During weight loss, ketones (the by-product of fat burning) are excreted through your breath as well as through the urine. Unfortunately, that can cause unpleasant breath for some people who excrete quite a few ketones that way.
We generally suggest that people use sugarless gum or breath spray to combat “keto-breath”. It’s also helpful to keep your mouth moist by sipping water throughout the day. Adding a thin, fresh lemon slice to your water also helps. Some people chew a bit of the lemon rind for the fresh flavor. Parsley is also a natural breath freshener, so you may want to chew a sprig of fresh parsley, when convenient.
An effective treatment is chlorophyll capsules (one brand recommends taking 90-100 mg a day, usually at night).
We generally don’t recommend using sugar- free mints or sugarless candy because many people end up mindlessly consuming more than they realize. In addition, most people forget to account for the carbohydrates and calories contained in the mints or sugarless candy when they calculate their daily intake.
Bad breath can be an unpleasant side effect of being in ketosis during Weight Loss; but look at it this way, you’re having this problem because you’re burning so much fat, and that’s not bad at all!