Intermittent fasting, also known as “IF,” is a relatively recent fad that is simple to implement into any diet. It focuses on pacing your food intake to promote long-term weight loss outcomes and enhance overall health.
Due to the special advantages of fasting, keto dieters frequently incorporate intermittent fasting programs into their diets. It can also be used as a quick trick to get into ketosis or a way to break through weight loss plateaus.
However, there are still uncertainties regarding the length, volume, and frequency of our keto intermittent fasting.
Let’s take a closer look at the following fasting topics to learn everything you need to know about this remarkably simple tool:
Intermittent fasting: What is it?
When you eat intermittently, you alternate between a feeding state and a fasting state.
When you consume calories, your body is in a feeding state, and when you do not, it is in a fasting state (i.e., when you are between meals without any snacks or calorie-containing beverages).
Numerous different biological processes in the body are stimulated by each state. For instance, prolonging the fasted state increases autophagy, lowers insulin levels, increases fat burning, and encourages ketone production.
Below, we’ll learn more about these mechanisms and the health advantages of intermittent fasting. But let’s first get a better understanding of what “IF” actually looks like.
Overview of Common Keto Fasting Regimens and Intermittent Fasting Techniques
How to begin a fasting cycle
There are countless variations on intermittent fasting. These are the most typical techniques:
avoided eating. This happens when you skip a meal in order to extend your fast. Most people opt for breakfast, but some people would rather forgo lunch or dinner.
daily one meal (OMAD). It’s as easy as it sounds: Eat only one meal each day, then go without eating until the next.
consume windows. The 16/8 schedule is the most popular eating window schedule. Simply put, this means that you will consume all of your macronutrients within a window of eight hours. You will be fasting for the following 16 hours (i.e., consuming no calories whatsoever). Many people on keto diets will decrease their eating window and increase their fasting window as their bodies adjust.
Fast keto coffee. An excellent IF approach for those new to keto. Simply substitute a cup of Bulletproof or Ketoproof coffee for breakfast to see if you can extend your window of fasting until dinner. You will still be fasting from carbohydrates and protein, which offers many of the same advantages as intermittent fasting even though it isn’t a true fast (because the beverage contains fat calories).
24-48 hour purging. This extended fast may also be known as “every other day fasting.” With this fasting plan, you’ll have one or two days of fasting followed by a day where you can eat as much as you want.
We do not advise beginning with a prolonged fast of 1-2 days. Instead, try limiting your eating to a certain time of day (and use ketoproof coffee as needed).
Typically, people limit their eating to an eight-hour period between noon and nine o’clock or noon and eight o’clock. You can try longer stints of 18–24 hour fasting once you get the hang of eating on a schedule.
However, if you have trouble skipping breakfast, try the keto coffee fast. This may increase your ketone levels and help you naturally stifle your appetite.
You can choose to exercise daily, once per week, or twice per week. There is no perfect intermittent fasting strategy, so follow your gut and pay attention to how your body feels.
Do not force yourself to fast if it doesn’t work for you. On a ketogenic diet, weight loss and health improvement are possible without intermittent fasting. Realistically limiting yourself serves no purpose; it is not worthwhile if it causes you to be unhappy and unwell.
What Happens When You Intermittently Fast?
The whole idea behind intermittent fasting is to give ourselves permission to increase how much food we can eat at once. We are putting a cap on the number of calories we can consume because our bodies can only absorb so much food at once.
For those who overeat, this is a great strategy. People often wonder why they are gaining weight because they don’t keep track of the snacks they eat throughout the day.
You’ll find that you’re not as hungry as you once were after your body adjusts to fasting. This enables you to accurately maintain and record the nutritional values of what you consume.
Our bodies can break down extra fat that has been stored during this fasting period to provide the energy they require. Because there is little to no glucose in our bloodstream when we are in a ketosis state, our bodies are already mimicking a fasting state and burning body fat for energy.
The same logic underlies intermittent fasting; instead of drawing energy from the fats we consume, we use fat that has been stored in our bodies. You might think it’s fantastic that you can simply fast and lose more weight in light of this, though. You must keep in mind that in the future, you will have to consume more fat to meet your daily macronutrient requirements (the most important thing). If you consume too many fats in this area, you will store the extra.
Fasting has some benefits for weight loss, but they are more for timing convenience. If you don’t enjoy fasting, don’t do it just to lose weight. But there are other advantages as well, which we’ll talk about as well.
Why Meal Timing Matters When Intermittent Fasting
Food timing is important
Simply put, intermittent fasting is a dietary practice in which you limit the time during which you eat. One of the most popular methods of intermittent fasting, for instance, involves fasting for 18 hours and eating during the final 6 hours of the day.
Consider that you didn’t eat anything else after your last meal at 6 o’clock last night. Simply limit your eating until 12 pm the next afternoon to implement an intermittent fast (yes, sleeping time counts as fasting time). You can do this every day by eating only from 12 to 6 p.m. and fasting the rest of the time.
Intermittent fasting also comes in a wide variety of forms. Well-known ketogenic diet researcher Dr. Dom D’Agostino advises performing longer intermittent fasts for three days, three times a year. This entails skipping meals for three days before eating normally until the following fast.
Including intermittent fasts of at least 16 hours per day in your routine is another way to try fasting for yourself. This approach makes it much easier for you to reap the rewards of cutting back on calories for a short period of time.
Even though this idea is straightforward, it might not be immediately clear how intermittent fasting can help you, especially if you are already experiencing the benefits of the ketogenic diet.
Interestingly, combining the keto diet with intermittent fasting improves results, creating a positive feedback loop. Let’s examine this tactic’s operation and potential advantages in greater detail to gain a clearer understanding of what I mean.
Ketone Production, Insulin Reduction, and Induction of Autophagy: How Intermittent Fasting Functions
Intermittent fasting aids in weight loss by making it more difficult to overeat during the day. A straightforward rule, such as “skip breakfast” or “only eat between 5 and 8 pm,” can assist in preventing you from reaching for snacks or consuming calorie-dense beverages throughout the day, which can lead to weight gain.
Even if you do develop a voracious appetite while fasting, it will be difficult for you to eat too much. Intermittent fasting actually tends to lower daily energy intake and encourage fat loss.
This indicates that if you stick to a condensed eating window or a finite number of meals, you may be able to eat as much as you want and still achieve your goals.
Your body will need some time to get used to this new eating routine when you first start intermittent fasting. At first, you might experience intense hunger pangs and strong cravings, but they will soon pass as your cells start to gorge on ketones and stored fat.
Insulin reduction, ketone production, and autophagy are the primary mechanisms underlying your capacity to fast, shed pounds, and maintain good health throughout the process. Our insulin levels gradually decline over the course of a fast. This encourages fat release from our fat cells and activates the ketogenesis process, which produces ketone bodies.
As your fast continues, you’ll go deeper into a state of ketosis, increase your ability to burn fat, and speed up the autophagic, or body’s own cleaning process.
A Nobel Prize-Winning Lifestyle “Hack”: Autophagy
Yoshinori Ohsumi received the Nobel Prize in Physiology or Medicine in 2016 for unraveling some of the mechanisms underlying autophagy, the process by which cells eat themselves. On the surface, this seems like a terrible thing for our cells to do, but think about what is actually happening.
Non-essential components, such as damaged proteins, are recycled during the autophagy process in our cells, and invasive microorganisms and hazardous substances are eliminated. This indicates that autophagy is crucial for slowing down the aging process, treating disease, and preventing cancer, but it isn’t always present.
The three main methods that can start various autophagic processes are fasting, protein restriction, and carbohydrate restriction; however, none of these three are identical. This helps to explain why a ketogenic diet has so many beneficial effects and why intermittent fasting is a way to further enhance your diet.
Even though this is a good enough reason to fast more frequently, autophagy isn’t the only benefit of IF. In fact, a wider range of advantages can come from combining the ketogenic diet with fasting.
The Benefits of Intermittent Fasting Supported by Science
The benefits of limiting our food intake go far beyond just weight loss, and include things like better blood sugar control, improved body composition, and even potential benefits in the treatment of cancer and diabetes. Here are some of the benefits of intermittent fasting while following a ketogenic diet:
1. Improved Insulin Sensitivity and Blood Sugar Control
Giving your body a break from calorie consumption every now and then can help lower blood sugar levels and increase insulin sensitivity.
This makes it a valuable tool for preventing type 2 diabetes. In fact, one clinical trial discovered that maintaining the same calorie deficit with six meals per day may not be as effective as intermittent fasting.
Together, the two dietary approaches can work synergistically to improve blood sugar regulation and lower insulin levels. The keto diet has also been shown to help with insulin resistance and type 2 diabetes. However, more analysis is required to determine how combining them will affect outcomes.
2. Better Body Composition and Lower Body Fat Percentage
In a review of the research on intermittent fasting published in 2014, it was discovered that intermittent fasting alone can help people lose weight at a rate of about 0.55 to 1.65 lbs (0.25-0.75 kg) per week. They lost belly fat as a result, as evidenced by a 4-7% decrease in waist circumference.
An alternate-day fasting protocol was found to reduce body fat by up to 16% over the course of 3–12 weeks, according to another review of IF research. The researchers came to the conclusion that “these diets are equally effective in decreasing body weight and fat mass, although [alternate day fasting] may be more effective for the retention of lean mass” after comparing this result to daily calorie restriction.
In other words, compared to continuous calorie restriction, intermittent fasting may be more effective at lowering our body fat percentage.
3. Better Mental Clarity
Your body can run on fat and ketones, which are the most energy-efficient fuels, and your brain uses a lot of energy. Your brain can successfully function on ketones, which are produced when fat is broken down in the liver, once your body has become keto-adapted.
Our energy levels usually balance out when our brain uses ketones, resulting in less mental fatigue and greater focus. Because of this, people following a ketogenic diet report experiencing constant energy throughout the day as opposed to the ups and downs that we typically experience when following a high-carb diet.
One of the simplest ways to increase ketone production and gain the mental clarity that ketone burning provides is through intermittent fasting.
As a result, you might discover that you naturally work harder before you eat your first calories of the day.
4. May Improve Fitness Results Overall
People frequently believe that if you don’t eat before and after exercising, you’ll lose muscle.
When you have become accustomed to ketosis, this is even less likely to be the case.
Fasting while exercising has a number of long-term advantages, such as:
Higher metabolic adaptations – Research indicates that training while fasted will increase your training performance over time.
Improved muscle synthesis – Research indicates that when you train while fasting and use the right nutrition, your chances of gaining muscle are increased.
Faster nutrient absorption following a fasted workout has been shown to improve response to post-workout meals, according to studies.
Muscle and IF
Numerous studies on fasting while training have been conducted, one of which focused on Muslim athletes during Ramadan. You shouldn’t be concerned because it was determined that training while fasting has no effect on performance.
5. simplifies your keto diet and makes it easier to maintain weight loss
The most challenging aspect of any diet is maintaining weight loss results. To restrain ourselves, we frequently rely on willpower, which is never effective over the long term. It is better to use straightforward weight loss techniques that come naturally to you rather than solely relying on restriction.
Intermittent fasting is the ideal illustration of this for some. They simply adhere to a straightforward fasting schedule that fits their schedule and discover that gaining weight is harder than maintaining weight loss.
You might discover that incorporating intermittent fasting into your keto or low carb diet relieves some of the stress associated with meal preparation and planning while also helping you lose belly fat.
But keep in mind that this is just one type of weight-loss aid. You can try dozens of other tactics and cheats that might be more effective for you.
Muscle and Intermittent Fasting
Fasting reduces muscle loss.
Recently, two groundbreaking studies on the effects of intermittent fasting on men were released. One research team looked at the effects of 16 hours of intermittent fasting on weight-lifting males. They discovered that while fat mass significantly decreased, muscle mass remained stable and that males who fasted for 16 hours per day burned more fat for energy than those in the control group, who only fasted for 12 hours.
Another study found that consuming about 650 fewer calories per day than usual allowed for an increase in muscle mass, strength, and endurance after 20 hours of fasting and resistance training.
Even untrained overweight and obese people can benefit from intermittent fasting. One study found that eating fewer calories is effective for losing fat, but it does result in some muscle loss (Obesity Reviews). For a period of 12 weeks, the subjects lost significantly less muscle mass if they followed a 24-hour fast followed by as much food as they wanted the following day.
You read that right: these subjects were able to maintain more muscle mass than the subjects who consumed fewer calories per day without fasting at all during the 24-hour period of intermittent fasting without resistance training. Although this result defies common sense, we can uncover the mechanism underlying it by learning more about autophagy.
Autophagy and the Prevention of Muscle Loss
Yoshinori Ohsumi won the Nobel Prize, but other researchers were already making important advancements in the field of autophagy. Autophagy Is Required to Maintain Muscle Mass is the title of a 2009 article that appeared in the journal Cell Metabolism. Researchers in this study described how deactivating a crucial autophagy gene caused a significant loss in muscle mass and power.
This occurred because muscle cells’ autophagy is required to clean up harmed proteins and mitochondria. The proteins and mitochondria will continue to be damaged if autophagy is never activated, and the muscle cells will start to die, resulting in a loss of muscle and strength.
Muscle loss and Autophagy
This seems counter-intuitive because we believe that the nutrients we consume will undo the harm, but when you consider it another way, it makes sense.
It is best to clean the room and remove the old furniture before putting the new furniture in if you want to renovate a room. Your cells think in the same way as you do. Before placing new furniture, we must use intermittent fasting to allow autophagy to purge the cell’s interior. Our cells may develop cancer if we don’t.
Cancer and Intermittent Fasting
Although there is little to no research on how 2 or 3 day fasts affect muscle loss in humans, there are numerous clinical trials being done right now to see how fasts affect cancer patients.
In the first round of case studies, chemotherapy patients voluntarily fasted for 48 to 140 hours. Regardless of how long they fasted for, each person reported fewer side effects and an improved quality of life.
This may imply that fasting for two to seven days can protect the body’s cells from toxicity when it is present in high doses.
Cancer and Fasting
According to other animal studies, fasting may be just as effective as chemotherapy in slowing the growth of various tumors and improving the activity of chemotherapy against melanoma, glioma, and breast cancer cells. Even though the results of this research might not be applicable to your situation, they do indicate that intermittent fasting may be able to support your body during toxic stress.
The Benefits’ Mechanisms Simplified: Autophagy, Ketones, and Fat Loss
Because it allows you to restrict calories, cause ketosis, and trigger the autophagic processes brought on by protein restriction and starvation, intermittent fasting is incredibly effective.
If the terminology is confusing you, consider how long it takes you to tidy up your room. Even if you set aside a specific period of time on the weekend to clean it, what happens when the weekend actually arrives?
When tasks or chores arise, you give them lower priority. Your room is slightly dirtier than usual after a week without cleaning, but it is filthy after a month of being too busy.
Fasting can help your body’s cells get clean.
When we eat three or more meals a day that completely satisfy our daily calorie requirements, this is what happens to our cells. What can you do if your cells still fill up with toxic substances and non-essential proteins despite eating only the healthiest foods?
You fast from being consumed by other obligations rather than from food to make sure that you actually clean your bedroom. You must abstain from food in order to ensure that your cells can cleanse themselves.
In addition to starting your cells’ clean-up process, fasting will also boost your ketone production and encourage fat burning. Simply put, you can experience the advantages of a ketogenic diet and autophagy more quickly by incorporating intermittent fasting into your routine.
Furthermore, you can increase ketone levels, burn more fat, and increase autophagy more than you would with intermittent fasting alone if you start combining it with exercise (like walking, cycling, or lifting weights).
Overall, the evidence for intermittent fasting suggests that it would be a great addition to the keto lifestyle for most people, whether or not you add exercise. But before you get started, it’s crucial to be aware of any potential side effects.
How much time can we go without food?
When you first begin fasting, you might experience extreme hunger and be overcome with visions of your muscles vanishing into thin air. This is simply how your mind responds to the possibility of starvation; even though it may feel as though you will lose all of your muscle and starve, this is not necessarily the case.
Mahatma Gandhi actually managed to go for 21 days without eating while only consuming small amounts of water. People were able to live for 10 to 14 days without any food or water during those times. These are only anecdotes, though; what does the science have to say?
Humans have the ability to survive even longer than Gandhi did during his fast, according to numerous studies conducted during hunger strikes and religious fasts.
How long can we go without eating?
For instance, one monk planned to keep up with his daily activities in the monastery while observing a 40-day fast under medical supervision. After 36 days, “profound weakness” and low blood pressure while standing forced the medical staff to intervene. Although the monk fasted for 15 days longer than Ghandi did, the fast was broken just in time for the man to recover.
33 political prisoners who were on hunger strikes were monitored by another study. Prior to being hospitalized for dehydration due to an inadequate intake of fluids and electrolytes, the prisoners went on a fast for six to twenty-four days (not because of starvation). They were told that breaking their fast was “uncomplicated.”
As your body tries to trick you on the first day of your fast, keep these studies in mind. Health issues are extremely unlikely to arise even after three days of fasting. But it’s important to be aware of any problems that fasting might bring on. You usually want to eat every day if you decide to include fasting in your daily diet. if necessary, fasting for longer periods of time.
Refeeding Syndrome: Should You Be Concerned?
When you fast or are malnourished for more than five days, some real health problems can occur. Refeeding syndrome, one of these complications, is brought on by potentially fatal changes in fluid and electrolyte balance that can occur when we eat after a period of undernourishment.
This occurs as a result of how heavily our diet influences the concentration of fluids and minerals in our bodies. The excretion of essential minerals like sodium and potassium is increased by low carbohydrate diets like the keto diet.
The ketogenic diet can cause you to lose an unhealthy amount of these crucial minerals if you combine it with a protracted fast.
a ketogenic meal high in minerals
Fasts shorter than five days, however, are unlikely to cause problems, particularly if you break your fast with a low-carbohydrate meal rich in foods that are rich in minerals. For instance, a meal of salmon, avocado, and dark leafy greens with some unrefined salt would be the ideal way to end a longer fast.
On the other hand, there is absolutely no need to be concerned about refeeding syndrome during a shorter fast of less than 24 hours.
That being said, it is essential to maintain a proper mineral balance and hydration while fasting (with the help of our article on keto supplement recommendations). You can lessen your chance of getting the keto flu by doing this.
Keto Flu, carb restriction, and intermittent fasting are potential drawbacks.
Our bodies excrete more fluid and minerals than usual when we restrict our carbohydrate intake (via fasting or keto eating). Fatigue, headaches, digestive problems, and other flu-like symptoms could result from not being meticulous with your electrolyte and water intake.
The majority of the time, this is simply a symptom of mild dehydration, which can be treated by consuming more water, sodium, magnesium, and potassium.