Last Updated on April 12, 2024 by Fasting Planet
Few fasts last forever. With intermittent fasting especially, the expectation is that your fasting period will go on for a certain amount of time, then stop, then continue again. If you’re trying to fast for multiple days and you’re struggling, is it okay to ingest a very small amount of food? How many calories would break your fast?
A fast is considered broken once you consume calories. Some fasters believe staying within 50 calories or fewer is fine, but once you eat any calories at all, your body begins using glucose from the food instead of burning fat for energy.
In this in-depth article, we’ll tell you everything you need to know about breaking a fast. From whether supplements affect the fast to which foods to consume post-fast, you’ll learn to make smart, healthy decisions. After all, the time following your intermittent fast is incredibly important, and now you’ll know just how to manage it.
How Many Calories Break a Fast?
The Misconception
There’s an article on James Clear’s website about lessons he learned when he intermittent fasted for a year. If you’re not familiar, Clear is a photographer, entrepreneur, and author who is quite passionate about fasting.
For the 10th lesson in the article, Clear writes this: “as long as you stay under 50 calories, you’ll remain in the fasted state.” Even Clear mentions that he’s “not sure where this number came from,” but that he’d noticed it had been “dished around by enough reputable people” that he felt comfortable using it himself.
This article seems to be where the misconception came from that it’s okay to consume 50 calories a day without breaking a fast. Although you might not think so, 50 calories can take you pretty far. Here’s a list from BBC that includes both sweet and savory dishes that meet the caloric threshold or are under.
- Coffee made with 150 milliliters of skimmed milk
- 17 grapes
- 10 cherries
- 15 cherry tomatoes
- 10 brined olives
- A miso soup sachet
- An oatcake
- 15 grams of air-popped popcorn
- 35 grams of celery with a soft, light cheese
You can sip several beverages for 50 calories and under, although not many. Black coffee, vitamin water, La Croix, and hot chocolate when made with half a cup of almond milk, two Stevia packets, and a tablespoon and a half of cocoa powder fit the bill. The milk in the hot chocolate is 12.5 calories and the cocoa powder 15 calories, which still gives you about 20 calories to spare.
The Facts
Not all intermittent fasts are about foregoing food entirely. Many allow you to eat, such as the 16:8 method or a variation on it, in which you have at least eight hours a day for food consumption.
If you’re on the 16:8 fast or the 5:2 diet, where you’re supposed to eat 500+ calories for two days of the week, then the above 50-calorie foods and drinks are great. You can feel relatively full and nourished without eating a huge number of calories.
If you’re on a water fast, a dry fast, or an alternate-day fast, eating any calories during the fasting period absolutely counts as breaking the fast.
An article published in 2019 on health resource Furthermore says that “some intermittent fasters (optimistically) believe it’s okay to consume 50 calories without breaking their fast.” The writer spoke to Massachusetts performance nutrition coordinator at Precision Nutrition, Adam Feit, CSCS about how many calories break a fast.
Feit notes how ingesting calories in even small quantities interrupts our body’s ability to torch fat. “During a fast, you want the body to use the stores that are already there, including glycogen from muscle tissue,” Feit said in the article.
To understand why, you only need to know how intermittent fasting works. This is something we’ve covered on our blog before, but it’s worth a recap now.
Each time you ingest food, such as when you’re not fasting, it gets digested in your stomach. As the stomach combines what you ate with enzymes and acids to break the food down, something else happens. The starches, sugars, and carbohydrates in the food become glucose.
Glucose, as our blog readers know, is our body’s main source of energy. What glucose doesn’t get used as energy is then sent to the liver. Glycogenesis occurs, converting that glucose into glycogen that’s kept in your liver.
It’s possible for your body to stop burning glucose and start torching fat instead, sort of like turning on a light switch. To make it happen, you have to deprive yourself of carbohydrates, such as through a ketogenic diet or intermittent fasting. Ideally, you shouldn’t consume anything for a few days.
When you don’t eat on a water fast, an alternate-day fast, or a dry fast, you’re no longer providing your body with glucose. However, your body needs energy, and it has to pull that from somewhere.
Thus, it begins using the glycogen reserves in the liver. It is possible to deplete these completely, but it can take 12 hours for experienced fasters to do it. For first-timers, it may be longer depending on how much glycogen you have stored.
There’s no more glucose to go around, but your body still needs energy. It’s also out of stored glycogen, so now what? It begins pulling from your body fat, burning this for fuel. Sometimes, muscle proteins are burned as well, which is why we always advocate for exercise during intermittent fasting if you can. Otherwise, you’re at risk of muscle mass loss during a prolonged fast.
When you start burning fat, you’ll look trimmer and more toned. Combine this with the natural weight loss that comes from consuming zero calories and it’s no wonder intermittent fasting is so effective for body transformations.
Knowing all this, it should make more sense why you don’t want to eat even 50 calories when intermittent fasting. Any amount of food consumption will add more glucose to the body. This prolongs the amount of time it takes to trigger your body into burning fat.
Do Supplements Break a Fast?
What if you take daily multivitamins and other supplements? Will continuing to consume these affect your fast in any way?
It’s hard to say, so our answer is it depends. A slew of supplements could break a fast but aren’t very likely to. Here is an overview of these.
- Prebiotics and probiotics: Carb and calorie-free, it should be fine to take prebiotics and probiotics when intermittent fasting.
- Pure collagen: If you’re seeking to burn fat during your intermittent fast, pure collagen shouldn’t interrupt this. That said, your body’s ability to recycle old and damaged cell parts, also known as autophagy, may be interrupted.
- Creatine: This supplement should be okay to continue taking on an intermittent fast.
- Micronutrients: Certain micronutrients should be consumed with food so they absorb better. These include vitamins K, E, D, and A. B vitamins and potassium might be better to take when fasting.
- Algae and fish oil: With no carbs and calories, you don’t have to omit algae and/or fish oil on an intermittent fast.
- Multivitamins: Double-check that your multivitamin doesn’t have calories, added fillers, or sugars. If it doesn’t, then continue ingesting it as usual without risk of breaking your fast.
These supplements probably would count as breaking a fast, so proceed carefully:
- Supplements with sugar: Sugar can masquerade as many names, including fruit juice concentrate, cane sugar, pectin, maltodextrin, and more. Avoid any supplements with these ingredients.
- Protein powder: Protein powder may help when building and maintaining muscle, but the calories in it will break your fast.
- Branched-chain amino acids: Autophagy stops when you consume BCAAs due to the insulin response they encourage in the body.
- Gummy multivitamins: The fat, protein, and sugar in these multivitamins make them a poor choice to take during an intermittent fast.
If you don’t see your supplements on the list above, we recommend calling your doctor and getting their opinion about whether the supplement would break your fast.
When Should You Break a Fast?
That brings us to the next question you may have about fasting. If you can’t ingest calories during most types of intermittent fasts, then when are you allowed to?
You can break the fast when you’re ready for the fast to end or when the allotted time has passed. For example, let’s refer back to the 16:8 method, which we mentioned before. On that intermittent fast, you go 16 hours without food. You’d wait for those 16 hours to elapse and then you can eat again.
With an alternate-day fast, you’d go a full 24 hours without food and then another 24 hours on your regular diet. If you’re fasting for a medical test, you may have to wait six to 12 hours before you can eat and/or drink caloric beverages (at least most of them). In those instances, it’s especially important to refrain for the allotted time. The consumption of food and beverages can influence test results.
Ramadan, an Islamic religious observance, requires that all who participate fast from sunup to sundown. That includes foregoing both food and water.
If you’re on a water fast, then it’s up to you to decide when you want to break the fast. As we always say, beginners should start with a shorter fast, such as one that’s 12 hours, maybe 16 hours. The more often you successfully fast, the longer you can stretch your fasting periods, such as 48 hours and even 72 hours.
Do make sure you see your doctor for their approval before you begin the fast.
What Happens if You Break a Fast Early?
Perhaps you’re intermittent fasting as you’re reading this. You had seen the James Clear article and other sources that say it’s okay to eat 50 calories while intermittent fasting, so that’s what you’ve been doing. You now realize you have accidentally broken the fast.
If you’re fasting for your own personal reasons, such as weight loss, a stronger immune system, or a bodily reset, then now you know better. There’s nothing you can do to fix the fast you broke. We recommend you wait a few days and try another intermittent fast when you feel ready. This time, make sure you refrain from ingesting calories if those are the rules of your fast.
Ramadan includes Iftar, a nightly meal that effectively breaks that day’s fast. According to Islam rules, if you’re in good health, there is no reason to stop fasting early. Doing so is seriously punishable, and other religions may have similar rules.
As we said before, if you break a fast when testing for cholesterol, triglycerides, and diabetes, you could skew the results. These inaccurate results then influence the treatment your doctor prescribes, which can be potentially dangerous.
There are some situations when you may need to stop a fast early, and we’ll talk about those later. If you absolutely must maintain a fast for religious or medical reasons though, then we suggest going to sleep if you can. It passes the time and keeps you away from the refrigerator.
What Should You Eat When Breaking a Fast?
Your intermittent fast has ended, so it’s time to get right back into your prior diet, right? Not so fast.
We’ve written about this once before, but jumping into three meals a day–and big, heavy meals at that–puts you at risk of refeeding syndrome. This condition affects those who have fasted or are malnourished.
All that food so quickly triggers cell production of protein, fat, and glycogen. However, the phosphorous, magnesium, and potassium concentrations in your blood decrease to such a point that it’s possible to have heart failure. Other symptoms include heart arrhythmias, seizure, an increase in blood pressure, breathing issues, confusion, weakness, and fatigue. As you may have guessed, refeeding syndrome can be fatal.
That’s why it’s much better to ease your way back into eating. Here’s what to do.
Right After the Fast
Immediately upon ending the fast, you should eat about every two to four hours, but the quantities should be smaller. It’s fine to begin with a mostly liquid diet that includes bone broth, smoothies, vegetable juices, and/or fruit juices. The latter two should be homemade so you can control sugar quantity.
Vegetable soups are a great meal to eat at this point, too. Try making sautéed spinach, a broccoli smoothie, zucchini soup, beetroot soup, leek and potato soup, lentil soup, or cabbage soup.
If you want something a bit more solid and substantial, you might try a salad, such as a white bean salad, a cucumber pepper salad, or a cabbage carrot salad. Cooked and uncooked vegetables are suitable as well, as are fruits.
Healthy fat sources are also good to ingest after an intermittent fast. Try ghee, grass-fed butter, eggs, avocado, olive oil, and coconut oil. You can also eat fermented foods like sauerkraut, kefir, and unsweetened yogurt.
The above foods come so highly recommended because they’re not only nutritious, but they’re easily digestible, too. You’ll load up on the minerals and electrolytes your body was maybe missing during the intermittent fast and feel much better for it.
Later That Day/the Next Day
By the time you’ve reached your third meal, you want to start moving onto foods that take longer to digest. These will be more substantial but still aren’t big, heavy meals yet.
Fish and grass-fed poultry and meat should fill you up a bit. Pastured eggs are good to eat at this point, as are seeds and nuts. Whole beans and grains should be sprouted or soaked so you can digest them easily. Raw vegetables and fruits are also still recommended.
The Day After That
About 48 hours after your fast, maybe even sooner, you’ll probably feel comfortable enough to reintegrate staples of your regular diet into what you eat. That should be fine at this point, but listen to your body as you eat. If you feel uncomfortably full earlier than usual, pause eating or stop entirely. You’re not a high risk for refeeding syndrome by now, but it’s still better to be safe and cautious.
Signs You May Need to Break a Fast
There may arise a situation where you don’t necessarily control when you get to end the fast. If you have the following symptoms, then you either need to take a break from fasting or stop entirely. We’d advise you to get in touch with your doctor, too.
Menstruation
If you’re a woman who isn’t scheduled to have your period and it begins during an intermittent fast, that can be troublesome. Bodily changes can cause menstruation to occur early, but it’s still a good idea to put the kibosh on your fast and talk to your doctor or OB/GYN about what you should do going forward.
Stomach or Chest Pain
Both stomach and chest pain are abnormal symptoms of intermittent fasting. Whether you have one, the other, or both, you need to take a break from your fast and get back to it when and if you’re feeling better.
Burning Feeling in the Stomach
The same goes if you feel a strange sensation in the stomach akin to burning. This transcends hunger pangs into something else entirely.
Diarrhea
Since you’re not eating, making bowel movements may become less frequent than once a day when intermittent fasting. Diarrhea is certainly not something you should experience on your fast, so it’s time to stop the fast if you’re going to the bathroom a lot.
Vomiting and/or Nausea
Your stomach may begin to hurt a bit from hunger, but you shouldn’t feel nauseous like you’re about to be sick. If you are indeed vomiting, that’s another blatant signal it’s time to quit your fast for the time being.
Severe Dizziness
Minor wooziness is also to be expected as you deprive your body of glucose for energy. If you feel so dizzy you can’t even stand up straight though, that’s considered a major problem and possibly even a health emergency.
Unconsciousness
If you’ve fainted, then your blood pressure may have dropped too low. It’s time to quit your fast for sure.
Conclusion
The minute you consume a calorie when doing most kinds of intermittent fasting, you’ve broken the fast. There’s a misconception floating around the Internet that 50 calories a day is permissible, but it isn’t. Even that small number of calories interrupts processes like fat burning.
Now that you know what breaks your fast and what doesn’t, you can be safe, smart, and healthy on your intermittent fasts going forward. Best of luck!