What breaks a fast

Plain black coffee does not break a fast for weight loss or ketosis. It contains roughly 2 to 5 calories per cup and doe…

Coffee with milk breaks a fast. Milk contains carbohydrate and protein, and dairy protein raises insulin more than its c…

Plain decaf coffee does not break a fast for weight loss, ketosis or autophagy. It behaves like black coffee minus the c…

Plain brewed green tea does not break a fast. It is effectively calorie-free and, if anything, meta-analyses of randomis…

Plain black tea does not break a fast. It contains under 3 calories per cup and does not meaningfully raise insulin. Mil…

Water does not break a fast under any definition. It contains no calories, no macronutrients and does not raise insulin.…

A squeeze of lemon in water does not break a fast for weight loss, ketosis or autophagy. A wedge contributes roughly 1 t…

Plain sparkling water does not break a fast. Carbonated water is water with dissolved carbon dioxide and contains no cal…

Diet soda probably does not break a fast for weight loss or ketosis: it contains no calories and no carbohydrate. Whethe…

Bone broth breaks a fast. It contains protein, typically 6 to 10 g per cup, and protein is the one macronutrient that en…

Milk breaks a fast. It contains carbohydrate, protein and fat, and dairy raises insulin considerably more than its carbo…

Coconut water breaks a fast. It contains roughly 9 grams of sugar and 45 calories per cup, which is real carbohydrate in…

Regular energy drinks break a fast: roughly 27 g of sugar and 110 calories per can. Sugar-free versions probably do not,…

Alcohol breaks a fast. Ethanol supplies 7 calories per gram and is metabolised in preference to everything else. More im…

Pure creatine monohydrate does not break a fast. It contains no calories and does not raise insulin. Flavoured blends, c…

Unflavoured, unsweetened electrolytes (sodium, potassium and magnesium) do not break a fast. They contain no calories an…

LMNT does not break a fast. It contains no sugar, no calories to speak of and no protein, so neither of the mechanisms t…

Salt does not break a fast. Sodium chloride contains no calories and does not raise insulin. On fasts longer than about …

A plain multivitamin tablet does not meaningfully break a fast. The vitamins themselves contain negligible energy. Gummy…

Vitamin D does not break a fast. The dose is measured in micrograms and supplies no meaningful energy, even in an oil-ba…

Fish oil technically breaks a fast, but barely. A 1 gram capsule is pure fat at roughly 9 calories. It contains no prote…

MCT oil breaks a fast on calories, roughly 115 per tablespoon, but it does not raise insulin and it actively raises keto…

Whey protein breaks a fast under every definition. It supplies amino acids, it raises insulin substantially (a whey pre-…

BCAAs break a fast, and they break the autophagy fast most specifically of anything on this site. They are marketed as f…

Collagen breaks a fast. It is protein, roughly 10 grams and 40 calories per scoop, and it supplies amino acids that sign…

It depends entirely on the formula, and this is the substance where "check the label" is the whole answer rather than a …

Pure stevia probably does not break a fast. It contains no calories and controlled trials find no meaningful insulin or …

Sucralose is the sweetener with the most reason for caution. It contains no calories, and pooled trial evidence finds no…

Aspartame probably does not break a fast. It is technically caloric at 4 calories per gram, but it is used in such small…

Erythritol does not break a fast on metabolic grounds. It is a sugar alcohol that is absorbed in the small intestine and…

Pure monk fruit extract does not break a fast. It is calorie-free and a controlled trial found it did not reproduce the …

Honey breaks a fast. It is roughly 82% sugar, and a teaspoon is about 21 calories and 6 grams of carbohydrate. It raises…

Sugar-free gum does not break a fast for weight loss or ketosis. A stick is roughly 2 to 5 calories, mostly sugar alcoho…

Ibuprofen does not break a fast. A tablet contains no meaningful calories and the coating sugar is a fraction of a gram.…

Nicotine contains no calories and does not break a fast in the energy sense. It is not metabolically neutral, though: ni…

A tablespoon of apple cider vinegar does not meaningfully break a fast. It is roughly 3 calories and under 1 gram of car…

A sprinkle of cinnamon does not meaningfully break a fast. A quarter-teaspoon is about 1.5 calories. Meta-analyses find …

Psyllium husk is a borderline case that most people can treat as fast-compatible. It is almost entirely non-fermentable …

Chia seeds break a fast. They are food: roughly 60 calories, 5 grams of fat and 2 grams of protein per tablespoon. The h…

Olive oil breaks a fast on calories, roughly 120 per tablespoon, but it contains no protein and no carbohydrate, so it d…

Yogurt breaks a fast. It contains protein, carbohydrate and fat, and like all dairy it raises insulin considerably more …