The T Protocol is a complete review of what is known to optimise Testosterone in Men.
Originally intended as a single resource, it has grown into a series of posts on key areas that Men need to address in order to realise the natural Testosterone levels that are their birth right.
Intuitively, Men seem to know that their diet must affect their Testosterone levels. But what is really known about how diet affects Testosterone, and what is simply myth?
Here we will address how the Macronutrients (Carbs, Fat and Protein) in your diet affect your Testosterone levels. Then we will present some simple eating regimens to optimise your T!
T and Carbs
Carbs. Once the darling of the health and fitness industry, now the sworn enemy of PT’s everywhere trying to get their clients beach ready. Since saturated fat has had a reprieve amongst knowledgeable health and fitness enthusiasts, Carbohydrates, and specifically simple carbohydrates, are taking a bashing.
Add to this the observation, that overweight, middle aged Men, who have metabolic diseases like type 2 diabetes, have low T. Then mix in the understanding that they usually get into this state by eating a diet high in processed and refined carbohydrates, and you have a perfect open and shut case to avoid carbs.
Alas, if only life was so simple.
Numerous studies support the idea that glucose in particular, mediates the HPG axis (Roland 2011). Remember, the Hypothalamic Pituitary Gonadal axis is what ultimately produces T. It would appear that the brain is able to sample blood glucose levels and reduce the activity of the HPG axis if blood glucose is too low. Whilst Fat and Protein can increase blood glucose levels, neither are as effective as carbs are at doing so.
This makes complete sense, fertility is closely coupled to nutrition. The reproductive system must sense changes in bodily energy status and prevent reproduction during times of food scarcity, then maximise reproduction during times of plenty.
Insulin release is stimulated most potently by carbohydrate ingestion, and Insulin also stimulates the HPG axis to produce more T as well as reducing Aromatase activity (Pasquali 1995). Aromatase is the enzyme that converts your Testosterone into Oestrogen. At first glance some of the studies appear to confound this, higher insulin levels in epidemiological studies are associated with lower T (Pitteloud 2005). But what holds true for a lean healthy Male, is the reverse for an Obese Male suffering from metabolic derangement.
Chronic high insulin levels decrease T in Obese Men because the HPG axis becomes resistant to Insulin. It stops responding. In fact T has been shown to proportionally diminish with both increasing BMI and indices of insulin resistance (Osasuna 2009).
The only way to remedy this for these Obese Men is to reduce their Insulin levels, for long enough, that they recover their sensitivity to it. This is one of the many reasons why a low carb diet is effective in getting results in this particular population. Interestingly, the relationship between T and Insulin works the other way round, it is bidirectional (Pitteloud 2005). Adding T exogenously to Obese Men improves their insulin sensitivity (Traish 2009).
If you are already lean, it is clear that Carbs and Insulin stimulate T release.
If you are training hard, or have a period of ‘over-reaching’ Carbs are also essential to your recovery.
Lane (2010) found that after three consecutive days of intense training, a group of Men ingesting 60% of their calories as carbs, had no decrease in their T levels, compared to a 43% decrease in T in a group who were only taking in 30% of their calories as carbs.
Volek (1996) has also noted that a higher carb to protein ratio diet correlated with higher T levels, and Anderson et al reported a low protein intake (10% total energy) was associated with higher levels of T compared to a diet higher in protein (44% total energy). Carbs also possibly reduce Sex Hormone Binding Globulin (SHBG) ratio, although this was not seen in obese men (Moran 2016). SHBG binds up Testosterone, preventing it from entering cells. Reducing the ratio of SHBG to T effectively increases your active, or ‘free’ Testosterone levels.
What is important to note here is that acutely increasing carbohydrate intake over a short time period will stimulate T levels to increase, or minimise the reduction in T levels noted with extended periods of intense exercise.
However, a chronic high carb diet over a long time period may well lead to the phenomenon noted above, where the HPG axis eventually fails to respond to yet more glucose.
In fact, the initial time period after carbohydrate or fat ingestion sees T levels decrease. Caronia (2013) noted a 25% decrease in average of T levels up to 2 hours post ingestion of 75g of glucose. A similar pattern has been noted with fat, with Volek (2001) observing a significant reduction in T and free T (22% and 23%) which remained below baseline for 8 hours. More work needs to be done to investigate this, but it seems likely that higher uptake of T at the receptor level of cells causes the blood levels to drop, rather than a reduction in steroidogenesis itself occurring. That is, ingesting Carbs or Fat may stimulate T to be utilised more by the body, and taken out of the blood into the cells, where a blood test won't detect it..
Several studies have documented the Cortisol minimising effects of carbohydrate ingested directly after intense exercise (Kazemzadeh 2012). This is another positive effect of Carbs for T levels, since Cortisol will reduce T synthesis.
- If you are lean (lets assume less than 15% body fat for a Man) then Carbs will stimulate T release
- Adequate Carb intake during and after intensive training will minimise Cortisol, and thus help T levels
T and Protein
Vegetarians are noted as having lower Testosterone than Carnivores. Several studies have documented this observation (Volek 1996). The red meat may well be part of the reason for this, but not because of its protein content.
Raben (1992) compared the effects of diet differing only in their source of protein in male athletes. Results showed a reduced resting and postexercise increase in T concentrations in athletes consuming protein derived mainly from vegetable sources compared to a diet with protein derived mainly from animal sources.
This may lead one to assume that the protein type affects T levels. Not necessarily, in fact, as seen in the Carbs section above, reducing the intake of Protein calories for Carb calories increases Testosterone. High protein diets have not been shown to increase T (Moran 2016). Two things are likely occurring here. Firstly, the composition of the fats associated with animal products increase T (See T and Fat below) and secondly, Soy products common in vegetarian diets have been demonstrated to reduce the Testosterone to Oestrogen ratio, and increase SHBG. (Habitio 2000)
This is a dilemma for Men trying to increase their lean body mass, as high protein intake, especially during calorie deficit, attenuate loss of lean body mass. (Henning 2014)
High protein diets are also favourable over high carb diets for their ability to improve glycaemic control.
- High protein intake itself does not increase T levels
- If dieting and using a high protein diet to minimise muscle tissue loss, eating enough saturated fat may help prevent lowering of T levels
- Read the section on Fat and T below for more information
T and Fat
Individuals consuming a diet containing 20% fat, compared with a diet containing 40% fat, have significantly lower concentrations of T (Volek 1996).
This makes sense if we consider that Testosterone is synthesised from Cholesterol, and Cholesterol is made from saturated fat. In fact, the transfer of cholesterol into the inner mitochondrial membrane is the rate limiting step of steroidogenesis in all body tissues. The Leydig cells in the testis use this cholesterol to ultimately produce Testosterone.
The type of fat in your diet is vitally important.
Testis cells in vitro have been shown to produce more T from saturated fat sources (Graciela 2009) and in human studies, it is possible to decrease T by modifying the diet to one higher in polyunsaturated fat to saturated fat (Hamamlainen EK 1983).
Vegetarians consume less fat, Saturated Fat, and eat a higher Polyunsaturated Fatty Acid (PUFA) / Saturated Fatty Acid (SFA) ratio compared with omnivores. Vegetarians also exhibit lower concentrations of T compared with omnivores. (Volek 1996).
If a reduction in fat is utilized is utilised as a dietary strategy, it may be possible to attenuate the drop in testosterone by maintaining adequate consumption of saturated fat (Volek 1996).
Not all PUFA’s are created equal though. Fish oil and Conjugated Linoleic Acid (CLA) have been shown to induce testosterone biosynthesis. These fats may alter receptor composition of testicular plasma membranes and there is also evidence that they upregulate the expression of genes involved in steroidigenesis (Macaluso 2013).
CLA is found in grass fed meats and diary products, but unless you consume a large amount of oily fish, supplementing with Fish Oil may be advisable.
Lastly, with regards to fat, a true high fat, low carb diet should be considered. This is known as a Ketogenic diet, whereby Carbs are kept so low, Kentone bodies are produced as an alternative fuel for the glucose hungry nervous system.
Few published studies investigate T levels in a truly ketogenic diet. But there are snippets of guidance.
A Ketogenic diet will increase Cortisol, especially in the adaptation phase of the diet (Langfort1996). Cortisol can inhibit T production and an increase in Cortisol production will skew the Cortisol to Free T ratio. This is undesirable.
What a longer investigation reveals however, is that such a diet quickly reduces body fat, and can maintain lean body mass and therefore strength if protein intake is high enough (Paoli 2012). Reducing carbs and body fat will make you more insulin and leptin sensitive. So cycling in and out of ketosis, or using ketosis to lose body fat periodically, could be useful to boost T levels long term.
Lastly, Volek (2002) concluded that a carbohydrate-restricted diet resulted in a significant reduction in fat mass and a concomitant increase in lean body mass in normal-weight men, which may be partially mediated by the reduction in circulating insulin concentrations. No changes in T or Free T were noted.
It is possible that once a person is adapted to a ketogenic diet, their T levels stabilise at normal levels.
- Adequate saturated fat intake is essential to increase or maintain T levels.
- Too much Polyunsaturated fat to Saturated Fat will decrease T levels
- Fish Oil and CLA may help T levels and can be easily supplemented if lacking in the diet.
- Ketogenic diets likely increase Cortisol in the initial phase
- The long term effects of Ketogenesis on T are unknown (at least, we couldn't find any!)
Total Calorie Effects and T
Severe calorie restriction lowers testosterone (Marniemi 1984). This may not be the case for obese Men, in whom reduced calorie intake appears to affect the HPG axis differently to normal weight Men (Röjdmark 1989). If you are already reasonably lean, and body fat reduction is your goal, a calorie reduction of 15% has been shown to not reduce T levels (Garrel 1984)
In studies of weight loss rates, weekly losses of 1 kg over 4 weeks resulted in a 5% decrease in bench press strength and a 30% greater reduction in testosterone levels in strength training women, compared to 0.5kg per week losses (Helms 2014)
Over eating in excess to maximise ‘gains’ may moderately increase T levels in the short term, but increasing body fat will ruin T levels, especially in a chronic setting. We have written before about the effects of too much body fat on the HPG axis. In lean subjects, Insulin and Leptin stimulate the HPG axis to produce more T. Chronic high levels of insulin from long term excessive food intake, and high leptin levels released from excess body fat, desensitise the HPG which stops responding to these hormones (Soderberg 2001). Thus, over eating to boost T is a strategy to be used short term and relatively infrequently.
- If dieting, do not reduce calories by more than 15% per day
- Slower weight loss will impact T levels less
- Acute overeating may increase T, but chronic overeating may eventually decrease T
Fasting and T
Intermittent fasting is still a relatively new concept, but eating nothing is intuitively likely to decrease T levels, since crash dieting does just that. Sadly there is a paucity of literature to guide us here.
The theory stacks up in Monkeys, with a significant decrease in T after just 24 hours of fasting (Medhamurthy 2007). It is probable the effect is similar in humans. Sartorius (2012) observed that short term overnight fasting increases T levels, although their methodology may have failed to account for the fact that simply eating breakfast may reduce T levels in blood, and therefore account for the reduction in T noted in non-fasted states. Mattson (2016) observed alternate days fasting increased T in Male rats.
Interestingly, it is possible that fasting improves sensitivity of androgen receptors to T. Men have demonstrated a 180% increased testosterone response to fasting (Röjdmark 1989).
What is clearer, is that even a single bout of fasting improves insulin sensitivity (Patterson RE and Sears 2017). As we have observed, improving Insulin sensitivity is key to long term T levels.
For now, lack of solid research based guidances means common sense must lead the way if Intermittent Fasting is a strategy you use and you also want to maintain great T levels. As such, the 16:8 method championed by Martin Berkhan seems sensible. 16 hours is enough time to bask in high circulating T levels (especially observed a.m.) before they drop after eating, and probably not enough time to have T crash because your reproductive axis thinks you are heading for lean times.
- Fasting for too long will likely drop your T levels
- Fasting may increase your sensitivity to T
- Until more research is done, a 16:8 pattern of fasting is sensible for those wanting to keep T levels high
Planning your Macros
Based on what we have discovered, a 40:30:30 split of Carbs:Protein:Fat is a good place to begin for high T levels.
Ensure adequate Carb intake, especially during periods of heavy training. Eating most of your Carbs around training will maximise their effects
On non-training days, upping fat intake to around 40% may help to boost T levels further. Whatever the amount of fat in your diet, it should be comprised of mainly Saturated fats if optimal T levels are your goal. Supplementing with Fish Oil and CLA may boost this further.
The ratio of saturated fats to polyunsaturated fats is important for T levels. Minimise polyunsaturated fats by reducing intake of processed foods and grain based foods.
Vegetarians seeking to boost their T levels could utilise dairy based saturated fats like butter or monounsaturated fats like olive oil or avocado to achieve this.
A low carb diet is a useful way of quickly reducing body fat levels in overweight Men. Restoring Insulin and Leptin sensitivity is essential for healthy T levels.
Protein eaten at the expense of Carbs and Fats may, if you are already lean, prevent optimal T levels. This is a trade off, as during dieting phases, high protein intake will spare lean tissue loss. Again, adequate saturated fat intake might help to keep T high.
Fasting is an interesting way to manage your macronutrient intake. Try a 16:8 fasting to feeding split and
Lastly, tracking your T levels, especially if you suspect they may be low, is essential. This can done via several online companies and gives you a base line, an objective marker, from which to titrate your variables and re-test.
There you have it, a deep dive into how your Macros can impact your T levels. Now, I'm off to get some grass fed beef and sweet potatoes.
Please get in touch and let us know how you get on with your T optimisation!
Anderson KE et al (1987) Diet-Hormone interactions: protein/carbohydrate ratio alters reciprocally the plasma levels of testosterone and cortisol and their respective binding globulins in man, Life Sci, 40:1761-1768
Caronia LM et l (2013) Abrupt decrease in serum testosterone levels after an oral glucose load in men: implications for screening hypogonadism, Clin Endo, 78 291-296
Garrel DR et al (1984) Hormonal changes in normal men under marginally negative energy balance. American Journal of Clinical Nutrition. 39(6):930-6
Graciela HE et al (2009) Influence of Commercial Dietary Oils on Lipid Composition and Testosterone Production in Interstitial Cells Isolated from Rat Testis, Lipids, 10.1007/s11745-008-3277-z
Habitio RC et al (2000) Effects of replacing meat with soybean in the diet on sex hormone concentrations in healthy adult males, British Journal of Nutrition, 84, 557-563
Hamalainen EK et al (1983) Decrease of serum total and free testosterone during a low-fat high fibre diet, Journal of Steroid Biochemistry, March, vol 18, issue 3, 369-370
Helms ER et al (2014) Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation, Journal of the international society of sports nutrition, 11:20
Kazemzadeh Y et al (2012) Effects of Carbohydrate-Protein Intake During Exercise on Hormonal Changes and Muscular Strength after 12-weeks Resistance Training, J Basic Appl Sci Res, 2(6)5945-5951
Lane AR et al (2010) Influence of the dietary carbohydrate intake on the free testosterone:cortisol ratio responses to short-term intensive exercise training, Eur J Appl Physiol, 108:1125:1131
Langfort J et al (1996) Effect of low carbohydrate ketogenic diet on metabolic and hormonal responses to graded exercise in men, J Phys and Pharm: Official Journal of the Polish Physiological Society, 47(2):361-371
Macaluso F et al (2013) Do fat supplements increase physical performance? Nutrients, 5:509-524
Marniemi J et al (1984) Metabolic changes induced by combined prolonged exercise and low-calorie intake in man. European Journal of Applied Physiology & Occupational Physiology. 53(2):121-127
Matson MP et al (2016) Impact of intermittent fasting on health and disease processes, Ageing Research Reviews, http://dx.doi.org/10.1016/j.arr.2016.10.005
Medhamurthy R et al (2007) Short-term fasting leads to inhibition of responsiveness to LH-stimulated testosterone secretion in the adult male bonnet monkey, Am J Primatol, Jul;69(7):791-801
Moran LJ et al (2016) Long Term Effects of a randomised controlled trial comparing high protein or high carbohydrate weight loss diets on testosterone, SHBG, Erectile and Urinary Function in Overweight and Obese Men, PLOS ONE, 10.1371/jornal.pone.0161297
Osuna JA et al (2009) Relationship between BMI, Total Testosterone, Sex Hormone-Bnding Globulin, Leptin, Insulin and Insulin Resistance in Obese Men, Arch Ando, 52:355-361
Patterson RE and Sears DD (2017) Metabolic Effects of Intermittent Fasting, Annual Review of Nutrition, 37:371-93
Paoli A et al (2012) Ketogenic diet does not affect strength performance in elite artistic gymnasts, Journal of the International Society of Sports Nutrition, 9:34
Pasquali R et al (1995) Insulin Regulates Testosterone and Sex Hormone-Binding Globulin Concentrations in Adult Normal Weight and Obese Men, J Clin Endo and Met, 80(2): 645-658
Pitteloud N et al (2005) Increasing Insulin Resistance is Associated with a Decrease in Leydig Cell Testosterone Secretion in Men, J Cin Endo and Met, 90(5):2636-2641
Raben A et al (1992) Serum Sex Hormones and endurance performance after a lacto-ovo vegetarian and a mixed diet, Med Sci Sports Exercise 24: 1290-1297
Röjdmark S et al (1989) Pituitary-testicular axis in obese men during short term fasting, Acta Endo (Copenh), Nov, 121(5): 727-732
Roland AV and Moenter SM (2011) Regulation of gonadotropin-releasing hormone neurons by glucose, Trends Endocrinol Metab, 22(11):443-449
Sartorius G et al (2012) Serum Testosterone, dihydrotestosterone and estradiol concentrations in older men self-reporting very good health: the healthy man study, Clin Endo, 77, 755-763
Söderberg S et al (2001) A strong association between biologically active testosterone and leptin in non-obese men and women is lost with increasing (central) adiposity, Int J Obes Relat Metab Disord, Jan;25(1):98-105
Traish AM et al (2009) The Dark Side of Testosterone Deficiency: II Type 2 Diabetes and Insulin Resistance, J of Andro, 30(1): 23-32
Volek JS et al (1996) Testosterone and cortisol in relationship to dietary nutrients and resistance exercise, Diet and Hormones, 49-53
Volek JS et al (2001) Effects of a high-fat diet on postabsorptive and postprandial testosterone responses to a fat-rich meal, Metabolism, Vol 50, 11; 1351-1355
Volek JS et al (2002) Body Composition and hormonal responses to a carbohydrate-restricted diet, Metabolism, Jul:51(7) 864-70