Many patients leave hospital on less medication than they arrived with — before losing significant weight. That is hormonal, not caloric.
Rerouting the intestine changes the secretion of gut hormones such as GLP-1 and GIP within days, improving insulin sensitivity and beta-cell response independently of weight loss. This is why bypass is described as metabolic surgery, not just weight-loss surgery.
Long-term trials report remission of type-2 diabetes in a substantial majority of patients after bypass, with sleeve close behind. Remission means normal glucose without medication — not cure, because it can return.
Shorter duration of diabetes, no insulin use, and preserved beta-cell function predict the strongest response. Someone diagnosed two years ago has a far better chance than someone on insulin for fifteen.
Annual HbA1c, ongoing dietary discipline and awareness that regain can bring diabetes back. Remission is a state to be maintained, not a finish line.
Doses are usually reduced during the hospital stay and adjusted weekly afterwards, always in coordination with your own physician.