Are you wondering what a "clean fast " is? I drink only black coffee, water, unflavored seltzer, and unflavored black or green tea. Here is a great explanation of what can be included in a "clean fast". Gin Stevens is the author of "Delay, Don't Deny": Living an Intermittent Lifestyle". This should be your handbook for IF-its mine!
http://www.ginstephens.com/all-blog-posts/category/clean-fast?
http://www.ginstephens.com/all-blog-posts/category/clean-fast?