Why You Should Be Fasting

Fasting has numerous benefits on your health, and it's safe for most people.

Being a dad, I often attend daylong school and sports events with my kids. I usually pack snacks and lunch for them. 

Recently, while I was packing a basket with food and water, it hit me that I never pack any food for myself. I don’t order food either when I am at these events. I simply go the entire day without eating. And this is with a light or no breakfast. 

I don’t feel hungry at all or think about food. Even by dinner time, I am not keeling over with hunger. 

I hadn’t realized until then how much my relationship with food had changed in the last two years. Before, I thought about food probably a dozen times an hour, whether I was hungry or not. I also used to feel an extreme dizzying hunger if I went just a few hours without eating.

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Two things changed my relationship with eating: going on a low carb diet (lazy Keto) and starting regular fasting. 

It was hard at first, but it’s surprising how quickly your body can adapt. Within a few months, the thought of eating breakfast made me nauseous. Before, I couldn’t wait to wake up to eat.

Now, even when I am not purposefully fasting, I can easily go 12 hours or more without food and it’s no big deal. 

Why You Should Be Fasting

There is still a lot we don’t know about the effects and benefits of fasting. But current research has uncovered enough benefits and shown it to be safe enough for most people that I can confidently recommend that most people should be fasting regularly. 

There are minor side effects that affect some people such as headaches and fatigue. Fasting can also be dangerous if you don’t do it right (e.g. you start fasting for 12+ hours right away or you if you don’t hydrate adequately). There are also people for whom fasting is not recommended like pregnant moms, the elderly and people with certain health conditions. 

But for most people, the benefits of fasting are so powerful that it’s surprising that fasting is still not accepted widely in public health and medical circles. 

Types of Fasting

When I talk about fasting, I am mostly referring to intermittent fasting or IF, the most popular type of fasting. The most common variation of IF is 16:8, where you fast for 16 hours and eat within an 8 hour window.

You can choose your own variation depending on how long you’ve been fasting. I advice most people to start with an equal 12:12 ratio. Eat your breakfast 12 hours after you ate dinner. That’s super easy since you’ll be asleep most of that time. 

You can then slowly ramp up your fasting window pushing your breakfast later every few days and eventually getting to a point where you can skip it. Or you can eat your dinner earlier if you have to have breakfast. 

The most experienced fasters can easily do a 20:4 style of intermittent fasting, eating all their meals in a four hour window. 

In addition to intermittent fasting, there are longer types of fasts that have even bigger health benefits. These range from 24 to 72 hours. 

Once you are comfortable doing intermittent fasting daily (or most days) you can try an extended fast once a week or every two weeks.

5 Proven Health Benefits of Fasting

When you stop eating and digestion quiets down after several hours, a lot of stuff begins to happen in your body. These physiological changes during fasting deliver a multitude of health benefits. 

I am going to talk about the five biggest ones.

1. Fasting Lowers Blood Sugar 

Intermittent fasting is one of the most effective ways to manage blood sugar levels in diabetics and pre-diabetics. In one study published in the Journal of Clinical Endocrinology & Metabolism, 36 people with diabetes were put on a 3-month intermittent fasting diet. 

90% of the participants experienced enough improvements in their blood glucose and insulin resistance that they reduced their medication. 55% went into remission and discontinued their medication. 

So not only does fasting reduce blood sugar, it has been shown to reverse diabetes. 

When you fast, your body is not getting constantly bombarded by glucose (this constant bombardment is one of the reasons why insulin resistance develops). 

This causes blood sugar to fall. Insulin levels drop too. 

With less insulin being produced, your cells become more sensitive or less resistant to insulin. So when you take your next meal, they absorb more sugar from the blood, which helps control blood sugar levels. 

Keep up with fasting long enough and your body is able to control blood glucose on its own without requiring medication. 

Even if you are not diabetic, you should still fast to keep your blood sugar at healthy levels. It reduces your risk of becoming diabetic. 

Safety tip: If you have diabetes, be careful with fasting. Blood sugar can get dangerously low, especially if you are also taking diabetes medication. Talk to your doctor before you start fasting and keep monitoring your blood sugar levels. 

2. Fasting Triggers Autophagy 

Autophagy is the body’s natural cell recycling and rejuvenation process. It is one of the biggest reasons to start fasting. 

When your body is deprived of nutrients — such as when you fast — it first uses stored glycogen for energy. That gets depleted pretty fast. 

Next, it turns proteins into glucose for energy, a process called gluconeogenesis. These proteins come from old and damaged cell parts. The recycling of these old, damaged and non-functional cell parts is what we call autophagy.

These parts are used to produce energy and make new cells. 

By cleaning up old and damaged cell parts, fasting reduces inflammation, eliminates toxic substances and protects cells from damage. 

Autophagy lowers the risk of various diseases including Alzheimer’s, heart disease, diabetes, liver disease, cancer, autoimmune disorders and others. It’s also possible that autophagy lengthens lifespan. 

Note that autophagy kicks in after about 18-24 hours of fasting. So a regular 16:8 intermittent fasting regimen is not enough to fully trigger autophagy. That’s why you should have longer 24-48 hour fasts every one or two weeks. 

3. Fasting Reduces Inflammation

Inflammation is the excessive and prolonged reaction of the body’s immune system to a perceived threat. It can cause or worsen many health problems including diabetes, heart disease, dementia, arthritis, asthma and more. 

Fasting tackles inflammation by reducing the amount of monocytes circulating in the blood. Monocytes are a type of immune cells involved in inflammation. 

That said, research is still unclear on the effect of prolonged fasting on the immune system. One study in mice found that refeeding after a 24 hour fast caused monocytes to surge back into the blood, resulting in higher inflammation. 

But that was just one study and it was in mice. So far, most research points to fasting having a net positive effect on health. Intermittent fasting, where you fast for part of the day, improves chronic inflammatory disorders. 

4. Fasting Helps You Lose Weight 

When done consistently and safely, fasting is an effective way to lose weight and maintain a healthy weight. 

The most important thing is to start slowly and think long term. Fasting for too long too soon is not only unsafe, it leads to the yo-yo effect where you lose weight only for it to come back. 

You need to think of fasting as a lifelong lifestyle change. To do this, you’ll need to sustain it. To sustain it, you’ll need to start slowly and ramp up gradually. 

I recently wrote a brief guide on how to start and sustain fasting.

Over the long term, fasting helps you lose weight in three ways:

• By calorie restriction — even without tracking calories, most people automatically eat less when they do intermittent fasting. 

• Via fat metabolism — fasting forces the body to turn to fat to meet its energy demands. After around 12 hours of fasting, your body begins to burn fat. This not only helps you shed pounds, it also reduces the amount of harmful visceral fat in your body. 

• By lowering blood sugar and insulin resistance — too much insulin in the blood causes the body to store excess glucose as fat, causing weight gain. Fasting reduces insulin resistance, resulting in lower insulin levels.

5. Fasting Helps You Live Longer

The link between fasting and lifespan is still under research. But a number of studies indicate that fasting could potentially help us live longer. 

This is not because of a single process or benefit; rather, it’s a combination of the many benefits of fasting. 

For example, fasting reduces your risk of heart disease, diabetes and other diseases. Without these health problems, you are more likely to live longer. 

Autophagy may also increase longevity by reducing cellular damage. Damage to cells is one of the proposed causes of aging. 

Fasting may also change our DNA in ways to allow us to live longer. 

Fasting doesn’t just increase longevity; it also increases our healthspan. This is how long we live in good health. Fasting regularly helps you stay healthy and energetic as you age. 

Summary

For a long time now, researchers have known that caloric restriction (eating less) has major and lasting benefits on human health. 

Fasting, and particularly intermittent fasting, is one of the best and safest ways to practice calorie restriction. 

Other potential benefits of fasting that are under research include lower blood pressure (important for heart health), better mental health (most people report experiencing better moods and mental clarity) and reduced risk of cognitive disorders like Alzheimer’s.

Personally, the biggest impact fasting had on me was changing my relationship with food. From feeling hungry almost constantly, to easily going the entire day without thinking about food has been a life-changing shift. 

I don’t overeat and I don’t crave unhealthy foods as much as I used to. This shift did not happen overnight. The first few weeks of fasting had me craving sugary foods and I often had cheat days when I wouldn’t fast. More than a few times, I broke my fast because of how hungry I would get. 

But it got easier with time. Start slowly and be gentle on yourself. This is a long term game, after all. 

Cheers and all the best in your health.