No Snacks, no sweets, no seconds. Except on Days that start with S. Too simple for you? Simple is why it works. Look here for questions, introductions, support, success stories.
Only if it's got some sort of sugary based mixer, like a Daquiri or Chocolate Mudslide
But you can have one or two non sugary drinks on N days.. a glass of wine or beer or vodka etc.
