Will Diet Soda Break a Fast?

Diet soda. Diet soda contains neither calories nor any compounds with measurable effects on insulin. It won't break a fast, but that doesn't mean I'm a fan. Try putting a no-sugar drink mix like LMNT in some sparkling water.

Can you drink zero calorie drinks while fasting?

Drinking moderate amounts of very low- or zero-calorie beverages during a fasting window is unlikely to compromise your fast in any significant way. This includes drinks like black coffee.

Can you drink diet drinks while intermittent fasting?

Drinks with calories higher than single digits can break your fast and undo your effort. Even some non-caloric drinks, such as diet sodas, flavored waters, or anything containing artificial sweeteners, can provoke the insulin response and interfere with your fast.