Does the Keto Diet Lower Testosterone?

Does the Keto Diet Lower Testosterone?

Fat is essential for proper hormone production.

That statement is a fact. Fat helps regulate the production of hormones in the body, including testosterone. The necessary level of fat can be debated, but the American Heart Association recommends 20-35% of daily calories come from fat.

Thus, for a 2,000 calorie a day diet, that is 400-700 calories or 44-78 grams of fat per day. This is what the body will require to produce optimal levels of hormones and also to function properly.

Related - 30 Ways To Boost Your Testosterone Naturally

Since fat is linked to adequate testosterone, one would think that a ketogenic diet or another higher fat diet would lead to even higher levels of testosterone and advocates for these diets have even promoted that. Or, at the very least, it wouldn't have any negative effect on hormone levels, right?


Your keto diet might be turning you into a woman! Well, maybe not that extreme, but it appears that it might be possible to have too much of a good thing. Can low carb, or ketogenic diets lower your testosterone?

Based on available data, it absolutely can!

Firstly, glucose is responsible and plays a huge role in GnRH levels which lead to hormonal actions in the body. GnHR is a releasing hormone responsible for the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary.

These are all critical to the production of testosterone and other hormones. This can be one reason why these studies I am about to mention turned out the way they did. [1]

When carbs were reduced to 30% of one's diet, even more, carbs than most ketogenic diets recommend, testosterone and the ratio of testosterone to cortisol was reduced significantly in subjects. This wasn't just in normal people - this was also replicated in Olympic athletes. [2]

Cortisol levels skyrocketed as the athletes depleted glycogen and increased the cortisol to testosterone ratio in these highly-trained athletes. The effect was blunted and reversed with the inclusion of a carb-containing shake.

This is even more evidence than when I recommend a shake with MTS Nutrition Machine Whey and Machine Carb 10 IMMEDIATELY post workout, regardless of diet, you are doing great things for more than fat loss, but for recovery and hormone response to training. [3]

I recommend a balanced diet, as found in the Drop Factor Book, so don't think we are advocating super-high carbohydrate diets, but the evidence to include carbs in your diet is hard to ignore. In one study, high carb diets increased testosterone by 36% over low carb diets. [4] The carb group also had lower levels of the stress hormone, cortisol.

But I was told that carbs make you fat?

Contrary to what the people trying to sell you stuff or sell books or simply have befriended Oprah, diet is pretty simple and regardless of what your diet beliefs are, there is one thing we all agree upon:

Exercise is Awesome

Diet is very important, but to ward off a lot of lifestyle diseases like type-2 diabetes and obesity, a consistent exercise plan should be a part of your life. We have a TON of options available at TigerFitness, but the training found in the Drop Factor Book is a great option!

Back to Diet

The main variable to losing fat and gaining muscle is a caloric balance. Take in more calories than you burn and you will gain weight. Take in less than you burn and you will lose weight. Some simple dietary rules of thumb:
  1. Set protein to 1-1.5 grams per pound of body weight daily.
  2. Set Fat to 0.3-0.5 grams per pound of body weight daily.
  3. Fill in the rest of your caloric needs with carbs.
  4. Find your TDEE, or Total Daily Energy Expenditure HERE (How many calories you need per day).
  5. Find the macronutrient breakdown you want and calculate macros based on your TDEE here.
  6. As stick point are hit if losing fat, drop carbs by ~40-60 grams per day (based on weekly progress to lose 1-2 lbs a week) or increase activity (cardio).
  7. As stick points are hit if trying to gain mass, increase carbs by ~40-60 grams per day (based on weekly progress to gain .5-1lb a week) or just check out Mass Diet.

The Take Home

I wouldn't worry about keto lowering your testosterone one bit. If you enjoy the diet, DO IT!

Sticking to it will be much better than a free-for-all of fat gain. But the message here is that there is no perfect diet. Do what works for you and please check out all of the resources in this article to help you find the perfect diet.

Please comment down below what works best for YOU so that your experiences can help out fellow readers!
1) Roland, AV et al. Regulation of gonadotropin-releasing hormone neurons by glucose. Trends Endocrinol Metab. 2011; 22(11): 443-9
2) Lane, AR et al. Influence of dietary carbohydrate intake on the free testosterone: cortisol ratio responses to short-term intensive exercise training. Eur J Appl Physiol. 2010; 108(6): 1125-31
3) Gleeson, M et al. Modification of immune responses to exercise by carbohydrate, glutamine, and anti-oxidant supplements. Immunology and Cell Biology (2000) 78, 554561
4) Anderson, KE et al. Diet-hormone interactions: protein/carbohydrate ratio alters reciprocally the plasma levels of testosterone and cortisol and their respective binding globulins in man. Life Sci. 1987; 40(18): 1761-8
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Craig Carpenter - April 1, 2019

The only thing I can garner from this completely misleading article is that you want people to buy your products, go to your gym, or die horrible deaths from diabetes, obesity, and/or heart attack. A keto diet has been in use for as long as humans have been on earth and we have propagated the species just fine. A real foods diet of high fats and low carbs is the natural diet of homosapiens sapiens. It has only been in the last few thousand years and especially in the last 300 or so that humans have shifted to a diet consisting of 40 to 60 percent carbs. Do a bit of actual research into lipidology and the natural function of the digestive system. Then consider the lies that you’ve been told by the AMA, ADA, and AHA.

Soltura Cuba Travel - July 15, 2018

Fatty acids break down into glucose via gluconeogenesis. You seem to know what you are talking about, so one can only conclude that you are being intentionally misleading for personal gain.

Lowcarb - March 13, 2018

Aaron, Funny I am 61 have been doing Keto for 26 years. I had a Test check last year and it was 1097. High is 900. Lifetime Natural competitor tested over 30 times, NANBF Promoter. I find this article conflicting.

Go to Wikipedia and look up “Cholesterol”. It says it is the precursor to all Hormones Testosterone etc. Making up your calories of primarily plant food and lessor of Saturated Fat ( The type of fat is most important BTW) for a Natty would be less than optimal in my experience. The cookie cutter ratio here would put me at 45-80 fats. That is lowfat dieting of old and I was soft at contest and lost size and strength every time doing that. Once I went to more like 110-130 grams it was like doing gear in comparison. Using this I was Lean and hit PR’s the week of shows in the gym a sign of no loss of muscle and possible gains on a Prep.

A lot of it is age related. A late teen to mid 20’s guy if they cut our junk food and beer just about any diet will appear to work. This is how much of this is skewed. What works for a guy that is 35 should shed light on what is really the best and optimal for Natty’s.

John Best - October 11, 2017

I tried the drop factor diet last spring and loved it.

Aaron Miller - October 4, 2017

Hey Marc, if Keto diet kills testosterone and people say that low fat diet kills testosterone as well. Why is that? Would not keto raise testosterone if low fat diet kills test?

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