It isn't just a question of shifting the weight. It is more a question of shifting the fat deposits round the liver and pancreas. Thin people can still have these fat deposits, which are not noticeable from the outside, they are normally detected by scans. Fat people may or may not have these fat deposits.
On a personal level, I shifted all my excess weight, over a third of my starting weight, dropping my BMI from 31 to 21. I have remained at 21 for the past 18 months or so. My diabetes has not disappeared. I return normal BS levels as long as I stick to my low carb diet (under 30g a day) If I exceed this, which I do some days because I'm human, my levels go up accordingly. If I continued to exceed 30g. I would be back where I started in no time. Yes, I could do strenuous exercise to burn off those extra carbs, but that is not a sustainable option for me (and for most other people). Low carb, however, is sustainable providing I consume sufficient fat and protein.