Actually, I stayed away from baking powder in Stage 1. You have to *very* careful with labels – many add corn starch. Beyond that, though, baking powder is basically a blend of baking soda (which is fine on the diet) and cream of tartar. Some cream of tartar is derived from fermentation, and I’ve read, some specifically from yeast. I didn’t want to mess with it. I adapted recipes though, sometimes addinga little more (organic) egg, sometimes trying to add some baking soda and a little lemon or lime (the baking soda works with the acid to make the food fluffy). I also experimented with unbuffered vitamin C powder mixed with the baking soda. About 4 parts baking soda to one part vit C and then that mixture is used as a 1:1 subtitute for baking powder. It works okay, but if your recipe calls for a lot of baking pwder, lots of baking soda can give it a nasty taste. Bitter. I think others have done all right w/ the baking powder, but those are my reasons for staying away from it for the first part. Actually, I didn’t reintroduce it until over 3 months in, and then only ocassionally. There’s a store bought millet bread I can buy that has baking powder.
Anyway, hope this helps some 🙂