Apart from the protein you be taking in a minimum of 1200 calories. If you go below that for any period of time (which you would have while on the pre-op plan) your body will go into starvation mode. Meaning that your body will start to hold on to every calorie to take in. So you will need to increase it. Even if it means drinking 3 instant breakfasts with a scoops of protein powder in every day for awhile. If you dont get enough protein, then could put yourself at risk for hair loss and brittle nails.