How It Works: Fast for 24 hours once or twice per week. During the 24 hour fast, which creator Brad Pilon prefers to call a “24 break from eating,” no food is consumed, but you can drink calorie-free beverages. After the fast is over, you then go back to eating normally. “Act like you didn’t fast,” Pilon says. “Some people need to finish the fast at a normal mealtime with a big meal, while others are OK ending the fast with an afternoon snack. Time it however works best for you, and adjust your timing as your schedule changes,” he says.
Although some of the intermittent fasting methods online seem more intense than others (some can last upwards of 48 hours), the beauty of intermittent fasting is that you get to choose and experiment with how long you fast. This not only allows you to determine how intermittent fasting can fit in within your lifestyle, but to discover the fasting sweet spot that helps you feel best physically.

When our cells undergo the process of autophagy, non-essential parts like damaged proteins are recycled and invading microorganisms and toxic compounds are removed. This means that autophagy plays an important role in stopping the aging process, reversing disease, and preventing cancer, but it doesn’t happen all the time. Fasting, protein restriction, and carbohydrate restriction are the three main ways that can initiate different autophagic processes — all of which are not the same. This is part of the reason why a ketogenic diet has so many positive effects, and it also shows you why intermittent fasting is a way to improve your diet even more.
Cons: Even though it’s nice to eat a few snacks rather than go without any food for 20-plus hours, the guidelines for what you need to eat (and when) can be hard to follow long-term. The strict schedule and meal plan may also interfere with social gatherings. Additionally, eating one main meal at night — while following strict guidelines of what to eat, and in what order — can be tough. It’s especially hard for those who prefer not to eat large meals late in the day.
Whichever option you choose, there's enough evidence to show that intermittent fasting has many health benefits. Dr. Palanisamy sums it up best by saying, "The final caveat is that some fasting is better than none. So if having a regular or even bulletproof coffee is the only way that you can stick with the practice of intermittent fasting, then it's probably worth it."

Keep in mind that when considering using pink Himalayan salt in your coffee, it really is more for taste than for the health purposes. Some experts warn that the best way to reap the benefit of the pink wonder is to place it directly on or under your tongue, so that it can be immediately absorbed into your system. Adding it to coffee or water would minimize that process.
So how long does it take to go into ketosis when fasting? On a standard keto diet, it typically takes around 2–3 days to reach ketosis, although it can take up to seven days in some cases. However, many people find that keto adaptation intermittent fasting can speed up the process and help your body burn through glycogen stores more quickly to help enter ketosis.
Jerimiah, the linked study in the article (https://www.sciencedirect.com/science/article/pii/S1550413118302535) specifically studied “eTRF”(Early Time-Restricted Feeding) from 8am – 2pm, and implies that eating earlier is better than later. I haven’t read the study (it’s behind a damn Elsevier pay-wall), so I don’t know how strongly they feel about early vs late, though. For me, personally, 12-8 is doable, and skipping dinner (given the existence of a family and the desire to have dinner with said family) isn’t doable, so I’m pleased to hear from you and April above that it’s working. Just starting!
Amy Shah, MD, is double board-certified doctor who received her medical training from Cornell, Harvard and Columbia Universities. She has a thriving medical practice in the Phoenix area, where she sees more than 5,000 patients each year. In 2015, Dr. Shah was named one of the “Top 100 Women in Wellness to Watch” by MindBodyGreen and was a guest on the Dr. Oz show.
What if we told you that the answer to losing weight, improving body composition, and feeling better isn’t about dieting, but instead skipping meals every once in a while? For some, intermittent fasting, or going a longer period of time — usually between 14 and 36 hours — with few to no calories, can be a lot easier than you may think. And the benefits might be worth it. If you think about it, all of us “fast” every single day — we just call it sleeping. Intermittent fasting just means extending that fasting period, and being a bit more conscious of your eating schedule overall. But is it right for you? And which method is best?
Instead of going 18 hours without food, brew Bulletproof Coffee beans in the morning, and blend it with a nice big hunk of grass-fed butter and Brain Octane Oil for breakfast with no carbs or protein. If you use mold-tested Bulletproof Coffee beans, you have a satisfying, low-toxin coffee that doesn’t cause adrenal stress the way most coffee does, and it tastes like a creamy latte.
How It Works: Warriors-in-training can expect to fast for about 20 hours every day and eat one large meal every night. What you eat and when you eat it within that large meal is also key to this method. The philosophy here is based on feeding the body the nutrients it needs in sync with circadian rhythms and that our species are “nocturnal eaters, inherently programmed for night eating.”
And while this may sound difficult, it’s really not. After all, the reasons our bodies store fat in the first place is because we, as a species, aren't really designed for constant eating. The three-square-meals (or more) eating plan is a relatively new phenomenon in human history; for much of our past, feast and famine were the order of the day. Our bodies know how to handle long stretches without food, and they know how to make good use of the “feasts” when they come along.
Before you start your IF plan, it's important to talk with a professional to make sure it's right for you. Women should be especially cautious as there are some mixed opinions on whether or not certain fasting protocols are healthy for female hormone balance. In addition, if you have adrenal fatigue or gut health issues you'll want to proceed with caution. If you have a history of disordered eating, you'll probably want to avoid fasting altogether..
On the flip side of that, eating keto can make your periods of fasting more manageable. For example, someone who is eating a diet higher in carbs will likely have more discomfort with intermittent fasting as the body constantly switches between glucose for fuel and ketones for fuel. By continuing to eat keto even during feeding periods, you can keep your body constantly running on ketones.
Fasting on keto can be incredibly beneficial, especially if you’ve reached a plateau and aren’t seeing results from the ketogenic diet alone. While it’s not required, keto intermittent fasting can bring the benefits of your diet to the next level and help optimize your health. It is also thought to speed up ketosis by helping your body burn through glycogen stores more quickly, which can help sidestep symptoms of the keto flu to get faster results.
So what’s the first step in getting started? Each method has its own guidelines for how long to fast and what to eat during the “feeding” phase. Below, you’ll find the five most popular methods and the basics of how they work. Keep in mind, intermittent fasting isn’t for everyone. Those with health conditions of any kind should check with their doctor before changing up their usual routine. Note that personal goals and lifestyle are key factors to consider when choosing a fasting method.

And while this may sound difficult, it’s really not. After all, the reasons our bodies store fat in the first place is because we, as a species, aren't really designed for constant eating. The three-square-meals (or more) eating plan is a relatively new phenomenon in human history; for much of our past, feast and famine were the order of the day. Our bodies know how to handle long stretches without food, and they know how to make good use of the “feasts” when they come along.
Keep in mind that when considering using pink Himalayan salt in your coffee, it really is more for taste than for the health purposes. Some experts warn that the best way to reap the benefit of the pink wonder is to place it directly on or under your tongue, so that it can be immediately absorbed into your system. Adding it to coffee or water would minimize that process.
Intermittent Fasting (IF) was something I thought I’d try for maybe 2 weeks-like every other failed diet I had attempted. You name it, I’ve tried it! Weight Watchers, Atkins, Low-Carb, Keto, Protein-Power, Fat-Flush, South Beach, Fit by 50, Nutrisystem, Low-Calorie/High Fat, High Calorie/Low Fat, Counting Calories, Counting Macros, Counting Steps… I could name 20 more, but you get the idea.
Now that you’re properly prepared, it’s time to get started with intermittent fasting keto. In addition to cutting carbs, increasing fat intake and restricting food consumption to a specific window of time each day, you should also be sure to stay hydrated and plan your workout routine around your fasting schedule. While exercising is okay during days that you fast, it’s important to listen to your body and avoid pushing yourself too hard.

The thing is that if you want to slim down and get rid of excess pounds, then the fasted state is really the best way to do it. If you keep taking food into your body, insulin levels will remain high, and you will keep burning glucose for fuel instead of burning fat. Of course, to remain in the fasted state, you need to not be in the fed state, and that can be a problem. Starving yourself all of the time isn’t enjoyable, and it’s not healthy. To be blunt about it, your body needs nutrients, it just doesn’t need them all day, every day.
Perhaps most importantly, intermittent fasting is one of the simplest strategies we have for taking bad weight off while keeping good weight on because it requires very little behavior change. This is a very good thing because it means intermittent fasting falls into the category of “simple enough that you'll actually do it, but meaningful enough that it will actually make a difference.”
No cravings. Fat doesn’t spike your blood sugar levels. In fact, a keto diet is so effective at stabilizing blood sugar that it got type II diabetics off their medication entirely, according to a recent study.[15] If you pair a keto diet with fasting, your blood sugar will stay stable and low (but not too low) all day. Say goodbye to the cravings, fatigue, and mood swings that make high-carb fasting so difficult.
Intermittent fasting may work amazingly well for some people, and terribly for others. Most importantly, if you do decide to give intermittent fasting a try, be sure to listen to your body’s feedback. Easing into intermittent fasting by starting with shorter fasting windows can help with initial symptoms of hunger and discomfort. But if it becomes too uncomfortable, be honest with yourself, accept it, and move on.
Tons of celebs are jumping on the intermittent fasting keto bandwagon, and for good reason. The two work hand in hand to accelerate weight loss, not to mention stimulate lots of other performance-boosting benefits. Fasting is an extraordinary tool for improving your biology. It’s free. It’s universally accessible. It’s adaptable. It’s the reason it’s always been a major part of the Bulletproof Diet.
Hi Thea, That’s wonderful that IF has worked for you. Diets, and particularly fasting, can be very triggering for others with a history of an eating disorder. People who have been in remission can relapse. For more about what concerns and problems others have had, there is alot of information out there, and for starters I recommend this thorough article from Psychology Today: https://www.psychologytoday.com/us/blog/hunger-artist/201411/the-fast-diet-fast-route-disordered-eating
60 year old and just started IF a week ago. I eat from noon to 8pm. The noon start works for me because I’m not starting my day with the thought of food! I LOVE FOOD AND LOVE TO EAT! I am moving away from some bad habits and it doesn’t seem that difficult for me with IF! Just one week in and I do feel better. Can’t wait till I’ve got a month under my belt.
Another perk? There are no “forbidden foods,” and no counting calories, weighing food or restricting your diet, which makes it a bit easier to follow. That said, this isn’t a free-for-all. “You still have to eat like a grown-up,” Pilon says. It’s all about moderation: You can still eat whatever you want, but maybe not as much of it. (A slice of birthday cake is OK, he says, but the whole cake isn’t.)
As with any diet, you’ll get the best results if you’re consistent. At the same time, you can certainly give yourself a break from this kind of eating schedule on special occasions. You should experiment to figure out which kind of intermittent fasting works the best for you. Lots of people ease themselves into IF with the 12-12 plan, and then they progress to 16-8. After that, you should try to stick to that plan as much as possible.
Every study seems to support cognitive and health benefits for IF. Studies are coming out showing it may help stave off heart disease and it’s even been shown to halt or possibly reverse brain-related diseases such as Alzheimer’s. If in doubt, check out Jason Fung’s youtube videos along with a couple of youtube researchers who do wonderful analytics, an American who lives in Japan who goes by, “Things I’ve Learned” and Thomas DeLauer’s IF material. I’ve been doing IF myself for a few months now and I feel better, more energy, better sleep, and controlled weight.
×