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). In regular doses, these supplements contain few calories and no digestible carbs. Brands that don’t contain sugar or added fillers should contain few or no calories. Supplements that contain ingredients like maltodextrin, pectin, cane sugar, or fruit juice concentrate contain sugar and calories that could break your fast. Protein powder contains calories and triggers an insulin response, telling your body that you’re not fasting ( 16). BCAAs appear to trigger an insulin response that opposes autophagy ( 15). These commonly contain small amounts of sugar, protein, and sometimes fat, which could break your fast.

This will help you decide if you should take them with a meal or during your fasting period. If you supplement while fasting, it’s important to know which supplements could break your fast. Fasting too frequently could lead to nutrient deficiencies if your diet is already low in vitamins and minerals ( 14). Some people choose to take supplements while fasting to ensure adequate vitamin and mineral intake. Others consume calorie-free beverages.īecoming 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 consume small amounts of certain foods and beverages while fasting, such as bone broth or healthy fats. However, small amounts of these low-carb, high-fat, moderate-protein foods won’t throw your body out of ketosis ( 13). Remember that foods and drinks containing any calories - like bone broth and the healthy fats listed above - will technically break your fast. This rich source of nutrients can help replenish electrolytes lost during long periods of only drinking water. Oil breaks a fast, but it won’t break ketosis and can tide you over between meals. Some people drink coffee containing MCT oil, ghee, coconut oil, or butter during their fast.

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. However, some people find that adding small amounts of milk or fat can curb hunger. These should mostly be consumed without added sugar, milk, or cream. Plain or carbonated water contains no calories and will keep you hydrated during a fast. Some experts say as long as you keep your carbohydrate intake below 50 grams per day during a fast, you can maintain ketosis ( 13).īelow are some foods and beverages you can consume while fasting. However, you may be able to consume some foods and beverages while still preserving the benefits of fasting. It’s often used for health purposes like weight loss and chronic disease prevention, though it’s been used historically for other reasons.īy definition, fasting means refraining from eating food. Intermittent fasting rotates periods of fasting and periods of eating. 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). It also promotes autophagy, the process by which your body rids itself of unneeded, damaged, or harmful cells ( 5, 6, 7, 8). 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).įurthermore, fasting causes insulin levels to decrease. When you fast, your body undergoes a number of metabolic changes. 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. 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. People have practiced periods of fasting throughout history, such as for spiritual, health, or survival reasons ( 1). It emphasizes when you eat rather than what you eat.Įven though it has recently gained mainstream attention, intermittent fasting isn’t new. Intermittent fasting is an eating pattern that alternates periods of eating with periods of either not eating or taking in minimal calories.

Does butter coffee break a fast