5 Ways Fasting Can Benefit Your Health

This is a guest post by Ben Tanner, who is writing on the topic of fasting.

For those of you who haven’t tried it, fasting is the new (but old) dietary hack that can really make a difference in your health. I’ve been doing it for a few years now, and it has helped with weight loss, but also delivered improvements in blood sugar balance and lower blood pressure! So I do think that it’s a technique that you can use to up your game when it comes to nutrition.

After all, nutrition is more than what you eat; it’s also what you don’t eat.

What follows is Ben’s article. Enjoy!


In the past few years, fasting has become pretty popular as a weight-loss tool.  

But a lot of people still aren’t sure if it’s beneficial for their overall health.  For example, I regularly see questions like, “Is fasting good for you?”, or, “Can women fast?”.  

On the one hand, it’s understandable that people would ask those questions, since we’ve been bombarded in recent years with the message that we need to eat constantly, or something terrible might happen.

(Turns out, that’s mostly the result of marketing by the food industry, and typically nothing terrible happens if you skip a meal.)  

On the other hand, questions like those above seem kind of silly, since humans have been fasting regularly for thousands of years. So it can’t be that bad for us, or we wouldn’t have survived as a species.  

Today I’ll share with you 5 science-based reasons why fasting is good for your health.  I think understanding a little bit about the physiology of fasting is motivating, because it shows you a clear benefit you can get when you put it in practice. 

Fasting Keeps Your Blood Sugar in Check (and Prevents Diabetes)

There are many, many people with excessively high blood sugar. Those are the people that have diabetes, or pre-diabetes.

Type 2 diabetes in particular is becoming extremely common, and I see it during just about every shift in the emergency room.

Sadly, diabetes leads to all sorts of ugly complications, like blindness, kidney failure, amputations, and heart attacks, to name a few.

There’s a pretty simple connection between fasting and controlling blood sugar:

When you fast, your blood sugar gradually comes down. And if you have abnormally high blood sugar to start with, your blood sugar will gradually come down into the normal range.

Therefore, by instituting some type of fasting (short, long, or a combination), you can lower your risk of getting diabetes, and help improve the signs and symptoms if you already have it. 

In my book, anything we can do to improve or prevent type 2 diabetes (and the associated complications) is a major win!

Fasting Keeps Insulin in Check

Perhaps you’ve heard about the hormone called insulin. Your pancreas secretes insulin whenever you eat carbohydrates, and it helps push those carbohydrates into your muscle cells and fat cells.

However, when we eat too many carbohydrates, too often, our pancreas has to pump out so much insulin that the body can’t handle it anymore. So it kind of stops responding to the insulin.

That’s called “insulin resistance”.

Insulin resistance is what you get before you get pre-diabetes, followed by type 2 diabetes.  So it’s the first step towards….bad things.  

Insulin resistance not only leads to diabetes, it also contributes to a variety of other health problems, including infertility, migraines, and others.

Fasting is a great way to help bring down excessively high insulin, and reverse insulin resistance. From what I’ve observed, it’s probably the quickest way to accomplish this!

Fasting Lowers Your Risk of Many Other Chronic Diseases

In the previous section, I mentioned a couple health problems that are associated with insulin resistance.

Turns out, there are many more than that!

Diabetes and insulin resistance cause or contribute to almost every other chronic illness, including high blood pressure, heart disease, cerebrovascular disease (like strokes), dementia (like Alzheimer’s), cancer, kidney failure, liver failure, and the list goes on.

Overall, the logic is pretty simple here. Anything you can do to lower your risk of diabetes or insulin resistance will also lower your risk of most other chronic medical conditions.

I’m always saddened when I see devastating medical conditions in the ER that likely could have been prevented, just by making some dietary changes and eating less frequently (i.e. fasting).

Kidney failure is a classic example.  People with kidney failure end up on dialysis, having to spend about 12-16 total hours every week at a dialysis center to get their life-saving treatments.  

Diabetes is the most common cause of kidney failure. And in many cases, diabetes can be prevented or reversed with fasting.

That’s why when I see stuff like that, it makes me want to preach from the rooftops that fasting can help!

With the right fasting regimen, you can typically reverse type 2 diabetes, as well as insulin resistance. And by doing so, you’ll dramatically improve your long-term health outlook!

Fasting Leads to “Cleaning” and “Renewal” in Your Body

Not only does fasting lower your risk of chronic illnesses, it also makes some other cool things happen in your body.

For example, when you fast for more than about 24 hours, your body starts doing something called “autophagy”.  Autophagy means you start scavenging inside your cells to look for damaged, worn out, or old proteins to break down and recycle.  So it’s like a type of “spring cleaning”, or taking out the trash.

Another cool thing that can happen when you fast is your immune system gets “reset”.  

If you fast for more than about 3 or 4 days, your body starts breaking down some of your white blood cells (the immune system), while also making more stem cells. When you break your fast, it uses those stem cells to rebuild the portion of your immune system that was broken down.

The really cool part?

Studies have shown that this breaking down and rebuilding of the immune system reduces symptoms of autoimmune conditions like multiple sclerosis, or Crohn’s disease.   

If you have any type of autoimmune condition, fasting may be able to help a lot!

And even if you don’t have an autoimmune condition, fasting most likely lowers your risk of developing such a condition later on.

Fasting Improves Your Brain Function

When you fast, your metabolism gradually starts shifting from relying primarily on glucose (blood sugar) to using mainly fatty acids and ketones for energy.

Turns out, ketones are good for your brain!  They stimulate a substance called BDNF, which causes your brain to do more growth and repair.

On a related note, when people have a traumatic brain injury, they tend to do better if they get ketones than if they just continue to rely on their blood sugar.  (It’s almost as if the brain forgets how to use glucose for a while, after an injury.)

Similarly, patients with dementia often have some improvement when they go into nutritional ketosis (i.e. eat a ketogenic diet), probably because in dementia the brain isn’t as good at using glucose anymore, either.  

Lastly, I’ve also noticed that whenever I fast for more than a day or so, I reach a state of mental clarity that’s beyond anything I feel when I’m not fasting.

Overall, it’s pretty clear that fasting is beneficial for the brain!

Final Thoughts 

How can fasting benefit your health? Let me count the ways. 🙂

High blood sugar and high insulin lead to pre-diabetes, and type 2 diabetes. And those are probably the most common, and most harmful health problems that exist in our society today!

Fasting can bring about quick improvement in blood sugar and insulin levels. And by doing so, it can reduce your risk of getting just about every other chronic disease.

If you haven’t already given fasting a try, I hope by understanding some of the specific health benefits you can get from fasting, you’ll be more motivated to do so.

And if you’re wondering how to get started, I’ve written a complete beginner’s guide to intermittent fasting.  On that same page, you can also download my Easy Fasting Guide, which has some of my best tips to help you get a smooth start. 🙂 

Disclaimer:  Depending on your health status, you may need medical supervision when you start fasting.  Consult your medical provider.