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Can Intermittent Fasting Boost Testosterone?

In order to make the best gains possible, you need to train hard and eat well. To optimize your physique you need to focus on ways to elevate your testosterone. By doing so you’ll increase your muscle mass, strength and improve your body composition too.

One of the most current and popular dietary plans around is that of intermittent fasting. Not only has it been shown to improve health, it can improve also improve aesthetics too.

In this article we’ll take a detailed look at this dietary approach and tell you all you need to know about fitting it into your lifestyle. Can it boost testosterone levels? Read on to find out more. 

Here’s what we’ll cover:

  • What is intermittent fasting?
  • Does fasting improve health?
  • Can intermittent fasting boost testosterone?

What is Intermittent Fasting?

Intermittent fasting (IF) is a dietary intervention or pattern. To sum it up in the simplest terms possible it is the process of purposely skipping meals in order to improve body composition. It involves cycling periods of normal, regular eating with periods of food abstinence.

There are no hard and fast rules about how long you should fast for, but it is a very different approach to a ‘daily restrictive diet’ approach where food is reduced by 20-40% every day. By contrast it is much easier to maintain.

Common practice involves restricting calories for 1-3 days per week whilst being able to eat freely on non-fast days [1]. You can either fast on consecutive days or alternate based on preference.

Typically, fasting days restrict calories by at least 75% with many opting for a total fast for periods of 16 hours up to full days at a time. During these fasting days the only nourishment allowed is calorie free – water, coffee and tea are commonly used to keep hydrated.

Fasting has been part of our ancestry since ancient times, and many religious groups still choose to fast for long periods. Muslims fast from dawn until dusk during the month of Ramadan and other groups such as Buddhists and Hindus choose to restrict eating on designated days of the year too [2].


Key Point: Intermittent fasting involves cycling periods of normal eating with periods of food abstinence.

Does Intermittent Fasting Improve Health?

Clinical trials have found that IF helps to burn fat and reduce body mass. This has been attributed to the fact that less meals are eaten over a given week. It also means that a calorie deficit is much easier to achieve.

Beneficial results have been seen in a number of metabolic diseases too. Diabetes type 2 in particular appears to be improved, as limiting meal frequency reduces blood sugar and improves insulin sensitivity [1]. Likewise, fasting has also been shown to improve the inflammatory markers associated with cardiovascular disease [3].

Lastly, it appears that IF can also help to protect brain health. Studies have shown that reduced oxidative stress coupled with improved blood sugar and insulin resistance, can nourish nerve cells within the brain. It has also been found to increase levels of the hormone brain-derived neurotrophic factor (BDNF) [4] – a neurotrophin protein associated with mood regulation.


How Does IF Affect Testosterone?

Not only has IF been shown to improve overall health, there is also evidence to show that intermittent fasting can increase testosterone levels too. 

Published in Acta Endocrinolgica, Röjdmark et al [5] found that IF resulted in favorable changes to the pituitary-testicular axis in a group of obese men – basically the link between the brain and testes.

During the study, non-obese volunteers reported a 67% increase in luteinizing hormone – an important precursor hormone to testosterone. More importantly they also reported a massive increase in testosterone of 180% – this was after a relatively short-term, 56-hour fast.

Interestingly, the same study was then repeated using obese volunteers – luteinizing hormone only increased by 26% and there was no significant change in T levels at all.

The hormonal system is a complex array of different chemical messengers – some work together and some work like the gas and break of a car – as one goes up, the other comes down. Leptin – the hormone responsible for regulating energy balance – most certainly puts the brakes on T production [6]. As leptin levels creep up, testosterone begins to decrease.

Leptin has been found to be inversely related to body fat levels too. When you eat something, leptin levels increase in order to tell your brain you are getting full – a process called satiety.

During periods of IF, leptin levels have been found to decrease in a process called down regulation. Decreased leptin has been found to stimulate the release of testosterone, providing yet another reason why intermittent fasting can be beneficial for T production [7].

Lastly, a study published in the Journal of Clinical Investigation [8] reported that IF over a 24-hour period boosted growth hormone by a massive 1300% in women and even bigger 2000% in men. 

Growth hormone and testosterone both exhibit anabolic properties that help to stimulate muscle growth. T can help promote the growth hormone response, and growth hormone itself helps to ‘correct’ T levels, so they work very much synergistically.


Key Point: Research shows that intermittent fasting can boost testosterone as growth hormone levels. Not only that, it can also improve leptin regulation which contributes to a better body composition.


Intermittent fasting is a dietary pattern that uses cycles of free and restricted eating in order to improve health and body composition. It has been found to improve brain health, metabolic disease markers, obesity and cardiovascular disease risk factors too.

Research suggests that not only is intermittent fasting beneficial for health, it can boost testosterone and other associated anabolic hormones too. Whilst there isn’t a tremendous amount of research to draw upon, the studies that are available appear to be promising. It is definitely a method to try.

Ultimately, intermittent fasting seems like an effective method of boosting testosterone. Not only that, it controls other hormones that can indirectly benefit T levels too.

All of the above studies used short-term fasting and this is something we’d recommend – either by implementing alternate day fasting or focusing on 2-3 fasts per week. As with any changes to your diet though you should always seek medical advice first, particularly if you have an underlying medical condition.


  1. Barnosky, AR et al. Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational Res. 2014; 164(4): 302-311
  2. Longo, VD et al. Fasting: Molecular Mechanisms and Clinical Applications. Cell Metab. 2014; 19(2): 181-192
  3. Brown, JE et al. Intermittent fasting: a dietary intervention for prevention of diabetes and cardiovascular disease? Br J Diabetes Vascular Disease. 2013; 13(2): 68-72
  4. Duan, W et al. Dietary restriction normalizes glucose metabolism and BDNF levels, slows disease progression, and increases survival in huntingtin mutant mice. PNAS. 2003; 100(5)
  5. Röjdmark, S et al. Pituitary-testicular axis in obese men during short-term fastingActa Endocrinol (Copenh). 1989; 121(5): 727-32
  6. Luukkaa, V et al. Inverse correlation between serum testosterone and leptin in menJ Clin Endocrinol Metab. 1998; 83(9): 3243-6
  7. Weigle, DS et al. Effect of fasting, refeeding, and dietary fat restriction on plasma leptin levels. J Clin Endocrinol Metab. 1997; 82(2): 561-5
  8. Ho, KY et al. Fasting enhances growth hormone secretion and amplifies the complex rhythms of growth hormone secretion in man. J Clin Invest. 1988; 81(4): 968–975