Wow, til.

Is there anything they can do about the breath? (ditto people on keto diet)

On a ketogenic[diet] ... your body uses fat instead of carbohydrates for energy. This shift causes a major spike in ketones, the source of acetone breath. ... Sweet-smelling breath may be a short-term side effect of this type of diet.[0]

[0] https://www.webmd.com/diabetes/acetone-breath-diabetes

So low blood sugar causes sweet breath.