How Intermittent Fasting Impacts Testosterone
Testosterone is the powerful reproductive hormone that helps develop male sexual characteristics and plays a role in bone and muscle mass, red blood cell production, and fat distribution. Lower levels of this important steroid hormone lead to a reduced sex drive, weight gain, moodiness, thinner bones, and more.
A range of factors impact your reproductive hormones, from stress to chronic illness. What about intermittent fasting? You’ve probably heard about the many benefits of intermittent fasting, but how does intermittent fasting impact testosterone?
What Is Intermittent Fasting?
Intermittent fasting is the practice of fasting or refraining from eating for a specific time period. When you stop eating food, you give your digestive system a break. Most people fast overnight while they sleep and break their fast in the morning with breakfast. Intermittent fasting involves fasting and feeding windows where you refrain from eating at certain intervals.
Whether you’re practicing short-term intermittent fasting between 12-24 hours or extended fasting for 24 hours or longer, fasting has been proven to yield a range of health benefits. Some of these health benefits include hormone regulation, body composition, stabilizing blood glucose and ketone levels, and improving the gut microbiome (the healthy ecosystem of bacteria and microorganisms in your gut).
How Does Intermittent Fasting Impact Testosterone?
While sugar-loaded American diets can have a negative impact on your testosterone levels, intermittent fasting (IF) can actually increase testosterone. With so many people deficient in testosterone, intermittent fasting is one way to boost those levels. Here’s how IF can boost testosterone for men and women.
Luteinizing Hormone
Certain hormones are involved in testosterone synthesis. One of these hormones is luteinizing hormone (LH), which triggers the release of testosterone from the ovaries or testes. Intermittent fasting stimulates the production of LH, resulting in a rise in testosterone. [1]
For example, one study looked at intermittent fasting in healthy men, and the researchers documented an improvement in fasting LH of almost 67%, which improved overall testosterone by an impressive 180%. [2]
Insulin Hormone
Just like the ketogenic diet, intermittent fasting lowers your need for the digestive hormone called insulin. Insulin is the fat-storage hormone that tells your body to hold on to fat and prevents your blood sugar from climbing dangerously high by scuttling sugar into your cells. Insulin can also inhibit testosterone production in your body. Studies show that consuming calories (particularly packaged, processed, and sugary calories) brings a decrease in testosterone in males, so it makes sense that when you refrain from eating, the opposite happens. [3]
Research reveals that fasting can improve insulin sensitivity and testosterone levels. [4]
Adiponectin Hormone
Fasting stimulates adiponectin production—a protein hormone involved with lipid and glucose metabolism. When you fast, you bring adiponectin to optimum levels, which improves insulin sensitivity and testosterone levels. [5]
Insulin resistance and a poor metabolism impede reproductive hormone production, and fasting helps optimize your metabolism and lower your risk of insulin resistance (a condition where your cells become resistant to the insulin hormone).
Leptin Hormone
The leptin hormone regulates hunger, food intake, and energy expenditure, and makes you feel full. Leptin prevents you from feeling hungry largely by acting on the hypothalamus of your brain. [6]
An interesting study showed that long periods of intermittent fasting reduced the hormone leptin in the body, which also resulted in a rise in testosterone production. [7]
Promotes Weight Loss
Losing excess body fat and maintaining a healthy body weight is another way to increase testosterone, and intermittent fasting has been proven effective for weight loss, particularly when paired with a high-fat ketogenic diet. With your metabolism in fat-burning mode, testosterone production typically increases.
Promotes Detoxification
Fasting pushes your body to burn your fat stores for energy, releasing chemicals from your fat deposits. Many toxins are stored in your fat cells, and fasting helps you burn fat, which could also lower your toxicity levels.
For example, one study highlighted that fasting promotes autophagy and the natural process of removing harmful estrogenic compounds from the body. These estrogenic compounds negatively influence the overall hormonal composition of men and women. Detoxifying with methods like fasting can remove some of these compounds and normalize reproductive hormone levels. [8]
Improves Cholesterol
Men and women need optimal cholesterol levels to produce testosterone. One study followed participants on an alternate-day intermittent fasting regimen and concluded that they lost weight, improved blood pressure and had higher levels of HDL or “good” cholesterol. [9]
References
Cienfuegos, S., Corapi, S., Gabel, K., Ezpeleta, M., Kalam, F., Lin, S., Pavlou, V., & Varady, K. A. (2022). Effect of intermittent fasting on reproductive hormone levels in females and males: A review of human trials. Nutrients, DOI: 10.3390/nu14112343
Rojdmark, S., Asplund, A., & Rossner, S. (1989). Pituitary-testicular axis in obese men during short-term fasting. Acta Endocrinol (Copenh), DOI: 10.1530/acta.0.1210727
Habito, R. C., & Ball, M. J. (2001). Postprandial changes in sex hormones after meals of different composition. Metabolism, DOI: 10.1053/meta.2001.20973
Sutton, E. F., Beyl, R., Early, K. S., Cefalu, W. T., Ravussin, E., & Peterson, C. M. (2018). Early time-restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress even without weight loss in men with prediabetes. Cell Metabolism, https://doi.org/10.1016/j.cmet.2018.04.010
Yamauchi, T., Waki, J. K., Terauchi, Y., Kubota, N., Hara, K., Mori, Y…Kadowaki, T. (2001). The fat-derived hormone adiponectin reverses insulin resistance associated with both lipoatrophy and obesity. Nat Med, DOI: 10.1038/90984
The Cleveland Clinic. Leptin and Leptin Resistance. Retrieved on September 22nd 2023. Leptin: What It Is, Function & Levels (clevelandclinic.org)
Weigle, D. S., Duell, P. B., Connor, W. E., Steiner, R. A., Soules, M. R., & Kuijper, J. L. (1997). Effect of fasting, refeeding, and dietary fat restriction on plasma leptin levels. J Clin Endocrinol Metab, DOI: 10.1210/jcem.82.2.3757
Kim, I., & Lemasters, J. J. (2011). Mitochondrial degradation by autophagy (mitophagy) in GFP-LC3 transgenic hepatocytes during nutrient deprivation. Am J Physiol Cell Physiol, DOI: 10.1152/ajpcell.00056.2010
Varady, K. A., & Hellerstein, M. K. (2007). Alternate-day fasting and chronic disease prevention: A review of human and animal trials. American Journal of Clinical Nutrition, DOI: https://doi.org/10.1093/ajcn/86.1.7
