Does diet soda break a fast?
Calorie-free, but appetite may change
0-5 kcal
Maybe - use caution. Most diet sodas are near zero calories, but sweet taste can increase cravings for some people.
Most diet sodas are near zero calories, but sweet taste can increase cravings for some people.
Diet sodas are ~0–5 kcal, so they are not a calorie break. The debate is behavioral: sweet taste can drive cravings for some people.
Base tier: 60/100 for "Use caution". Item adjustment: 0 points for calories, nutrient signal, product variability, and safety caution. Final Fast Score: 60/100.
If it makes the fast harder, keep it for the eating window.
The Fast Score is an editorial estimate of clean-fast strictness, not medical advice. Goals vary — if you fast for glucose, appetite, or medical reasons, follow your clinician.