Does Intermittent Fasting Increase Testosterone?

Written by: Pard Bharaj



Time to read 7 min


Intermittent fasting is more than a dietary fad; it's a powerful tool for those looking to take control of their health and physique. By cycling between periods of eating and fasting, this approach challenges the conventional wisdom of three meals per day. It offers a straightforward path to improved health without the need to obsess over every calorie. 

The benefits of intermittent fasting extend far beyond simple weight loss:

  • Weight Management: Streamlines calorie control, leading to effective weight loss and body fat reduction without the need for complex diets.

  • Metabolic Boost: Enhances metabolic health markers, including blood sugar levels and cholesterol, reducing the risk of chronic diseases.

  • Cognitive Enhancement: Supports brain health, potentially improving focus, memory, and protecting against age-related decline.

  • Longevity: Early research suggests a link between fasting and increased lifespan, pointing to a deeper connection between meal timing and overall health.

However, can intermittent fasting improve testosterone levels? In this article we will explore a number of scientific studies to find an answer to this question.

Key Takeaways From This Article: 

  • Intermittent Fasting (IF): While IF offers health benefits like weight loss and metabolic improvement, its impact on testosterone levels is complex and requires more research.
  • Testosterone Impact: Initial studies suggest IF might lower testosterone levels in men, contrary to some expectations.

  • Study Findings: Research on humans and animals indicates a potential decrease in testosterone with IF, highlighting the need for a balanced approach and further investigation.

  • Health Recommendations: For those concerned about testosterone levels, focusing on exercise, a balanced diet, and lifestyle adjustments is recommended.

Understanding Testosterone and its Types:

Testosterone is the cornerstone of male health, driving everything from muscle mass and fat distribution to libido and mood. It's not just about having enough; it's about understanding the different forms testosterone takes in your body and their impact on your health and performance.

Primarily produced in the testicles, testosterone is the fuel behind male sexual development and function. It's the muscle builder, the mood enhancer, and the energy booster. Testosterone exists in several forms in your bloodstream, each with its own role to play.

Here are the different types of testosterone:

  • Free Testosterone: Think of free testosterone as the unchained, active form ready to be used by your body. It's what gets immediately to work on your libido, muscle growth, and energy levels. Despite being a small fraction of your total testosterone, its availability is crucial for your body's immediate needs.
  • Bound Testosterone: Most of your testosterone is bound to proteins like SHBG (sex hormone-binding globulin) and albumin. Here's the breakdown:
    • SHBG-Bound Testosterone: Locked up and out of reach for your body's tissues, and not immediately usable.
    • Albumin-Bound Testosterone: Easily accessible and ready to be converted into free testosterone when your body calls for it.
  • Bioavailable Testosterone:  Combining free testosterone and albumin-bound testosterone, this is the portion that's ready for action. It's what your body can use on the spot for muscle building, maintaining your sex drive, and ensuring your energy levels are up to par.

Does Intermittent Fasting Increase Testosterone. Exploring Scientific Studies:

In this section I will explain and summarise 3 of the main scientific studies to see if intermittent fasting can positively affect testosterone levels. I should mention from the beginning that there weren't many scientific studies specifically exploring if intermittent fasting increases testosterone levels and more research is required in this area:

Study 1: Impact of Time-Restricted Feeding on Trained Men

  • What's Tested: Effects of eating within an 8-hour window on testosterone and muscle strength.

  • Participants: 34 weightlifting men divided into Time-Restricted Feeding (1 p.m. to 8 p.m.) and Normal Diet groups.

  • Findings: TRF group saw a decrease in testosterone levels but maintained muscle mass and strength.

  • Source: Full Study


Time-restricted feeding (TRF) lowers testosterone in men engaging in resistance training without affecting muscle strength or mass. This suggests meal timing impacts hormonal health, though TRF remains effective for fat loss and muscle maintenance.

The image captures a male athlete in mid-sprint, with his body leaning forward in a powerful motion. He is wearing sprinting attire and shoes, indicative of a runner or sprinter in a race or during training.

Study 2: Intermittent Fasting's Influence on Reproductive Hormones

  • Study Source: Full Study
  • Focus: Examining intermittent fasting's effects on hormones like testosterone in men and women.
  • Approach: Reviewed studies on IF's hormonal impacts, including time-restricted eating and the 5:2 diet.
  • Results: Men experienced reduced testosterone levels; women saw hormonal changes that could benefit conditions like PCOS.


Intermittent fasting (IF) decreases testosterone in men but may benefit women with obesity by altering reproductive hormones, potentially aiding in PCOS management. The varied effects highlight the need for further study on IF's hormonal impacts.

The image displays the word "Testosterone" in green letters against a beige background, which is partially revealed by a torn red paper overlay.

Study 3: Intermittent Fasting's Effects on Young Male Rats

  • Objective: Explore an every-other-day fasting diet's impact on testosterone in rats.
  • Method: Male rats fasted every other day for 12 weeks, with testosterone, weight, and glucose monitored.
  • Key Outcome: Significant testosterone reduction, alongside decreases in body weight and blood glucose.
  • Source: Full Study.


In young male rats, every-other-day fasting significantly reduces testosterone, alongside body weight and glucose levels, indicating IF's broad metabolic and hormonal effects. This suggests potential reproductive health risks with IF practices.

The image shows a round wooden plate on a turquoise background with a knife and fork crossed over the center of the plate, resembling a clock

Final Conclusion: Does Intermittent Fasting Increase Testosterone?

Personally, adopting the 16:8 intermittent fasting (IF) method has been a game-changer for me in terms of health and performance. This disciplined approach, fasting for 16 hours followed by an 8-hour nutritional intake window, has delivered undeniable benefits. It's sharpened mental clarity, enhanced fat loss, and significantly improved metabolic health. 

However, regarding testosterone levels—a fundamental aspect of masculine health—the data indicates that intermittent fasting (IF) may not offer the support previously assumed. Despite its numerous benefits, IF appears to have the potential to reduce testosterone levels, contrary to enhancing them. This insight necessitates a more detailed examination of IF's effects, particularly for individuals focused on improving testosterone levels.

Frequently Asked Questions:

Is intermittent fasting recommended for improving reproductive health?

The impact of IF on reproductive health varies between genders. While it may offer benefits for women with certain conditions like PCOS, men might experience a decrease in testosterone levels, suggesting the need for a balanced approach and further research.

Are there any potential risks associated with intermittent fasting regarding hormonal balance?

Yes, while IF has several health benefits, it can potentially lower testosterone levels in men and may have varied effects on reproductive hormones, highlighting the importance of considering individual health goals and conditions when practicing intermittent fasting.

How can I naturally increase testosterone levels?

Exercise and Physical Activity:

  • Strength Training and HIIT: Boost testosterone with regular strength training and high-intensity interval training.

  • Aerobic Exercise: Support overall hormonal health with daily aerobic activities.

Dietary Adjustments:

  • Balanced Diet: Focus on whole foods, including lean proteins, healthy fats, and a variety of vegetables and fruits.

  • Zinc and Vitamin D: Incorporate foods high in zinc and vitamin D to aid testosterone production.

  • Limit Phytoestrogens and Alcohol: Moderate intake of soy, flaxseed, and alcohol to manage estrogen levels.

Lifestyle Changes:

  • Quality Sleep: Aim for 7-9 hours of sleep per night to prevent testosterone decline.

  • Stress Management: Use meditation, yoga, or hobbies to reduce stress.

  • Healthy Weight: Obesity is linked to lower testosterone, so maintaining a healthy weight is crucial.

  • Reduce Exposure to Estrogen-like Chemicals: Choose BPA-free products to minimise exposure to harmful chemicals.

Sunlight Exposure:

  • Vitamin D Boost: Regular midday sunlight exposure can increase vitamin D levels, supporting testosterone production.

Herbal Supplements:

  • Ashwagandha, Fenugreek, and Ginger: These may support testosterone levels but consult a healthcare professional before starting.

Enjoyment and Social Interaction:

  • Leisure and Socialising: Engage in activities and spend time with loved ones to reduce stress and support hormonal balance.

Avoid Toxins:

  • Why: Certain toxins, including pesticides, parabens, and other chemicals found in some personal care products, can disrupt hormonal balance and function as endocrine disruptors. These substances can mimic or interfere with the body's natural hormones, including testosterone, leading to potential decreases in hormone levels and adverse effects on reproductive health.

  • Action: Opt for organic foods when possible, use natural personal care products, and reduce exposure to household chemicals to minimise the risk of hormonal disruption.

Related Readings

References and Further Reading:

  1. The study titled "Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males" was authored by Tatiana Moro, Grant Tinsley, Antonino Bianco, Giuseppe Marcolin, Quirico Francesco Pacelli, Giuseppe Battaglia, Antonio Palma, Paulo Gentil, Marco Neri, and Antonio Paoli. It is published in the Journal of Translational Medicine, Volume 14, Article number: 290 (2016). Full Study.
  2. The study titled "Effect of Intermittent Fasting on Reproductive Hormone Levels in Females and Males: A Review of Human Trials," authored by Sofia Cienfuegos, Sarah Corapi, Kelsey Gabel, Mark Ezpeleta, Faiza Kalam, Shuhao Lin, Vasiliki Pavlou, and Krista A. Varady from the Department of Kinesiology and Nutrition at the University of Illinois at Chicago. It was published in the journal Nutrients in 2022. Full Study.
  3. The study titled "Intermittent fasting dietary restriction regimen negatively influences reproduction in young rats: a study of hypothalamo-hypophysial-gonadal axis". Authored by Sushil Kumar and Gurcharan Kaur from the Department of Biotechnology, Guru Nanak Dev University, Amritsar, Punjab, India. It was published in PLoS One in 2013. The DOI for this study is 10.1371/journal.pone.0052416. Full Study.
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Author: Pard Bharaj

I am a dedicated researcher with nearly a decade of experience in investigating health best practices. My journey in the health and wellness field has been driven by a passion for understanding and sharing the most effective ways to maintain and improve health. Over the years, I have delved into a wide range of topics, constantly seeking out the latest research and insights. My commitment is to provide well-researched, accurate, and trustworthy information to help readers make informed decisions about their health.

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