Intermittent fasting has gained a lot of hype and publicity over the past few years. This has been fueled by the ancestral and paleo movements that have brought this historic technique back into mainstream. The origins of intermittent fasting date back to the original humans on Earth who were constantly going in and out of fasting physiological states in their bodies. This was a survival mechanism that their bodies utilized, as food sources were not as consistent or plentiful and convenient as they are today. As their glycogen (sugar) stores were depleted, they would begin to switch fuel sources and use fat for energy. This remarkable biological adaptation has allowed humans to survive for thousands and thousands of years.
Fast forward to today, where humans are not hunter-gatherers any longer and have abundant sources of foods at our disposal. We no longer need this adaptation to survive, but we most certainly can use it to advance our health. The science of this ancient adaptation has now revealed what our ancestors knew centuries ago. Let’s dive into the top 5 benefits of intermittent fasting.
Fasting has a very strong impact on our bodies’ hormones and in fact increases some of the good hormones and decreases some of the bad hormones. We now know that fasting dramatically increases the human growth hormone in our bodies. This hormone helps increase lean body mass, increase muscle strength, and decrease fat (adipose) tissue in our bodies. Insulin, which is secondarily responsible for fat storage, significantly decreases during a fast. This enables people to burn fat as their fuel source instead of sugar (glucose, glycogen).
This is probably the most well known and sought after benefit of intermittent fasting. After 16-18 hours of not eating, our bodies burn through all of our saved sugar (glycogen) stores. This forces the body to switch fuel sources to keep running. As a result, insulin levels go very low because there simply is no sugar in the body’s bloodstream. This stops fat storage and starts fat burning. It also increases norepinephrine, which increases our resting metabolic rate. Basically, our bodies are running at a higher RPM and burning up fuel (fat) at a quicker rate. Researchers have also found that after the fast has been completed, people tend to eat less on the following unrestricted days. This adds additional weight loss and increases the effects of the fast beyond the physiological fasting state in the body.
This benefit is great for athletes who are experiencing inflammation from training and competition as well as for the general public who may have inflammation from a poor diet and increased intestinal permeability. Fasting helps reduce certain cytokines, which are inflammatory signaling proteins that can cause pain in the body. Fasting also reduces inflammatory C-Reactive Protein (CRP), homocysteine, and oxidative stress in the body. The suppression of various inflammatory markers and molecules has profound benefits, as we know inflammatory pathways are involved in many chronic diseases such as diabetes and cardiovascular disease.
Intermittent fasting has been shown to optimize the brain’s functionality by improving its metabolism of glucose, which is inflammatory and can cause oxidative stress. Fasting also has a neuroprotective effect by lowering cytokines in the brain and protecting neurons from ischemic (poor blood flow) injuries. It also increases brain-derived neurotrophic factor (BDNF), which specifically protects neurons from degeneration. Not only is BDNF protective, but it also helps neural stem cells replicate and grow in the brain. This allows regeneration of nerve tissue in the brain to take place, which is called neurogenesis.
The benefit of longevity due to calorie restriction has been well recognized for some time in the research community with various animal model examples demonstrating this effect. As the anti-aging movements have gained popularity, fasting has now become in vogue once more. By restricting calories through a fast, the body goes through many different physiological changes. These include increased growth hormone, decreased insulin, increased insulin sensitivity, increased gastrointestinal stem cells, increased neural stem cells, decreased oxidative stress, and lower inflammation, which all contribute to increased lifespan. These benefits have been well documented, and they make sense when you think about it. By training the body to move into and out of different adaptive states, we are able to positively impact our physiology, hormones, and metabolism. This essentially makes us more efficient.
Intermittent fasting is a powerful and effective strategy that benefits the body in a number of positive ways. I have been using it in my Gilbert, AZ clinic over the past year with my patients and have noticed good results. The best part of intermittent fasting is that it is 100% free and relatively easy to do. I usually advise people to try it 1-2 times per week to start out with and then increase duration or length if they are tolerating it well. This technique is not for everyone of course, and a medical professional should be consulted beforehand and during to monitor for any adverse reactions. When applied correctly, this is by far the most cost effective medical treatment for the human body. Humans have utilized this for hundreds of thousands of years and its adaptive mechanisms have helped us survive as hunter-gatherers to modern day warriors. For more information about fasting, our Naturopathic Medical Doctors, or Atlas Health Medical Group’s Gilbert, AZ clinic, please call 480-648-1534.