@jime51 Losing fat takes stress off of the capacity constraints that keep pre& diabetics from clearing glucose from the bloodstream in a rapid fashion. However, it does not increase the capacity. Losing 40 pounds should have lowered your A1c to normal levels. With regained weight that stress has returned and the capacity is probably lower than it was 5 years ago so you should do something.

On any diet it is use it or lose it. Resistance exercise is required to maintain muscle and increase the percentage of fat lost. There is nothing different when you end a diet either from Weight Watchers or using GLP-1s. If you go back to your pre-diet norms you will regain the weight. The problem is that to lose the weight on a normal diet probably took some changes in habits that will continue after the diet ends. GLP-1s suppress hunger signals that will return when they are discontinued. On a normal diet you probably gain some resistance to those signals. When I lost 40 pounds on a classic diet, I was hungry all of the time. That is the big difference with GLP-1s. You lose the weight but are not hungry. If you quit GLP-1s you have to have a lot of discipline to resist hunger signals and not go back to the habits that caused the weight gain. There is nothing magical that makes people regain weight lost on GLP-1 drugs. It is more that it was so easy losing the weight they do not realize the hard part in any diet is going to be keeping it off long term.

GLP-1s are natural hormones that your body produces. The drug versions are resistant to the DPP4 enzyme so are long acting. DPP4 destroys natural GLP-1 in 1-2 minutes so not the same hunger suppression. Before GLP-1s, the ...gliptins were developed to suppress DPP4, extending natural GLP-1 life and lowering blood glucose.