Don't beat your self up if you slip up and cheat. We are all human and are still dealing with emotional issues, stress, etc. We didnt become heavy overnight and our weight is not going to disappear overnite. I thought the pre op diet was hard and I fixed it to work for me. I was not losing weight on the diet they prescribed and I was feeling weak and dizziness and unable to maintain my strength to wrestle with inmates. Instead of the three yogurts I was allowed a day I ate cheese instead, which count my carbs even more and allowed more protein. I also ate more than the cup of salad that was allowed on my diet. I did drink my protein shakes as advised though. When my surgery was over the I talked to the doctor about my decision and the doctor said my liver was the best he had ever seen, and I had lost twelve pounds. (A lady who was on the same floor as me and had surgery the same day only lost six pounds and she never strayed from the diet.) Yes, I think you should follow the doctors orders and try your very best, it is very hard to adjust to at the beginning, however if you do stray try rearranging your diet to fit your bodies needs. Good Luck