How Does Fasting Maintain Testosterone Levels?
People who fast a lot worry about dropping muscle, or even testosterone levels, affecting their ability to do either. Testosterone is so important for men. Because this has to do with our ‘ability’, what we want of course is to be stronger, more capable, more in control.
Testosterone is the main male sex hormone, affecting libido, but also has a very important role in bones, muscles, mind, mood and even obesity, diabetes and cardiovascularity.
Maintaining adequate levels of testosterone is essential for men’s health as well as staying energized.
The good news is that it is surprisingly possible to increase testosterone levels by fasting, take a look and see, how it works.
Fasting, Re-Eating, Stronger and Firmer
Back in 1913, Dr. Sergius Morgulis took a keen interest in this phenomenon when he discovered that temporarily starving an animal seemed to allow it to grow rapidly upon refeeding.
In his paper, “Effects of Prolonged and Intermittent Fasting on Growth,” he cites a study that says chickens that were deprived of food and then refed grew heavier, stronger, and firmer, but specifically points out that the weight gain didn’t come from fat-a century-old study.
Sergius Morgulis was born in Russia on August 6, 1885, and in 1910, he earned a PhD in biology from Harvard University.
Morgulis later became an assistant at the Carnegie Institution on Nutrition Labs. From 1913 to 1916, Morgulis was an associate professor of biochemistry at Columbia University’s College of Physicians and Surgeons.
He served as professor of biochemistry and physiology at Creighton University School of Medicine from 1916 until 1921, when he was appointed professor of biochemistry at the University of Nebraska College of Medicine.
Biologist Walter Longo explained that fasting and refeeding is a process of breakdown and rebuilding. He calls fasting ‘auto-repair mode’.
A paper published by Longo in 2021 discusses intermittent fasting and periodic fasting as having the potential to prevent and treat disease, and highlights the benefits of fasting and refeeding.
Fasting creates conditions for your body to recover stronger when you reintroduce food.
In 2018, Walter Longo explained on his podcast with Rhonda Patrick that there is a growth factor called IGF-1 that helps muscle and brain cells grow.
Longo explains that when you temporarily reduce this growth factor by fasting, stem cells are activated.
And when you restore IGF-1 by supplementing with protein, these activated stem cells replicate and multiply themselves, which stimulates the growth of all types of cells.
Eating after fasting increases testosterone levels in men
How does fasting affect testosterone?
Here’s what researchers did; they administered GnRH before fasting and after 56 hours of fasting found that the longer the fast, the more sensitive the body was to GnRH.
It raised more luteinizing hormone (FSH) and also more testosterone.
What are GnRH and FSH? How does the HPG axis associated with both work?
→ Fasting regulates testosterone levels through the function of the hypothalamic HPG axis
The hypothalamic-pituitary-gonadal axis (HPG axis) is the centerpiece of the neuroendocrine system, which precisely regulates male reproductive function through a series of complex hormonal feedback mechanisms.
This hormone produced in the brain is known as gonadotropin-releasing hormone (GnRH), which is key to testosterone production and initiating puberty.
The hypothalamus produces GnRH, which is the initiating signal for the HPG axis, and it is periodically released into the bloodstream, which in turn affects the activity of the pituitary gland.
The pituitary gland, a small gland located at the base of the brain, receives the GnRH signal, which stimulates the pituitary to secrete gonadotropins (LH) and luteinizing hormone (FSH).
The male gonads are the testes, which respond to FSH and LH to produce sex hormones such as testosterone and to promote sperm production.
Specifically: LH helps convert cholesterol into testosterone in testicular interstitial cells (leydig cells), and FSH binds to cholesterol, ultimately forming sperm cells.
Sexual function includes not only reproductive capacity, but also psychological and physiological responses such as libido, sexual arousal, and orgasm.GnRH and LH are also involved in the regulation of sexual behavior and sexual arousal, and they act indirectly by influencing the secretion of testosterone.
→ What factors affect the function of the HPG axis?
1. age. As we age, the production of GnRH decreases, which may lead to a decrease in sex hormone levels.
2. stress and emotions. Chronic stress, insomnia and negative emotions can affect the nervous system, which in turn affects the secretion of GnRH and the sex hormones.
3. Lifestyle. Poor diet, lack of exercise and late nights can negatively affect the function of the HPG axis.
4. Diseases and medications. Certain diseases and medications may interfere with the normal function of the HPG axis.
Fasting seems to allow some people’s bodies to increase testosterone production when they eat again.
→ Eat protein after fasting to increase IGF-1 levels
Walter Longo has said that eating protein after fasting increases the growth factor IGF-1.
A paper published in the journal neuroendocrinology in 2021 describes how IGF-1 plays an important role in the onset of puberty because it induces the release of GnRH.
It is important to be clear that IGF-1 does not exactly raise testosterone after fasting, and there are other ways that fasting can raise testosterone in some people.
For example, improving insulin sensitivity, improving mitochondrial function, or lowering triglycerides.
A 1991 study in rhesus monkeys found that the more the monkeys ate after fasting, the greater the luteinizing hormone (FSH) and the higher the testosterone in their testosterone.
In fact, they found that luteinizing hormone (FSH) was much higher on refeeding days after fasting compared to normal feeding days.
Therefore, stressing the body by fasting and giving the body nutrients to recover brings many benefits to the cells, and subjecting the organism to mild stress can rejuvenate the body and grow new mitochondria or brain cells.
Eating after fasting and how to eat
In Upton Sinclair’s old book on fasting he tells of a man who ate half a dozen figs during a 50-day fast , which resulted in an abrasion of the intestines and a lot of blood.
Upton Sinclair also mentions that people have mild bile attacks when they eat overfattened beef, but they recover quickly when they eat lean beef.
Therefore, in order to get the growth benefits, you need to consume protein after fasting.
In this way, your body will be able to increase its growth factors, resulting in what Walter Longo calls “body rejuvenation.”
You need to strike a balance between fasting and refeeding and nourishing your body. Dr. Mark Mattson explains that both fasting and refeeding are necessary to get all the health benefits.
So what should we eat after fasting and refeeding to maximize the benefits to our bodies?
→ Eat a light protein
When we are fasting, our bodies are in an insulin-sensitive condition (the body is ready to absorb all the food you are going to eat in).
When we are eating high carbs + fats, the body is the first to go and elevate insulin, which is then stored in the body.
So, for your first meal after fasting, it’s best to start with a little light protein. Then go back to enjoying a normal meal. Eat slowly, don’t rush, listen to your body’s feedback, and don’t overeat.
You can add a little cinnamon to lower insulin secretion; you can also drink a little apple cider vinegar to stimulate enzymes and aid digestion.
→ Eat foods rich in good quality fats
Good quality fats are important for testosterone production. Cholesterol is a precursor to testosterone and is essential for testosterone production.
Natural foods rich in good quality fats and cholesterol are all rich in a variety of other important nutrients at the same time, which, are very beneficial for testosterone synthesis and overall health.
→ Eat slowly and don’t eat too much at first.
Eat less at first and allow your body to gradually recover from the fasting state slowly, then you can eat normally.
Good quality fats are very important for men, and foods rich in oils and fats can make us feel more powerful and full of energy.
→ Replenish electrolytes
During fasting it is important to replenish electrolytes, which are minerals that the body carries electrons in, such as sodium, potassium, and magnesium, and are found mainly in ionic form in our blood, urine, tissues, and other bodily fluids, and are responsible for maintaining the normal functioning of many bodily functions.
During a normal diet, glycogen binds water in the body, with 1 gram of glycogen carrying an average of about 3 grams of water. Each person has about 550 grams of glycogen in their body. As the fasting period increases, the glycogen stored in the body is slowly depleted and the water flows out of the body with the body fluids.
During fasting, the body becomes heavily dehydrated and loses electrolytes. Electrolyte deficiencies can make the body uncomfortable, easily fatigued and hungry.
For example, potassium deficiency will cause muscle weakness, cardiac arrhythmia, renal dysfunction and hypertension; magnesium deficiency will cause cramps, hyperreflexia, hallucinations, confusion and other physical reactions. Therefore, timely replenishment of electrolytes can relieve discomfort.