What oils are used in fasting for different health goals?

November 28, 2025 •

4 min read

While a strict water fast prohibits all calories, some forms of fasting allow for the consumption of specific oils to help with energy and satiety. Understanding what oils are used in fasting depends heavily on your specific goals, such as weight management or metabolic health.

Quick Summary

Using oils while fasting is a nuanced topic depending on your specific health goals and protocol. Fats like MCT, olive, and coconut oil are popular for intermittent fasting to aid satiety and fat burning without a significant insulin spike, while pure fasts require zero calories.

Key Points

Fat Intake Varies by Fast: The use of oils depends on the fast's goal; strict fasts prohibit them, while intermittent fasting often allows small amounts of pure fats.
MCT Oil for Ketosis: MCT oil is rapidly converted to ketones for energy, making it popular for intermittent fasters and those on a ketogenic diet to boost energy and suppress hunger.
EVOO and Gut Health: Extra virgin olive oil offers metabolic benefits and antioxidants but may pause the gut's cleansing process; it's best consumed at the end of or during the eating window for gut health.
Fats for Satiety: A small amount of pure fat, like olive oil, coconut oil, or ghee, can help manage hunger and provide stable energy during a fast by keeping insulin levels low.
Quality Over Quantity: High-quality, cold-pressed oils are recommended over refined versions, which contain fewer nutrients and potential additives.
Autophagy and Caloric Intake: For fasts centered on autophagy, consuming any calories, even from fats, can signal the body to stop the cellular cleaning process.

The Fasting Philosophy and Oils

Fasting is not a one-size-fits-all approach. Protocols range from time-restricted eating (intermittent fasting) to prolonged water fasts. For those focused on weight loss and metabolic health, the primary goal during the fasting window is to keep insulin levels low. The insulin hormone is triggered by carbohydrates and proteins, signaling the body to store fat. Since pure fats have a minimal impact on insulin, a small intake of certain oils might not negate the fat-burning state of ketosis for those following a less strict plan. However, it is a caloric intake, so it technically breaks the most rigid definitions of a fast.

Popular Oils and Their Role in Fasting

Olive Oil (EVOO)

Extra virgin olive oil is a core component of the Mediterranean diet and is rich in monounsaturated fats, polyphenols, and vitamins. For intermittent fasting, a small amount is often added during eating windows or at the end of a fast to enhance metabolic effects. Some protocols permit a teaspoon or two during the fast, as it won't significantly spike blood sugar, but it may temporarily pause the gut's cleansing process (Migrating Motor Complex). EVOO supports cardiovascular health and provides anti-inflammatory benefits.

MCT Oil (Medium-Chain Triglyceride)

Derived from coconut oil, MCT oil is a highly concentrated source of medium-chain fatty acids. These are absorbed and processed differently than other fats, being rapidly converted into ketones for energy. This makes MCT oil a popular choice for ketogenic dieters and those using intermittent fasting to sustain ketosis. It can provide an energy boost and curb hunger pangs, especially when added to black coffee. Like other oils, it contains calories and will break a strict fast, but its effect on insulin is minimal.

Coconut Oil

As a natural source of MCTs, virgin coconut oil is often used in fasting, especially in parts of the world where it's a staple. However, it contains other fats, so its MCT concentration is lower than pure MCT oil. Its caloric density means it technically breaks a fast, but many use a small amount to boost energy and satiety. It is also used in certain religious fasts, like Navratri, where purity is a priority.

Ghee (Clarified Butter)

For those not following a vegan diet, ghee is a popular option. It is a source of saturated fat and contains beneficial fatty acids and fat-soluble vitamins. Similar to other pure fats, it has a low impact on insulin levels and can be consumed in small amounts during some fasting protocols, like alternate-day fasting. In Hindu tradition, ghee is considered a holy and nourishing substance used during fasting periods.

The Science Behind Oils and Your Fast

Understanding the purpose of your fast dictates whether oils are appropriate. Fats influence cellular processes in ways that other macronutrients do not. Consuming pure fats like EVOO or MCT oil does not cause a significant insulin release, preserving a state of low insulin and enhanced fat-burning. However, for those aiming for deeper cellular cleansing and repair through a process called autophagy, any caloric intake can be counterproductive. The body will prioritize processing the incoming calories, which temporarily halts the internal recycling mechanisms of autophagy. If your goal is strictly gut rest, even small amounts of oil can stimulate the digestive system and interfere with the process known as the Migrating Motor Complex.

Comparison Table: Oils and Fasting Protocols


Oil	Primary Components	Best Used For	Fasting Implications
Extra Virgin Olive Oil	Monounsaturated fats, polyphenols, vitamins E & K	Intermittent fasting, post-fast meals, metabolic health	Minimal insulin impact; can temporarily pause gut's MMC
MCT Oil	Concentrated medium-chain triglycerides	Ketosis, energy boost, appetite suppression during fast	Rapid conversion to ketones; technically breaks fast but minimal insulin effect
Coconut Oil	High in saturated fat, natural source of MCTs	Intermittent fasting, cooking during eating window, traditional fasts	Caloric content breaks strict fasts, but has a minimal insulin effect in small doses
Ghee	Saturated fat, fat-soluble vitamins	Intermittent fasting, traditional fasts, adding satiety	Low insulin impact; caloric content breaks strict fasts
Avocado Oil	Monounsaturated fats, high smoke point	Intermittent fasting, cooking during eating window	Similar to EVOO; minimal insulin impact, breaks strict fasts due to calories

Key Principles for Using Oils While Fasting

Prioritize your fasting goals: For weight loss, small amounts of pure fats like MCT oil can be acceptable. For therapeutic autophagy or deep gut rest, avoid all caloric intake.
Small amounts are crucial: Stick to one teaspoon or tablespoon at most during a fasting window to prevent a significant caloric load.
Choose high-quality, pure oils: Opt for cold-pressed, unrefined options like extra virgin olive oil to maximize beneficial nutrients and avoid additives found in refined oils.
Consider your fasting window: If gut health is a top priority, reserve oil consumption for your eating window to avoid interfering with the cleansing Migrating Motor Complex (MMC).
Listen to your body: Individual tolerance varies. Some people find that any oil disrupts their fast, while others tolerate small amounts without issues.
Use oils to enhance meals post-fast: Incorporating healthy fats into your first meal can aid nutrient absorption and provide satiety without disrupting the fasting period's benefits.

Conclusion

What oils are used in fasting depends entirely on your specific objectives and the type of fast you are undertaking. For many practitioners of intermittent fasting focused on metabolic health, small amounts of high-quality fats like MCT oil, extra virgin olive oil, and ghee can be helpful for sustaining energy and curbing appetite. However, for those observing a strict water-only or religious fast, any caloric oil is prohibited. By understanding your personal goals and the science behind different types of fats, you can make an informed choice. Always prioritize high-quality, cold-pressed oils and consider using them during your eating window, particularly if gut health is a concern. The goal is to use these fats strategically to support your overall health and fasting journey.

For more information on selecting healthy cooking oils, refer to resources like the Cleveland Clinic Health Essentials guide.

Frequently Asked Questions

Technically, yes, because it contains calories. However, for intermittent fasting focused on keeping insulin low, a small amount (1-2 tablespoons) of high-quality EVOO is often permissible as it doesn't cause a significant insulin spike.

Yes, many people use small amounts of coconut oil during intermittent fasting. As a source of MCTs, it can provide quick energy and boost satiety, but its caloric content means it technically breaks a strict fast.

Yes. MCT oil is a concentrated version of the medium-chain triglycerides found in coconut oil. This means it is more efficiently and quickly converted into ketones for energy, making it a more potent tool for sustaining ketosis.

Highly refined or processed oils are generally avoided. For strict fasts aimed at autophagy or gut rest, any oil, regardless of type, should be avoided as it provides calories and activates digestive processes.

If you are following a modified intermittent fasting protocol, a typical recommendation is one to two tablespoons of a pure fat like olive or MCT oil. The amount can depend on your specific goals and tolerance.

The oils permitted in religious fasting vary widely by tradition and specific observances. For example, some Hindu traditions during Navratri use pure, cold-pressed oils like groundnut or coconut oil for cooking, while others may follow stricter rules.

For those practicing intermittent fasting, consuming a small amount of fat, like a teaspoon in coffee, is often done during the fasting window to boost energy. For optimal gut health, however, consuming oils during the eating window is recommended.