Its quite common to experience "bad breath" and/or "constipation" during the LCHF transition phase (approximately first 3 weeks). Here are some remedies that may be of assistance.

1. Bad Breath
Chew on mint leaves and/or gargle with a mixture of baking soda and lukewarm water. (About 1 tsp baking soda to half a glass of lukewarm water)

2. Constipation
Eat plenty of green leafy vegetables; drink lots of water; have at least 1 tbsp of of organic coconut oil in the morning (can be stirred into coffee or eaten just like that).
3. If you have any other suggestions, please feel free to share

Always do your best. What you plant now, you will harvest later.
(Og Mandino)