Some supplements and drinks may break a fast. This can depend on whether they contain certain ingredients, including sugar.


Fasting is becoming a popular lifestyle choice.

Fasts don’t last forever, though, and between fasting periods you will add foods back into your routine — thus breaking your fast.

It’s important to do this carefully, and certain foods are better than others.

Additionally, some foods, beverages, and even supplements can unintentionally break your fast, while others don’t have much impact.

This article covers which foods, beverages, and supplements are less likely to affect fasting periods and which are best when you’re ready to break a fast.

Intermittent fasting is an eating pattern that alternates periods of eating with periods of either not eating or taking in minimal calories. It emphasizes when you eat rather than what you eat.

Even though it has recently gained mainstream attention, intermittent fasting isn’t new. People have practiced periods of fasting throughout history, such as for spiritual, health, or survival reasons (1).

The intent of intermittent fasting isn’t necessarily only to restrict calories, but also to allow your body to focus on maintenance and recovery, rather than digesting.

Many fasting patterns incorporate regular 12- to 16-hour periods of fasting into each day, while others include fasting for 24 or 48 hours once or twice per week.

When you fast, your body undergoes a number of metabolic changes. After some time, fasting causes your body to enter ketosis, a state in which fat is used for energy when carbohydrates are unavailable (2, 3, 4).

Furthermore, fasting causes insulin levels to decrease. It also promotes autophagy, the process by which your body rids itself of unneeded, damaged, or harmful cells (5, 6, 7, 8).

There is evidence that intermittent fasting can be beneficial for weight loss, lowering blood sugar, improving heart health, reducing inflammation, and reducing your risk of chronic diseases (9, 10, 11, 12).

Summary

Intermittent fasting rotates periods of fasting and periods of eating. It’s often used for health purposes like weight loss and chronic disease prevention, though it’s been used historically for other reasons.

By definition, fasting means refraining from eating food. However, you may be able to consume some foods and beverages while still preserving the benefits of fasting.

Some experts say as long as you keep your carbohydrate intake below 50 grams per day during a fast, you can maintain ketosis (13).

Below are some foods and beverages you can consume while fasting.

  • Water. Plain or carbonated water contains no calories and will keep you hydrated during a fast.
  • Coffee and tea. These should mostly be consumed without added sugar, milk, or cream. However, some people find that adding small amounts of milk or fat can curb hunger.
  • Diluted apple cider vinegar. Some people find that drinking 1–2 teaspoons (5–10 ml) of apple cider vinegar mixed into water can help them stay hydrated and prevent cravings during a fast.
  • Healthy fats. Some people drink coffee containing MCT oil, ghee, coconut oil, or butter during their fast. Oil breaks a fast, but it won’t break ketosis and can tide you over between meals.
  • Bone broth. This rich source of nutrients can help replenish electrolytes lost during long periods of only drinking water.

Remember that foods and drinks containing any calories — like bone broth and the healthy fats listed above — will technically break your fast.

However, small amounts of these low-carb, high-fat, moderate-protein foods won’t throw your body out of ketosis (13).

SUMMARY

Some people choose to consume small amounts of certain foods and beverages while fasting, such as bone broth or healthy fats. Others consume calorie-free beverages.

Becoming deficient in nutrients while fasting is unlikely, but it depends on how restrictive your fast is and how long it lasts.

Some people choose to take supplements while fasting to ensure adequate vitamin and mineral intake. Fasting too frequently could lead to nutrient deficiencies if your diet is already low in vitamins and minerals (14).

If you supplement while fasting, it’s important to know which supplements could break your fast. This will help you decide if you should take them with a meal or during your fasting period.

Supplements more likely to break a fast

  • Gummy multivitamins. These commonly contain small amounts of sugar, protein, and sometimes fat, which could break your fast.
  • Branched-chain amino acids (BCAAs). BCAAs appear to trigger an insulin response that opposes autophagy (15).
  • Protein powder. Protein powder contains calories and triggers an insulin response, telling your body that you’re not fasting (16).
  • Those containing certain ingredients. Supplements that contain ingredients like maltodextrin, pectin, cane sugar, or fruit juice concentrate contain sugar and calories that could break your fast.

Supplements less likely to break a fast

  • Multivitamins. Brands that don’t contain sugar or added fillers should contain few or no calories.
  • Fish or algae oil. In regular doses, these supplements contain few calories and no digestible carbs.
  • Individual micronutrients. This includes supplements like potassium, vitamin D, or B vitamins (although fat-soluble vitamins A, D, E, and K will be best absorbed when taken with food) (17).
  • Creatine. Creatine is calorie-free and does not affect insulin response (18).
  • Pure collagen. This may slightly impair autophagy but shouldn’t significantly affect ketosis or fat burning during a fast (19).
  • Probiotics and prebiotics. These typically contain no calories or digestible carbs (20).
SUMMARY

Supplements may be used during fasting periods, although some may be better absorbed with food. Supplements that contain calories or sugar are more likely to break your fast.

To break your fast, start by eating gentle foods and be sure not to overeat.

Gentle foods to break a fast

When you’re ready to break your fast, it’s best to ease out of it. Toward the end of your fast, you might want to introduce small portions of foods that are more easily digested, so you don’t overwhelm your digestive system.

Breaking your fast with foods that are especially high in fat, sugar, or even fiber can be difficult for your body to digest, leading to bloating and discomfort.

Foods and drinks that can be even more shocking to your system after a fast include those like a greasy cheeseburger, slice of cake, or soda. Even high-fiber raw produce, nuts, and seeds may be difficult to digest.

On the other hand, nutrient-dense foods that easy to digest and contain a bit of protein and some healthy fats can break your fast more gently.

Below are a few examples of what to eat to break your fast.

  • Smoothies. Blended drinks can be a gentler way to introduce nutrients to your body since they contain less fiber than whole, raw fruits and vegetables.
  • Dried fruits. Dates are a concentrated source of nutrients frequently used to break fasts in Saudi Arabia. Apricots and raisins may have similar effects (21).
  • Soups. Soups that contain protein and easily digestible carbs, such as lentils, tofu, or pasta, can gently break a fast. Avoid soups made with heavy cream or a large amount of high-fiber, raw vegetables.
  • Vegetables. Cooked, soft, starchy vegetables like potatoes can be good food options when breaking a fast.
  • Fermented foods. Try unsweetened yogurt or kefir.
  • Healthy fats. Foods like eggs or avocados can be great first foods to eat after a fast.

Breaking your fast with healthy foods that may be better tolerated can help replenish important nutrients and electrolytes while easing food back into your diet.

Once you’re tolerating gentler foods, add in other healthy foods — like whole grains, beans, vegetables, nuts, seeds, meat, poultry, and fish — and return to eating normally.

Be mindful not to overeat

It can be easy to overeat between fasting periods.

Although fasting doesn’t emphasize what you eat as much as when you eat, it’s not designed to be an excuse to eat unhealthy foods.

Overeating and eating junk food between fasting periods can cancel out the health benefits of fasting. Instead, choose minimally processed, whole foods as much as possible for the most overall health benefits.

SUMMARY

When you’re ready to break your fast, start with foods and drinks that will be gentle on your digestive system. Avoid foods that are especially high in sugar, fat, and fiber. Additionally, take care not to overeat.

When fasting, it’s important to be aware of which foods and supplements may break your fast. You can then decide whether to consume them during or between fasting periods.

During a fast, choose calorie-free beverages and supplements, if any.

Some people choose to eat small amounts of certain foods to curb cravings, which may break your fast but still keep you in ketosis.

When you’re ready to break a fast, focus on easily tolerated foods that don’t contain high amounts of sugar, fat, fiber, or complex carbs that could be difficult to digest.

You can then ease back into a normal, healthy eating pattern.