Does breath mints (sugar-free) break a fast?

One small sugar-free breath mint weighs about 0.2 g and has about 0.5 to 1 kcal, with 0 g of sugar. Food labelling counts sugar alcohols at 2.4 kcal per gram, so a 0.2 g mint made mostly of sorbitol comes to about 0.5 kcal. Many sugar-free mints are sweetened with sorbitol or xylitol, often with sucralose as well. Mints made with sugar are a different item, and the sugar breaks a blood-sugar fast.

This site sorts answers by four goals. A sugar-free mint has no sugar, but the site still marks every sweetener grey for a blood-sugar fast, so a sugar-free mint is grey there. For weight loss it is a grey area. The calories are close to zero, but the mint is a sweet taste. Some people find sweet tastes make them hungrier, though the research on this is mixed. Autophagy is grey, as for the other non-caloric sweet tastes in the database. Gut rest is grey because you swallow the sweeteners as the mint dissolves.

The amount changes the answer for your gut. Sorbitol and xylitol can have a laxative effect in large amounts. US rules require a warning on foods that may supply 50 g of sorbitol a day. One or two mints are a tiny dose. A whole tin over a fasting day is a bigger one, so count mints together with any sugar-free gum.

If your mouth feels stale during a fast, brushing your teeth, a mouthwash you spit out and plain water add almost nothing to swallow. Xylitol mints are poisonous to dogs, so keep the tin out of a dog's reach.