My gastric sleeve surgery is scheduled for August 25th. I begin my pre-op diet tomorrow which is a high protein low carb diet. I can't drink during a meal or 30 minutes after. No ban on coffee, only carbonated drinks. My liquid diet is for 24 hours before surgery. After reading some of the other posts I think I have it easy. Anyone know why this is? I'm 64 yo, and weigh 240lb at 5'2. I can't wait to meet the new me. I am so happy I found this app. Michele