I was sleeved on Jan. 7 2013 and my weight stopped as soon as I added protein shakes, which was 1 week after surgery. I drink at least 64oz.of water and get 80 grams of protein per day. I also added walking to my routine. I lost 18lbs on pre-op diet and 14 lbs 1 week after surgery but now the scale has stopped. What gives?