Food is the energy we put inside our body to help it power its processes, build muscle and carry out essential repairs. To suggest that taking this away is a good thing seems counter-intuitive, yet this is exactly what scientific studies tell us need to happen. To understand why and why we benefit, we must also examine, to some extent, the role of food.

The food we eat provides nutrients for us which are used to carry out a variety of functions in our body. Everything food does however comes down to a very simple, fundamental process: the production of Adenosine Triphosphate (ATP) ^[1] which powers our body at a cellular level. Viewed like this, food becomes free of its type-casting into particular dietary labels and it then becomes a regulatory mechanism ^[2] for energy consumption in the human body. In plain English, regulating the amount of food we eat also regulates the amount of energy the body has to put into things like work, exercise and inflammation.

Regulate Your Energy, Lengthen Your Lifespan

Long-term, meticulous studies of different types of hunter-gatherer societies have shown that despite having varied types of diet they all exhibit great health, have very low incidence of type 2 diabetes, obesity and metabolic diseases such as increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels. These, so-called “civilization diseases”^[3], typically occur together, and increase our risk of heart disease, stroke and diabetes.

What is common across different types of hunter-gatherer communities is their very active, daily lifestyle. Physical activity is an energy regulation system that is closely linked to food. The suggestion is that when the two are combined in such a physically active setting the body reaches an equilibrium where appetite is regulated to match energy needs and the energy needs of the body are restricted to the physical activities performed, building and repair with very little energy to spare.

The idea that excess energy may be the culprit behind illnesses and conditions that shorten our lifespan by undermining our health is one that has been explored quite extensively in tests and animal studies ^[4]. These have shown consistently how calorie restriction in the diet achieved either through fasting or intermittent fasting helps extend their lifespan beyond average. Calorie restriction has been shown to improve biomarkers of disease, reduce oxidative stress in the body and preserve learning and memory functioning^[5].

One mechanism through which such health benefits are achieved is the regulation of energy which places cells under stress and triggers an adaptive response. Researchers say that “There is considerable similarity between how cells respond to the stress of exercise and how cells respond to intermittent fasting,” and the result of either [or both] is that the body then adapts and grows stronger as it recovers from the effects of intermittent fasting or exercise.

The idea that excess energy due to food over-consumption or lack of physical activity aids in the growth of tumors is backed by research that shows test subjects who suffered from cancer and received chemotherapy reduced the size of their tumors and also protected themselves from the side-effects of chemotherapy through fasting^[6]. The reduction in energy made available to the body through fasting reduced the amount of energy tumors could draw upon to grow and also reduced the amount of energy the body had to put into the inflammatory (and damaging from a cardiovascular point of view) response.

Physical, Mental and Cardiovascular Benefits of Intermittent Fasting

Because intermittent fasting isn’t specific to any particular type of diet it is more a lifestyle choice than a dietary exercise. Any length of time between 8 and 48 hours without food is considered a fasting interval. Obviously there is no snacking of any sort taking place and, during the fasting interval any beverage such as coffee or tea that has more than 50 Calories is considered to have broken the fast because it stops the body from using up its fat stores and carrying out essential maintenance and repair at a cellular level^[7].

The benefits of intermittent fasting do not stop there however. While far from exhaustive and while there’s still research being carried out to further understand the metabolic pathways through which fasting helps the body this list of physical, mental and neurological benefits show exactly why intermittent fasting should be on everyone’s list of things to do from time to time:

• Glycogen depletion and insulin resistance recalibration through exercise while fasting^[8].
• Improved metabolism, gut microbiota and circadian biology^{[9, 10]}.
• Improved cardiovascular health and improved blood circulation in the brain^[11].
• Weight control^[12].
• Can improve the brain’s chances against Alzheimer’s^[13].
• Reduced chances of heart disease^[14].
• Reduced inflammatory response in the body and improved immune system^[15].
• Increased lifespan^[16].
• Improved memory, cognition and mood ^{[17, 18]}.
• Promotes neurogenesis and reduces chances of Parkinson’s^[19].

Whichever way you approach it, right now, regulating the energy available to the body through intermittent fasting is a lifehack that delivers science-backed health benefits.