I wouldn't use that terminology of "cleansing" etc. for food. It sounds too wooey. There is evidence that intermittant fasting has benefits but it isn't some magical thing, and I doubt it has anything to do with your stammer. There are some things I can talk about easily, and some things I can't. Your job is something you are probably comfortable explaining, and having confidence is great. I am in a high stress job environment as a teacher, and I can tell you that stress totally makes the talking difficult.