I think it depends on WHY you got fat. It seems to me that there are mostly two distinct groups, the answer is totally different depending which a person is in, and also each group finds the other one real fuckin annoying when they go talking about whether or not it's possible to go off and stay not fat.
If you got fat because you genuinely didn't understand calorie density, normal exercise, normal portion sizes, and healthy adult foods like vegetables, lean meats, easy on the high fat dairy, sugar, and processed foods, and didn't know that adults usually have to dedicate separate effort to exercise to stay fit, and you have since changed out how you eat and your relationship with exercise and learned how much food you need per day and this is not a problem..then no, there's a fair chance you WON'T regain. Because you didn't actually have issues with food/eating in the first place, you had a lack of knowledge and the shitty standard American diet (or another country's shitty diet standard). GLP-1s can help with that, but they're not really needed to treat that.
If you got fat because even though you DID understand all that, you KNEW how much of what you needed to eat to be not be fat, and you struggled and white knuckled and were hungry, resentful, and miserable and even when you DID manage to get a hold of yourself and lay off the too-much or too-calorie-dense or both for awhile, you always, ALWAYS eventually relapsed....then yes, you probably DO need to be on the meds for life, because you DO have a problem with food/eating and these meds ease that so you don't relapse.
Members of these two groups talking to each other about "how it is" tend to piss each other right off, because they're not the same and they don't seem to notice that there ARE two different major cause groups going on here.
