Dr. Anthony Gustin is a board-certified sports chiropractor, functional medicine practitioner, entrepreneur, podcast host, and founder of Perfect Keto.
Just like the ketogenic diet, fasting has become a recent craze that more and more people are discovering works well for them. From health benefits to simply making life easier, regular fasting has a lot of advantages — and those advantages can be even greater when combined with a keto diet!
In this article, we’ll cover some basics of fasting and then dive into the benefits you can get from fasting while also eating ketogenic.
The Basics of Fasting
There are several types of fasting, but the one most widely used version today is known as intermittent fasting:
How Intermittent Fasting Works
Intermittent fasting (also commonly referred to as “IF”) involves only eating within a certain period of time. There are different forms of intermittent fasting, but the most popular is eating within anywhere between a 4- to 7-hour window.
For example, someone might choose to only eat between the hours of 12pm and 7pm, allowing their body to fast for 17 hours with a 7-hour “feeding” period. That window can be moved around as needed, but it guarantees that the time outside that window (including while you sleep) lets the body rest and fast.
Other variations of intermittent fasting include simply skipping meals or fasting for a few days at a time (Note that if you fast for several days, it’s best to do a modified fast, such as a fast mimicking diet, to avoid the chance of re-feeding syndrome from lack of vitamins and minerals).
Fasting occasionally or doing regular intermittent fasting has been shown to be just as beneficial for health as simply restricting calories. Intermittent fasting is much more doable for most people and is a great alternative to restricting calories.
Benefits of Fasting
Fasting is the body’s natural way of surviving even when there are periods of little to no food. Although this is hardly the case for us anymore, the benefits still hold true — and fasting our bodies on a regular basis helps us tap into those benefits, which include:
A healthier metabolism: Contrary to popular belief, fasting in the right way does not negatively affect metabolism. In fact, it can actually help improve metabolism and metabolic conditions like type 2 diabetes.
Lower inflammation: The body is using fat for energy instead of glucose when it is both fasting and in ketosis. This avoids spikes in blood sugar and insulin that can raise inflammation markers, create free radicals, and even trigger disease.
Autophagy: Fasting may actually help the body clean out and repair itself. Fasting helps boost the autophagy process when the body is not busy digesting food and releasing insulin all day long.
Now that we know there are many great reasons for fasting, let’s look at how the combination of fasting and ketosis can do great things for our health.
Benefits of Fasting on the Ketogenic Diet
While fasting itself has a multitude of benefits, fasting on a low-carb diet is even better for several reasons:
Ketosis While Fasting
Since being in ketosis means the body has been depleted of glucose stores (glycogen), you’re already using fat and ketones for energy. This means several things:
- It not only makes the body more efficient during fasting periods but also reduces any initial negative side effects (like keto flu or stomach upset) that someone eating a “normal” diet (high amounts carbs during feeding periods) can experience.
- Already being keto-adapted prevents the body from having to constantly switch back and forth from using glucose to using fat for energy.
In addition, eating a ketogenic diet before fasting can help you get into ketosis faster, which allows you to begin reaping the benefits sooner. Taking exogenous ketones during this period can also help speed up the process.
Weight Loss Benefits
As we mentioned above, if you’ve already been in ketosis for a while before beginning fasting, it means your body is already adapted to using fat and ketones for energy. Eating keto controls appetite and helps you stay fuller for longer, making it easier to get used to longer periods without food.
If weight loss is your goal with intermittent fasting and ketosis, the combination can be a great way to rapidly reduce weight. The fat burning capabilities of ketosis plus the natural reduction in calories from fasting (due to a naturally smaller eating window) provides a one-two punch for reaching (and maintaining) a healthy body weight, as well as pushing through a weight loss plateau.
Intermittent fasting also trains the body to get used to eating a day’s worth of calories within a smaller amount of time, which is good for promoting a healthy intake of food and calories for the day. One you’re used to fasting and also eating keto, you learn to eat only when hungry, not necessarily when it’s the standard time for a meal.
Even though you’ll be “breaking” your fast in between intermittent fasting periods, breaking it with a ketogenic diet means you’ll still be in fasting mode even though you’re eating food. By eating fatty ketogenic diet foods, your body continues as if it were fasting while also getting tons of nutritious foods and a sufficient calorie intake.
Periods of fasting combined with eating high amounts of carbohydrates can lead to brain fog and crazy swings in blood sugar, which is neither good for your body nor your brain. By running on ketones even while eating food, you can support your brain through ketosis and help prevent mood issues like depression.
Take Away Message
We should note that fasting is a not a requirement to be successful on a ketogenic diet. If fasting isn’t for you or if you have a history of disordered eating, you might be better off simply eating keto.
However, if you’re interested in leveling up your health and seeing what else can work for you, periodic fasting along with a ketogenic diet is an option. They complement each other very well and share a lot of amazing benefits for our bodies and health.