Your pre-op diet is as important as your post-op diet. What type of surgery are you having?
For the gastric bypass and the gastric sleeve, you should be on a liquid diet for one to two weeks before surgery. The liquid diet helps reduce the amount of fat that’s present around the liver and spleen, which makes it easier for your surgeon to visualize your digestive organs.
You should consult with your surgeon, of course, but for most bariatric surgeries, you should be on a liquid diet one to two weeks prior to your surgery. You may be allowed to have protein shakes or meal replacement shakes and sugar-free beverages. Your surgeon may okay eating lean meats and vegetables as well.