This article is shared with permission from our friends at Fit and Healthy Beyond 50.

In my detailed guide on how to start a low carb diet correctly, I mentioned that one way to augment your low carb high fat or LCHF Diet is through intermittent fasting especially if you’re traveling and access to low carb foods may be limited.

In this article, I’m going to give your 6 great reasons why intermittent fasting is good for you and how you can incorporate it into your LCHF lifestyle. I call it a lifestyle and not a diet because that’s what it is; an extremely healthy lifestyle where you can prevent almost all the chronic illnesses, and if you are afflicted with one, you can slowly take steps to control and even reverse your condition.

But before we go into the 6 reasons let’s look at what the critics say – that fasting is not good for you because you’re depriving your body of nourishment, and if you fast too long, your body will go into a starvation mode because it’s catabolic and you’ll lose lean muscle mass.

Humans Fasted and Feasted in Prehistoric Times

Before the transition to the agricultural revolution, prehistoric humans fasted and feasted – that was how our ancestors lived. The food wasn’t readily available to our hunter-gatherer ancestors, and they didn’t yet have the know-how on crop planting.

Fasting and feasting were the way of life then – when they managed to hunt down small animals and gathered fruits, tubers and vegetables for food, they feasted. When food was scarce, they fasted – and they were nomads, going to where the food sources were.

So as you can see, fasting was a way of life back then. Prehistoric humans certainly didn’t have any adverse effects from fasting otherwise humankind wouldn’t have survived till now.

Fasting Vs. Starvation

Critics say that fasting puts the body into a starvation mode; this is simply not true. The difference is that with starvation, you don’t have any control as to when your next meal is coming. With fasting, you are totally in control, and you can break the fast and eat when you decide to do so. Also, when the body is in a true starvation mode, it slows down metabolism and holds onto fat stores.

According to Dr. Jason Fung, who has successfully treated thousands of obese and Type 2 diabetic patients using both LCHF and fasting,

“Starvation mode is guaranteed if you just try and cut your calories. But what’s interesting is that fasting doesn’t do that. What happens during fasting is that after four days of fasting, the basal metabolic rate is actually 10 percent higher than when you started.

The body has not shut down at all. In fact, what it’s done is it switched fuel sources. It changed from burning food to burning [body] fat. Once it’s burning [body] fat, it’s like, ‘Hey, there’s plenty of this stuff. Let’s burn our 2,000 calories’…”

Does Fasting lead to Muscle Loss?


According to Dr. Fung, this is another myth.

“If you follow the biochemistry, your body stores energy as glycogen in the liver, which is links or chains of sugar, and then it stores [it as] body fat.

During fasting, you start by burning off all the glycogen in the liver, which is all the sugar. There’s a point there where some of the excess amino acids in your body need to get burnt as well.

That’s where people say, ‘That’s where you’re burning muscle.’ That’s not actually what happens. The body never upregulates its protein catabolism. Never is it burning muscle; there’s an average turnover that goes on.

There is a certain amount of protein that you need for a normal turnover. When you start fasting, that starts to go down and then fat oxidation goes way up. In essence, what you’ve done is you switched over from burning sugar to burning fat. Once you start burning fat, there’s almost an unlimited amount of calories there. You could go for days and days.

What’s interesting is that if you take a pound of fat, that’s roughly 3,500 calories. If you eat somewhere around 1,800 to 2,000 calories a day, it takes two full days of fasting to burn a single pound of fat, which is very surprising to people. If you’re trying to lose 100 lbs, you could theoretically go 200 days of fasting just to burn all that fat.

People worry about fasting for 24 hours. I’m like, ‘You could go 200 days.’ Then it’s like, ‘OK. Maybe it’s OK to go 24 hours without eating.’”

6 Benefits of Fasting

Okay, now that we’ve dispelled the 2 most popular myths about fasting, let’s take a look at how your health can benefit from regular fasting.

Reason 1: Fasting Induces Autophagy and Increases Growth Hormone Release

According to New Medical, Autophagy is a normal physiological process in the body that deals with the destruction of cells in the body.

The term comes from Greek: auto is loosely translated as self, and phagein, to eat. So essentially, your cells create membranes that go out and hunt for diseased, dead and worn out cells. In other words, your cells are repairing and regenerating themselves.

Fasting promotes autophagy. According to Dr. Fung,

“Nutrient deprivation is the key activator of autophagy. Remember that glucagon is kind of the opposite hormone to insulin. It’s like the game we played as kids – ‘opposite day.’ If insulin goes up, glucagon goes down. If insulin goes down, glucagon increases. As we eat, insulin goes up, and glucagon goes down.

When we don’t eat (fast) insulin goes down, and glucagon goes up. This increase in glucagon stimulates the process of autophagy. In fact, fasting (raises glucagon) provides the greatest known boost to autophagy.”

“Fasting is far more beneficial than just stimulating autophagy. It does two good things. By stimulating autophagy, we are clearing out all our old, junky proteins and cellular parts. At the same time, fasting also stimulates growth hormone, which tells our body to start producing some new snazzy parts for the body. We are giving our bodies the complete renovation.”

What Dr. Fung says is supported by other independent studies on fasting such as this and this. In fact, the growth hormone release can be as high as 5 times during fasting.

Also with the inducement of autophagy, it seems that it can be protective against chronic diseases such as Alzheimer’s disease and cancer.

Reason 2: Fasting Reduces Blood Sugar, Insulin Resistance & Controls Diabetes

Fasting has shown to impact folks with Type 2 diabetes positively.

It has proved to reduce blood glucose levels by 3% to 6% and insulin resistance by 20% to 31%. So clearly, fasting regularly can certainly help control your blood sugar and reduce insulin resistance if you have the condition.

On the other hand, even if you don’t have full-fledged Type 2 diabetes, incorporating intermittent fasting into your lifestyle will definitely lower your risk of getting it as this study reported in Medical News Today shows:

Benjamin Horne, Ph.D., director of cardiovascular and genetic epidemiology at the Intermountain Medical Center Heart Institute and lead researcher on the study said,

“Together with our prior studies that showed decades of routine fasting was associated with a lower risk of diabetes and coronary artery disease, this led us to think that fasting is most impactful for reducing the risk of diabetes and related metabolic problems.”

Dr. Jason Fung echoes this view,

“Fasting is the simplest and fastest method to force your body to burn sugar for energy. Glucose in the blood is the most easily accessible source of energy for the body. Fasting is merely the flip side of eating – if you are not eating you are fasting. When you eat, your body stores food energy. When you fast, your body burns food energy. If you simply lengthen out your periods of fasting, you can burn off the stored sugar.

Since type 2 diabetes is merely excessive glucose in the body, burning it off will reverse the disease. If you don’t eat, will your blood sugars come down? Of course.If you don’t eat, will you lose weight? Of course. So, what’s the problem? None that I can see.

We can reverse type 2 diabetes and prediabetes today, right now, immediately. All without cost, without drugs, without surgery, with an all natural, time-tested healing method. We only need to lead our bodies down the healing pathway and have the courage to apply our hard-won knowledge.”

Dr. Jason Fung talks in-depth about controlling and reversing Type 2 diabetes with fasting in this full-length interview video with Dr. Joseph Mercola:

Reason 3: Fasting Regenerates Stem Cells in Old and Damaged Immune Systems

The University of Southern California reported that fasting protected the immune system and induced its regeneration by shifting stem cells from a dormant state to a self-renewal state.

The study which was published on June 5, 2014, in Cell Stem Cell, has implications for healthier aging because as one age, the immune system also declines. However, fasts between 2 to 4 days have shown to kill off old and damaged immune cells while regenerating new ones which will give the immune system a much-needed boost.


The researchers also found out prolonged fasting before chemotherapy also benefit those on such treatment protocols because it protects the patient from the toxicity of chemotherapy itself.

According to one of the researchers Dr. Tanya Dorff, assistant professor of clinical medicine at the USC Norris Comprehensive Cancer Center and Hospital,

“While chemotherapy saves lives, it causes significant collateral damage to the immune system. The results of this study suggest that fasting may mitigate some of the harmful effects of chemotherapy.”

Another researcher, Dr. Valter Longo, Edna M. Jones Professor of Gerontology and the Biological Sciences at the USC Davis School of Gerontology and director of the USC Longevity Institute says,

“When you starve, the system tries to save energy, and one of the things it can do to save energy is to recycle a lot of the immune cells that are not needed, especially those that may be damaged.”

What we started noticing in both our human work and animal work is that the white blood cell count goes down with prolonged fasting. Then when you re-feed, the blood cells come back.”

According to Dr. Longo, in the fasting process, the body gets rid “of the parts of the system that might be damaged or old, the inefficient parts, during the fasting. Now, if you start with a system heavily damaged by chemotherapy or aging, fasting cycles can generate, literally, a new immune system.”

So fasting forces the body to use up stored up glucose, fat, and ketones, and also breaks down a significant number of white blood cells. This white cell depletion process apparently triggers the regeneration of new immune cells.

The researchers found that in particular, fasting reduces the enzyme PKA and this seems to extend longevity. Prolonged fasting also reduced levels of IGF-1, a growth factor hormone which has been linked to aging, tumor progression, and cancer risk.

Reason 4: Fasting Lowers Heart Disease Rates

Medical News Today reported a study that showed folks who fasted for one day a month had lower rate of heart disease than those who did not.

The study was primarily on Mormons or members of the Church of the Latter Day Saints and was carried out by Dr. Benjamin D Horne, director of cardiovascular and genetic epidemiology at Intermountain Medical Center and adjunct assistant professor of biomedical informatics at the University of Utah in Salt Lake City, and his colleagues. Mormons fasted one day of every month because this is part of their faith.

Dr. Horne and his colleagues found that “fasting was the strongest predictor of lower heart disease risk and the patients who fasted also had the less coronary disease.”

The researchers surveyed 515 patients with an average age of 64 who underwent coronary angiography between 2004 and 2006; the results of the study showed that:

  • Patients who fasted were significantly less likely to have a CAD (coronary artery disease) diagnosis than those who did not (59% of the fasting patients had arterial blockage of 70% or more compared with 67% of the non-fasting patients).

  • People who fasted were 39% less likely to be diagnosed with CAD.

  • Patients who did not drink tea were less likely to have a CAD diagnosis. However, once fasting was factored in, the link between tea drinking and lower CAD became insignificant.

  • The impact of fasting was most strongly apparent when those patients with CAD were compared with those with minimal or no CAD (less than 10% arterial blockage).

  • The odds of having a CAD diagnosis was 45% lower among fasting patients.

While this was just a correlational study, other studies show fasting to:

Reason 5: Fasting Helps Battle Against Fatty Liver Disease

Researchers at Institute of Diabetes and Cancer (IDC) in Munich have discovered what happens at the molecular level when people go on a fast. Working with the German Center for Diabetes Research – DZD and the Deutsches German Cancer Research Center – DKFZ they were able to show that fasting produces a particular protein that regulates metabolism in the liver.

In the study that was reported in Medical News Today, the researchers found that lack of the gene of the protein GADD45β contributed to a higher likelihood of the development of fatty liver disease since it is GADD45β that controls the absorption of fatty acids into the liver. So a low GADD45β level promoted fat accumulation and storage in the liver as well as elevated blood sugar levels.


Prof. Dr. Stephan Herzig, Director of the Institute for Diabetes and Cancer (IDC) at the Helmholtz Zentrum München says, “The stress on the liver cells caused by fasting consequently appears to stimulate GADD45β production, which then adjusts the metabolism to the low food intake,”

So with fasting, GADD45β is produced, and this regulates the metabolism of fats in the liver.

Reason 6: Fasting Helps with Weight Loss

A review conducted by the University of Illinois, Chicago showed that fasting significantly decreased body weight by 3% to 8% over 3 to 24 weeks.

The detailed rates of weight loss in the review showed that intermittent fasting produced a weight reduction of 0.55 pounds or 0.5 kg per week while alternate day fasting showed better results at 1.65 pounds or 0.75 kg per week.

The people that took part in the review also lost 4% to 7% of waist circumference which indicates a reduction in both visceral fat and subcutaneous fat.

Short term fasting also increases the body’s metabolic rate as seen in this study as well as this study.

Dr. Krista Varady, Associate Professor of Nutrition at the University of Illinois at Chicago and author of the book: The Every-Other-Day Diet: The Diet That Lets You Eat All You Want (Half the Time) and Keep the Weight Off, recommends alternate day fasting for weight loss.

However, she also advocates eating only 500 calories a day on non-fasting days. According to Dr. Varaday,

“It takes about a week to 10 days or so to get used to that up-down pattern of eating.” “But it’s amazing. Even though people struggle through the first week, they always say, ‘After a week, I had no problem eating just 500 calories every other day.”

500 calories a day is really low and personally, I wouldn’t recommend such a low intake of food without medical supervision. Participants of Professor Rod Taylor’s famous 600 calories a say diabetes reversal diet were closely monitored by his team of researchers and doctors at the Newcastle University.

Closing Thoughts

Folks who are on LCHF and are fat adapted i.e. the body is using fat as its primary energy source rather than sugar will find it much easier to fast than those who are on the mainstream low-fat, high carb diet.

How to tell if you’re fat adapted? If you’ve been on LCHF for some time and can miss a meal without feeling ravenously hungry and irritable (a symptom of craving for carbs), then you’re fat adapted.

If you’ve just started on your LCHF journey, give yourself some time for your body to be fat adapted before trying out fasting. For those who are fat adapted and are keen to try out fasting, I would strongly recommend that you buy and read Dr. Jason Fung’s book, The Complete Guide to Fasting.

I wouldn’t recommend fasting for folks with Type 1 diabetes and ladies who are pregnant or breastfeeding their babies. You want to start on LCHF but don’t have a clue on how or where to start? I can help you; just send me an email:

Galen Chay
Founder at Fit and Healthy Beyond 50
Galen Chay is founder of Fit and Healthy Beyond 50, a website dedicated to helping men and women especially those above 50 to stay healthy and prevent chronic illnesses through dietary and lifestyle change interventions. He has been actively involved in health and fitness forums since 2007. Those he has come into contact with have improved their health through his online conversations with them, many of whom aren't even 50 yet but have been put on medications by their doctors for chronic conditions like diabetes, metabolic syndrome, obesity and heart disease.