I had to do a 6 month weight loss program before my surgery, I gave up sweets, drank mainly water, and because I was insulin resistant, went on a medication called Wegovy. I lost 80 pounds pre surgery. But I knew I needed to lose more and I needed the lifestyle to be less of a choice and more a have to. Sugar was my bane - now if I were to eat sugar I risk dumping syndrome which sounds rather unpleasant. My pain was minimal, but I know mileage varies. Best of luck on your journey, whatever way you go.