I think it is really important to stay 100%. The diet works by putting you into ketosis (where you are fueling your body using your own fat, not glucose). You are turning your body into a rapid fat burning machine (takes people between 3-7 days to get into it). A side effect is hunger suppression. If you cheat- even a little bit- you are taking yourself out of ketosis and it is like starting from scratch again- and your appetite will explode! Thats what has kept me motivated to stay 100%- I'm not going to jack it all in after 9 weeks for a packet of crisps! You would never get back on it again in the same way if you cheated. I'm an all or nothing dieter, so this suits me. The first 4-5 days were hard, but I haven't really felt hungry for the 90% of the rest of the time. And when I have wanted to eat it has been for emotional reasons. It's taught me alot of how I used food before.