Fasting: Good, Bad, or Both?

Fasting, an extremely controversial topic.

At least nowadays it is.

Fasting is certainly not a new practice and has been part of culture since the dawn of time.

For many cultures fasting was religiously observed to commune with God (or their tribe's gods). Some cultures fasted out of necessity, simply because there wasn’t enough food to go around and so they rationed food by not eating.

Only recently has fasting been looked at through the lens of holistic health improvements, and part of that is because of how so much disease today is caused by diet.

With fasting there seems to be some confusion as to whether or not it’s beneficial or harmful.

There are questions behind the methodologies of fasting and whether or not there are right and wrong ways to do it.

Fasting isn’t complicated, really, but we’ve made it so.

Which is why I wanted to talk about fasting, again.

It’s a topic I believe deserves repeated coverage owing to the power of fasting to positively affect health as well as people’s confusion and fear around the topic.

What Is Fasting, Really?

Fasting would seem to be a simple concept. Still, we’ve made it complicated…or rather, there are so many different ways to fast and various benefits with the different applications that it has become its own science.

There’s also the study of a different kind of dietary practice known as “caloric restriction” that gets lumped in with the fasting data.

The difference between the two is worth noting, mainly since both have observed benefits, but your body responds to each differently.

When a person practices calorie restriction what they’re doing is eating fewer calories than their body requires to maintain homeostasis.

If you were to calorie restrict forever you’d starve to death.

Fasting on the other hand is the complete restriction of consuming any calories whatsoever. And this, by definition, is starving yourself.

Interestingly enough, you can blend the two. And this is done by various forms of “fasting.”

I know I’m getting into the weeds already, so let me pull up to 30,000 feet and talk about why fasting and/or caloric restriction are helpful in the first place.

By reducing caloric intake, or eliminating the consumption of any calories you can achieve several known benefits.

Some of the most profound are: 

1 - Real, Sustained Weight Loss: Fasting can help with weight loss by reducing calorie intake. A study published in the International Journal of Obesity found that fasting can lead to significant weight loss and improved insulin sensitivity.

What’s really cool is if fasting and caloric restriction are incorporated into a regimen or lifestyle, then weight loss can become permanent.

2 - Improved Brain Function: Fasting has been shown to improve brain function and increase productivity. A study published in the Journal of Neuroscience found that fasting can increase the production of brain-derived neurotrophic factor (BDNF), which is essential for learning and memory.

If you fast often enough and eat a diet that lets you switch to ketone production quickly (a fat-adapted diet) then the production of ketones will also allow for enhanced brain function. 

3 - Reduced Inflammation: Fasting has been shown to reduce inflammation in the body, which can lead to a reduced risk of chronic diseases such as heart disease and cancer. A study published in the Journal of Nutritional Biochemistry found that fasting can reduce inflammation and oxidative stress.

Part of that has to do with reducing the intake of inflammatory foods (at least for many Americans), and part has to do with autophagy (when your body eats itself which I wrote about here). 

4 - Improved Insulin Sensitivity:  This is far and away one of the top benefits of fasting, as insulin sensitivity (or insulin resistance for that matter) is directly tied to a long list of chronic health issues.

Fasting has been shown to improve insulin sensitivity, which can reduce the risk of developing type 2 diabetes. A study published in the Journal of Clinical Endocrinology and Metabolism found that fasting can improve insulin sensitivity and reduce insulin levels.

5 - Boosts HGH production: Human Growth Hormone (HGH), a hormone produced naturally by the body, plays an important role in various physiological processes. HGH secretion, however, remains active in the bloodstream for only a few minutes before it gets metabolized and eliminated from the body.

HGH is effective in combating obesity and promoting muscle mass, which is important for burning fat. One way to enhance the secretion of HGH is through fasting. Fasting has been shown to boost HGH levels, which in turn can help increase muscle strength. Improved muscle strength can lead to better workout performance, which can ultimately help in weight loss efforts.

By combining the effects of HGH secretion enhancement and increased muscle strength, one can effectively turn their body into a fat-burning machine. This makes HGH an enticing option for those looking to lose weight and build muscle mass.

And there’s more than just this.

But now let’s talk about the supposed dangers of fasting… after all, if you’re not eating and you’re starving yourself, you’ve got to be doing yourself harm, right?

The Dangers of Fasting

Here’s the deal, fasting is not inherently dangerous.

Yes, it can be if you have an underlying health condition that you and your doctor are aware of.

It can also be dangerous if you don’t take certain basic precautions (more on those in a second).

And it could be dangerous if you overdo it. Meaning you fast for too long, or too often and don’t realign around a healthy intake of food and nutrients.

Let’s talk about the most common things that can go wrong with fasting (and then you’ll see the obvious issues).

The first thing is you could suffer from dehydration, especially during prolonged periods. This can cause symptoms such as dizziness, headaches, and fatigue. It can also lead to electrolyte imbalances, which can cause muscle weakness, cramps, and irregular heartbeat.

The easy fix is to drink all day long and consume electrolytes if you’re going for several days without eating.

Another potential danger of fasting is malnutrition. When someone fasts, they may not be consuming enough nutrients, which can lead to deficiencies in vitamins and minerals. This can result in a weakened immune system, anemia, and other health problems.

Now, this is something I don’t think many people need to worry about. Especially if you’re overweight and are using fasting to bring your BMI under control.

Should your fast be extended you can always take multivitamins to help round out nutrition. 

Lastly, fasting can also be dangerous for people with certain medical conditions. For example, people with diabetes can experience dangerously low blood sugar levels while fasting, and those with eating disorders may develop unhealthy behaviors or trigger relapses.

Though going a day, 3 days, or even 7 days without food isn’t necessarily dangerous, even though fasting and caloric restriction can feel awful.

Feeling bad while fasting (especially the first day or two of an extended fast), is a physiologically good thing as your body is sending signals to your brain that it’s stressed out and fighting to stay alive… but that response is actually good for your health.