Does olive oil break ketosis?

No, it is pure fat and supports ketosis.

Can a spoon of olive oil curb hunger while fasting?

It can, but it breaks a strict fast since it provides calories.

Does olive oil raise insulin?

No, fat does not meaningfully raise insulin.

Does Olive Oil Break a Fast?

Reviewed by the FastTrack team · Updated June 2026

Short answer: Yes

Olive oil breaks a fast. It is pure fat at about 120 calories per tablespoon, so it ends a calorie or autophagy fast, although it does not raise insulin or break ketosis.

Calories	~120 kcal per tbsp
Breaks a weight-loss fast?	Yes
Breaks ketosis?	No
Breaks autophagy?	Yes
Insulin impact	None

Why olive oil breaks a fast

Olive oil is entirely fat, roughly 120 calories per tablespoon, with no carbohydrate or protein. It does not raise insulin or interrupt ketosis, but those calories break a fast defined by calorie restriction and they switch off autophagy. A spoonful of olive oil is food.

Save it for your eating window

Some Mediterranean-style protocols include a spoon of olive oil during a fast for satiety, but strictly that is no longer a fast. For maximum autophagy or calorie restriction, keep olive oil for your meals, where its heart-healthy fats are a genuine benefit.

How much is safe

Even a spoonful adds about 120 calories, so keep olive oil for your eating window if you want the cleanest fast.

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Frequently asked questions

Does olive oil break a fast?: Yes, its calories break a calorie or autophagy fast.
Does olive oil break ketosis?: No, it is pure fat and supports ketosis.
Can a spoon of olive oil curb hunger while fasting?: It can, but it breaks a strict fast since it provides calories.
Does olive oil raise insulin?: No, fat does not meaningfully raise insulin.