Oh I cheated with some chicken, tuna and cucumber in the beginning, and I felt so guilty that I buckled down and punished myself. My program was shakes and allowed additives like fruit, oatmeal, peanut butter, skim milk, ect. I literally mixed the powder with plain water for the last week of my pre op diet. No doubt I was in ketosis and I ended up loosing 27lbs in that 2 weeks, 20lbs of which was the last week.