereas the other group ate a high-protein low-carb diet. Fat intake and calories were identical. Ten days into the study, the results showed that the high protein group had significantly lower free testosterone levels (-36%), higher SHBG levels, and higher cortisol levels.

b) In this study which had 1552 men as test subjects (aged 40-70), Longcope et al. found out that when men eat low amounts of protein, their levels of sex hormone binding globulin (SHBG) increase. This occurrence is believed to lead to reductions in free testosterone levels (SHBG is a protein which binds to free testosterone molecules in blood, making them ‘unavailable’ for direct use of the body). So at least in older men, low-protein intake might be a bad idea. What is low-protein according to these researchers though? Much lower than the amount recommended below in this article 😉 .

c) In this study, the researchers found out that diets high in protein, lower testosterone levels in men who practice strength training.

d) In this Finnish study, Hulmi et al. found out that consuming a drink with 25 grams protein (whey and casein) right before a strength training workout, significantly lowered testosterone and growth hormone levels in human subjects.

So as you can see, protein truly is the least important macronutrient when it comes to boosting testosterone. I wouldn’t say that it’s necessarily a bad nutrient or anything like that, but eating a high protein diet leaves room for less carbs and fat, which are superior when optimizing natural T production.

The source of protein also seems to be important. For testosterone optimization, animal sources are superior to plant sources, especially if your goal is to build muscle.

If you’re actively lifting weights, I would recommend that about 25-30% of your daily calories come from animal proteins. This is easily enough for muscle building purposes (if, for some weird reason, you would still want to consume more protein than that, it would be best to consume more protein in your workout days, and less in your rest days, in a way that your total weekly protein intake would still be about 25-30% of your calories).

What about protein powders like whey and casein?

Answer: I honestly wouldn’t even recommend protein powders. The way I see it, it’s just that the companies which sell them are making some big time bank of off people who believe that they need to have that protein drink after a lifting session, if they don’t, the whole workout was useless.

Just get your protein from fatty cuts of meat, and if you absolutely can’t meet your daily goal from animal sources, then maybe take a sip of casein before bed, or whey after a workout.

But whatever you do, please don’t be as enthusiastic about protein as the guys below. 😀




Protein is the least important macronutrient for testosterone optimization, but is quite important for lean muscle mass…

With that being said, I believe that the recommended intake of protein pushed by the fitness industry is way too high. You could easily build muscle with lower intake, without compromising your testosterone levels in the process.

Aim to get about 25-30% of your daily calories from animal protein, if your goal is to build muscle while maintaining high testosterone levels. If you don’t workout at all, then 20% should be enough.

Ali Kuoppala

Ali Kuoppala is the founder of Anabolic Men, and an Independent Researcher that has been credited with organizing the findings that have helped thousands of men reach hormonal balance. alikuoppala @anabolicmen
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  1. James Evans II on 05/01/2015 at 04:07

    Great article. How many grams would you
    recommend for a 6’2 200lb male at 12% body fat looking to trim down to 8%? I have been getting in 1g per pound of lean body mass, but it’s difficult consistently getting that amount.

  2. bahadur on 05/01/2015 at 07:14

    hey Ali, I am skinny but not lean. I have kinda high bf%. I am thinkin about eating 5000 calories a day to bulk up?? I am also doing heavy compound weight lifting and sprints… Is eating that amount will lead me to huge muscle gain or I will end up getting fat??

  3. Pedro Mendes de Araújo on 18/01/2015 at 22:47

    Ali, do you still recommend iodine painting? Do you still do it?

  4. ΑΝΔΡΩΜΕΑΣ on 28/02/2015 at 21:19

    you are right..the abstract say “Thus, diets low in protein in elderly men may lead to elevated SHBG levels and decreased testosterone bioactivity.”

  5. Orion Antares on 14/10/2015 at 17:52

    You linked to a study about replacing meat with soy for protein to show that animal sources are better than plant protein sources for testosterone. Does this actually show that animal proteins are better than plant proteins or just that they are better than soy proteins?

    • Martin351 on 05/04/2016 at 03:54

      animal proteins are better than plant proteins, because most plant proteins contain xeno-estrogens which completely counteract the production of testosterone. They do this by blocking the metabolic pathways in which testosterone is created but instead used to create more estrogen.

      • Orion Antares on 05/04/2016 at 22:31

        Aren’t noticable levels of phytoestrogens an issue limited to soy?

  6. Ian Rowley on 02/12/2015 at 22:25

    Hello Ali. Really good website. But I have a question about your recommendation for protein. You recommend a ‘moderate’ protein of 20-30% of calories. For a average man who needs 2500 – 3000 kcal/day, that’s 125g to 225g per day. That’s a lot. I train and weigh 180 – the usual guideline is 1g per Ib bwt, so I need 180g. Therefore your ideas are roughly in line with the conventional guidelines. But you say the ‘recommended intake’ is way too high.
    Can you explain this?

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