This Is How Fasting Extends Your Life

Regular eating disrupts a critical process that keeps you alive.

Younes Henni, PhD
4 min readAug 31, 2021
Photo by Engin Akyurt on Unsplash.

Fasting has seen an explosion of scientific research in recent years. And the evidence has reached a solid conclusion: Eating whenever you feel hungry — snacking now and then — shortens your lifespan.

Our bodies are built for periods of hunger. The Romans ate once a day, and our hunter-gatherer ancestors went for days without food. In fact, the “three meals per day” protocol is relatively recent in our history: starting in the nineteenth century with the industrial revolution.

Every time you eat, your body produces insulin. If you eat often, your pancreas keeps releasing insulin into your body even while you sleep (digestion takes 7 to 12 hours to complete). When your insulin levels are always high, you disrupt a process known as autophagy.

Autophagy is the process by which your body gets rid of its waste. Think of your body as a neighbourhood and autophagy as a waste disposal company. Without disposing of waste, the whole community will drown in filth. The same principle applies to the body. Without autophagy, you won’t get rid of your toxic waste: it is one of the body’s most vital processes.

The heroes behind autophagy are called lysosomes. These cells locate the body waste, break it down into amino acids (the building blocks of DNA, RNA, and protein), then use these building blocks to make new cells or provide energy to the organs. Under this process, you’ll reap many health benefits:

  • You reduce the risks of cancer. That’s because autophagy prevents toxins from accumulating in damaged cells and infected cells from gathering.
  • You’re more protected against mental health problems. Autophagy helps recycle damaged brain cells to make new neurons and strengthen existing ones.
  • Autophagy also disrupts the accumulation of prions, an abnormal protein that causes neurodegenerative diseases, such as Alzheimer’s, Parkinson’s, Huntington’s disease, and epilepsy.
  • And because it regenerates old cells, autophagy helps you live longer.

If you snack every couple of hours, you’re not allowing autophagy to run its entire course. As a result, toxic waste keeps accumulating in your cells. When this happens, your immune system weakens, your sleep is disrupted, and your cognitive skills (memory and focus) deteriorate. Needless to say, your risk of diabetes, cancer, high blood pressure, and neurodegenerative diseases skyrocket.

Autophagy begins when glucose and insulin levels drop considerably and when your body digests all you’ve eaten. That’s why a minimum fasting time of 14 to 16 hours is key. Only then does your body start making energy from all the waste available in various organs such as the stomach, liver, intestines, kidneys, and lungs.

There are several ways to start a fasting habit. The easiest way (and beginner friendly) is to skip meals. If you’re used to eating three meals a day, maybe you can skip lunch and only eat breakfast and dinner.

Another beginner-friendly technique is the caloric crash. Eat regularly one day and limit your food intake the day after. For example, if your food intake is 2000 kcal on a typical day, reduce it to 500 kcal on the next day.

Once you get into a habit of skipping meals, you can move to a more rigorous fast to promote autophagy.

One of these best ways to practice intermittent fasting is the 16/8 system. For example, you eat between noon and at 8 PM, then fast until the next day at noon. Repeat. A similar method is the 14/10 system. An example would be to eat from 8 AM to 6 PM, then fast until the next day at 8 AM. Repeat.

Seasoned faster will opt for a 24-hour fast once a week. For instance, they will eat at 7 AM, then fast until 7 AM the next day. Though not suitable for beginners, it’s within a 24-hour fast that the process of autophagy is likely to reach its peak.

See what method suits you best. The key is to start slow and stay consistent. Some people do the 16 or the 14 hours fast as close to bedtime as possible. Since sleeping most of those hours makes fasting less challenging. You can even download some great tools (such as mobile apps) to help you practice the fasting technique you’re most comfortable with.

Whatever you decide on, consult your doctor before starting a fasting habit. Also, make sure to break your fast with nutrient-rich food: vegetables, fruits, quality protein (lean meat, fish), and healthy fats. This way, your body will recharge with all the nutrients it needs.

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Younes Henni, PhD

Physicist • Soft Dev • ☕ Junkie • I bring you the latest in science, tech, health, economics & personal growth. To read all: