What is allowed to be eaten during fasting?

November 3, 2025 •

4 min read

According to a study published in the New England Journal of Medicine, different fasting protocols yield various health benefits, including better brain health and body composition. Knowing what is allowed to be eaten during fasting is key to achieving these benefits without disrupting the process, as the rules differ significantly across various methods, from intermittent to religious fasts.

Quick Summary

Different fasting methods have distinct rules about what can be consumed. While strict fasts permit only zero-calorie fluids, modified approaches may allow small amounts of fats or specific low-carb foods. What is consumed depends on the specific goals, such as weight loss or spiritual observance, and the type of fast being practiced.

Key Points

Understand the Type of Fast: Different fasts (e.g., intermittent, religious, medical) have distinct rules on what you can consume.
Stay Hydrated with Zero-Calorie Drinks: During a strict fast, stick to water, black coffee, and plain tea to avoid breaking the fasted state.
Avoid Calorie-Containing Drinks: Sugary sodas, fruit juices, and milk are not permitted during fasting periods.
Mindful Re-feeding: After a fast, reintroduce food gradually with easily digestible items like broth or fruit to avoid digestive discomfort.
Religious Fasts Have Specific Lists: Observances like the Daniel Fast permit plant-based foods, while others like Navratri have their own grain and food restrictions.
Consult a Doctor for Health Concerns: Individuals with pre-existing health conditions should seek medical advice before fasting.
Listen to Your Body: Pay close attention to your body's signals during a fast and adjust your approach if you feel unwell.

Understanding the Different Types of Fasting

Before determining what is allowed during fasting, it is crucial to understand that fasting is not a one-size-fits-all practice. The rules depend entirely on the type of fast you are observing and your personal goals. For example, a complete water-only fast has entirely different restrictions than intermittent fasting or a religious fast like the Daniel Fast.

Intermittent Fasting (IF) Protocols

Intermittent fasting involves cycling between periods of eating and fasting. For most IF schedules, the fasting window is a strict no-calorie period to promote metabolic switching, where the body shifts from burning sugar to fat for energy.

What is typically allowed?

Water: Plain or carbonated water is essential for hydration and contains zero calories, so it will not break a fast.
Black Coffee: Unsweetened, black coffee is permissible and may even help suppress appetite for some. Avoid sugar, milk, or cream, which add calories and can disrupt the fasted state.
Plain Tea: Herbal or black tea without any additives like sugar, honey, or cream is generally accepted.
Healthy Fats (Modified Fast): Some people practice a modified fast, especially for ketogenic purposes, where small amounts of healthy fats like MCT oil, butter, or coconut oil are added to coffee. While technically adding calories, this approach may not knock the body out of ketosis.

Religious and Spiritual Fasting

Religious fasts often have their own specific, culturally-dictated rules concerning food and drink. These are typically not based on caloric restriction but on spiritual discipline.

Examples of religious fasting foods:

Daniel Fast: This is a partial fast following a strict vegan diet for 10-21 days, avoiding meat, dairy, refined grains, and processed foods. Permitted foods include fruits, vegetables, nuts, seeds, and whole grains.
Navratri Fast (Hinduism): Common in Hinduism, this fast avoids grains like wheat and rice. Followers eat specially permitted foods such as buckwheat (kuttu), sago (sabudana), certain millets, fruits, nuts, and dairy products like paneer and milk.
Ramadan Fast (Islam): During Ramadan, fasting involves abstaining from all food and water from sunrise to sunset. Meals are consumed during the pre-dawn (Suhoor) and post-sunset (Iftar) windows.

Medical and Diagnostic Fasting

In a medical context, fasting rules are strictly followed to ensure accurate test results or safe surgical procedures. For a standard blood test, you may only be allowed to drink water, while for some procedures, nothing at all (absolute fast) may be permitted. Always follow your doctor's precise instructions.

Foods and Drinks That Will Break Your Fast

Understanding what to avoid is just as important as knowing what is allowed. Any food or drink containing calories, especially sugar and protein, will signal your body to exit the fasted state.

Sugary Drinks: Soda, sweetened teas, and fruit juices instantly raise blood sugar and trigger an insulin response.
Processed Foods: Packaged snacks, sweets, and fast food are high in calories and offer minimal nutritional value, completely disrupting a fast.
Protein Powders & Supplements with Calories: Most protein powders contain calories and amino acids that will break a fast. Check labels carefully for hidden calories in supplements.
Dairy: Milk and cream, even in small amounts, contain calories and sugars that will end your fasting period.
Alcohol: Alcoholic beverages contain calories and can interfere with the fasting process and its health benefits.

Comparison of Fasting Methods and Allowed Foods


Feature	Intermittent Fasting (16:8)	Daniel Fast (Religious)	Water-Only Fast	Modified Keto Fast (IF)
Core Purpose	Metabolic health, weight loss	Spiritual discipline, spiritual cleansing	Physical detox, discipline	Metabolic health, ketosis
Allowed Foods	Water, black coffee, plain tea during fasting window. Healthy, balanced meals during eating window.	Fruits, vegetables, nuts, seeds, whole grains, legumes, water, juices.	Only water is permitted for the entire duration.	Water, black coffee, plain tea, small amounts of healthy fats (e.g., MCT oil).
Foods to Avoid	All calorie-containing foods and drinks during fasting window.	All animal products, refined grains, sugar, processed foods, alcohol.	All foods and drinks except water.	All sugary foods, high-carb items, and proteins during the fasting window.
Duration	Varies (e.g., 16 hours fast, 8 hours eat).	Typically 10 to 21 days.	Short term (e.g., 24-72 hours) and should be medically supervised.	Follows an intermittent schedule with minor modifications.

Practical Tips for Successful Fasting

To make your fast effective and manageable, especially if you are new to the practice, consider these practical tips:

Listen to Your Body: Pay attention to how you feel. If you feel dizzy, overly weak, or experience other adverse symptoms, it might be necessary to adjust your fasting duration or diet.
Stay Hydrated: This is the most crucial rule for any type of fasting. Water, mineral water, and unsweetened teas are your best friends. Dehydration is a major risk, especially during extended fasts.
Ease Back Into Eating: When breaking a fast, especially a longer one, start with easily digestible, nutrient-dense foods. Broth, yogurt, or a simple soup can prepare your digestive system for more substantial meals later.
Plan Your Eating Window: If you're on an intermittent or religious fast with a designated eating period, plan your meals to include a balance of carbohydrates, proteins, and healthy fats. This will help you maintain energy and feel satiated.
Consult a Professional: If you have underlying health conditions like diabetes, or if you are pregnant or breastfeeding, it is essential to consult a doctor before beginning any fasting regimen.

Conclusion

Understanding what is allowed to be eaten during fasting depends entirely on the type of fast you are observing. From the zero-calorie rule of strict intermittent fasting to the plant-based protocols of religious observances, the guidelines are specific. While water and unsweetened beverages are universally acceptable during non-eating periods, other items can vary significantly. By following the specific rules for your chosen fast, staying hydrated, and listening to your body's signals, you can perform your fast safely and effectively, achieving your health or spiritual goals.

Frequently Asked Questions

Yes, you can drink black coffee during a fasting period, as it contains very few calories and won't break your fast. However, adding sugar, milk, or cream will add calories and disrupt the fasted state.

During most fasts, you are allowed to consume zero-calorie liquids such as water (plain or sparkling), unsweetened black coffee, and plain herbal or green tea. Staying hydrated is essential.

Technically, yes, bone broth contains some calories and nutrients, so it will break a strict fast. However, in some modified fasting methods, especially for those seeking to replenish electrolytes, small amounts of bone broth are sometimes consumed.

This depends on the type of fast. In strict intermittent fasting, fruits and vegetables with calories are not allowed during the fasting window. In certain religious fasts, like the Daniel Fast, a plant-based diet of fruits and vegetables is the focus.

Some zero-calorie supplements like individual vitamins (potassium, D, B) and creatine may not break a fast. However, many supplements, especially gummies and protein powders, contain calories and sugar that will end a fast. Always check the label.

After fasting, it is best to break it gently to avoid digestive issues. Start with easily digestible, nutrient-dense foods like broth, smoothies, or soft, cooked vegetables. Avoid consuming large, heavy meals right away.

During a Navratri fast, common grains like wheat and rice are typically avoided. Forbidden foods also include non-vegetarian items, alcohol, and certain spices like turmeric and mustard seeds.