Does Bulking Increase Testosterone? What Science Says

You probably are aware of the links between diet and hormone balance. But does this mean that a calorie surplus directly affects testosterone levels?

Having studied how nutrition interacts with our bodies, I can give you some science-backed answers on the topic.

So, does bulking increase testosterone? Yes, bulking can alter testosterone levels in some people, but it depends on the number of calories and macros that you eat. Research suggests that if you want to avoid low testosterone levels, then a caloric surplus is preferable over a caloric deficit, with fat intake playing a key role in testosterone production.

Knowing whether your testosterone levels are balanced is important, especially if you want to avoid facing low levels that can cause loss of muscle and strength. 

In this article, I will talk about current research and will share some useful nutrition tips to support you in your caloric surplus.

Key Takeaways

  • Research on the topic of eating a surplus of calories to increase testosterone levels is limited in athletes. Because of this, some evidence refers to calorie deficits reducing testosterone.
  • Any quantity of calories you eat affects testosterone levels. To avoid low testosterone levels, evidence indicates that you need to include enough calories and fat in your diet.
  • Keeping these 2 tips in mind will help you maintain a good balance in testosterone levels: check that your surplus is correct to ensure you are eating enough calories, and aim to eat ~ 20% of total calories from fat. 

Do More Calories Increase Testosterone?

Research is quite broad around this topic. You have to delve into it to notice that nuances are often not mentioned.

For example, I recently read a blog article that stated “more calories increase testosterone levels”. That article made a generic claim based on a study done on a group of nonathletes. 

As such, you should be careful about the information you base nutritional assumptions on. 

It is difficult to know the precise quantity of calories you need for testosterone to increase, considering there is not much research available on a surplus of calories and testosterone.

Many studies in fact refer to a deficit of calories rather than a surplus, clearly indicating that eating fewer calories or below your maintenance calories lowers testosterone, causing a loss in weight, muscle mass, and strength to name a few.

As eating fewer calories negatively impacts testosterone, it makes sense to think that eating more calories probably has the opposite effect on testosterone. 

So, one could assume that eating more calories increases testosterone.

In this instance, my recommendation would be to reformulate the question based on the available evidence. 

Ask yourself: does the quantity of calories you eat affect testosterone? 

Research on Calorie Surplus & Testosterone Levels

Knowing how to distinguish facts from fiction and interpret information correctly is important in the context of sports nutrition, particularly calories and testosterone.

“Testosterone changes in men appear mostly related to energy availability (body fat content and energy balance)”

Eric R. Helms – International Society of Sports Nutrition

The above quote simply means that testosterone balance depends on energy (calorie) balance. 

In the instance of an athlete during a bulking phase, energy balance is a result of a caloric surplus, adequate macros, testosterone, and training. 

As such, I will discuss two relevant topics.

Topic 1 – Any Amount of Calories Affects Testosterone Levels

There is a lot of evidence suggesting that testosterone levels are linked with the calories and nutrients you eat.  

In the context of strength and physique sports, calorie deficits have been linked to low testosterone:

  • One study looked at the hormonal effects of contest preparation of a male bodybuilder and found a 72% decrease in testosterone. The subject had been on a strict calorie deficit for months. This meant that testosterone levels were low because of the calorie deficit.
  • The same study saw that testosterone levels quadrupled during the recovery period after the contest, in which the bodybuilder ate a surplus of 1000 calories to reach back at his baseline. Despite this, a large surplus of calories along with weight gain improved his testosterone.

There is also other research that indicates that a calorie surplus improves testosterone, however, this is in sedentary subjects.

  • One study looked at the effects of diet on hormones in male twins showing a link between a surplus of calories and higher testosterone. Despite this positive effect, you need to consider that the subjects were not athletes or exercising.

Key takeaway: If you eat enough calories or a surplus, your testosterone levels will most likely be balanced. If you want to reduce the chances of having low testosterone, then you should avoid being in a caloric deficit.

Topic 2 – The Number of Calories From Fat Influences Testosterone Levels

A lot of research suggests that higher fat intakes affect testosterone positively.

  • One study looked at the differences between athletes eating a diet containing more fat (40%) and less fat (20%). The ones eating more fat had higher testosterone levels. 
  • 2 studies on nonathletes looked at diets higher in fat (40% and 33% of total calories) and lower in fat (20% and 14% of total calories). Both studies saw large reductions in testosterone levels with the low-fat diets.   

Key takeaway: If an adequate part of your calorie surplus comes from fat, it is likely that your testosterone will be balanced. Despite the evidence supporting higher fat intake and testosterone, fat is not the optimal fuel source for strength and physique athletes and should be consumed in moderate amounts.

Tips for Increasing Testosterone Levels With a Caloric Surplus

tips for increasing testosterone levels with a caloric surplus

If you train regularly whilst consistently hitting your caloric surplus and macro targets, then you are on the right track for having balanced testosterone levels. 

As such, here are some tips which aline with the previous points:

Tip 1 – Ensure your caloric surplus is correct to minimize slowing down the production of testosterone

To know whether you are eating enough calories in your surplus, you need to check that your surplus is correct. 

Double-check this at the start of the bulking phase and when it is time to reassess your targets. This way you will be sure that you are eating enough and that testosterone levels in your body are balanced/increased. 

You can refer to my article “How Big Should My Calorie Surplus Be?” if you want to know more about reassessing your surplus. 

Tip 2 – Ensure your fat target does not go below the recommended  guidelines for athletes

The recommendations for fat intake for power/strength athletes is 20-35% of total calories. This range is advised to maintain testosterone balance. 

So, if you are a powerlifter, aim to keep fat intake within this range. 

If you are a competitive bodybuilder the recommendation changes slightly to 15-20% of total calories. 

So, if you want to avoid a reduction in testosterone, don’t go below this range when calculating your fat macros.

Other Bulking Resources


Bishop DT, Meikle AW, Slattery ML, Stringham JD, Ford MH, West DW. The effect of nutritional factors on sex hormone levels in male twins. Genet Epidemiol. 1988;5(1):43-59. doi: 10.1002/gepi.1370050105. PMID: 3360302.

Zamir, A.; Ben-Zeev, T.; Hoffman, J.R. Manipulation of Dietary Intake on Changes in Circulating Testosterone Concentrations. Nutrients 2021, 13, 3375.

Helms, E. R., Aragon, A. A., & Fitschen, P. J. (2014). Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. Journal of the International Society of Sports Nutrition, 11, 20.

Pardue A, Trexler ET, Sprod LK. Case Study: Unfavorable But Transient Physiological Changes During Contest Preparation in a Drug-Free Male Bodybuilder. Int J Sport Nutr Exerc Metab. 2017 Dec;27(6):550-559. doi: 10.1123/ijsnem.2017-0064. Epub 2017 Aug 3. PMID: 28770669.

Bishop DT, Meikle AW, Slattery ML, Stringham JD, Ford MH, West DW. The effect of nutritional factors on sex hormone levels in male twins. Genet Epidemiol. 1988;5(1):43-59. doi: 10.1002/gepi.1370050105. PMID: 3360302.

Dorgan JF, Judd JT, Longcope C, Brown C, Schatzkin A, Clevidence BA, Campbell WS, Nair PP, Franz C, Kahle L, Taylor PR. Effects of dietary fat and fiber on plasma and urine androgens and estrogens in men: a controlled feeding study. Am J Clin Nutr. 1996 Dec;64(6):850-5. doi: 10.1093/ajcn/64.6.850. PMID: 8942407.

Volek, J. S., Kraemer, W. J., Bush, J. A., Incledon, T., & Boetes, M. (1997, January 01). Testosterone and cortisol in relationship to dietary nutrients and resistance exercise. Retrieved from

Mota, Jacob A. MS1,2; Nuckols, Greg MA1; Smith-Ryan, Abbie E. PhD1,2,3. Nutritional Periodization: Applications for the Strength Athlete. Strength and Conditioning Journal 41(5):p 69-78, October 2019. | DOI: 10.1519/SSC.0000000000000488

Lambert CP, Frank LL, Evans WJ. Macronutrient considerations for the sport of bodybuilding. Sports Med. 2004;34(5):317-27. doi: 10.2165/00007256-200434050-00004. PMID: 15107010.

About The Author

Giulia Rossetto

Giulia Rossetto is a qualified Dietitian and Nutritionist. She holds a Masters in Human Nutrition (University of Sheffield, UK) and more recently graduated as a Dietitian (University of Malta). Giulia aims to translate evidence-based science to the public through teaching and writing content. She has worked 4+ years in clinical settings and has also published articles in academic journals. She is into running, swimming and weight lifting, and enjoys spending time in the mountains (she has a soft spot for hiking and skiing in the Italian Dolomites).

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