For me at least it definitely wasn't quite so abrupt, it was probably about 2.5 months before I noticed the trend line ever so slowly moving up. Pre-Zepbound I had already lost about 30 pounds from my max weight of 260ish thanks to a strict Keto diet I began at the beginning of COVID lockdowns which was a lot of effort to maintain long term, so when I saw I met the criteria for my insurance to cover Zepbound I was like "sure, why not?".

I'd probably just go back to Keto if I decided or was forced to stop a GLP-1a completely. Keto was the first and only way I've had success losing weight in my life. But once the initial novelty wears off it takes a lot of discipline to stick to and continually avoid the pressure from friends/family to eat with everyone else. I'm also vaguely concerned about cholesterol impact long term doing it for life, but relative to obesity probably still a good trade off.

It's definitely doable though, I did it for 2 years so I know the drill and that's my fallback. But not being obese is much more enjoyable than being obese, and it's a lot easier to exercise at a normal weight, so I don't have much interest in going back to 260 pounds. If that meant taking a drug for life, so be it unless it turns out to cause turbo-cancer or something.

I mostly eat "healthy" foods by preference (and habit from growing up in a "health food" family), but for me my problem is managing portion control while never feeling completely full at the target calories per meal/day. Which can feel pretty miserable to stick with especially comparing to others in my family who more or less eat the same foods but don't have that problem at all. Keto was so effective because I actually felt "full" (at the expense of excluding a lot of otherwise healthy but carb-rich foods).

Taking Zepbound definitely reshaped my perception of obesity though, compared to Keto which required constant, intense self-enforced discipline avoiding 4/5 of any menu, being on a GLP1-a and able to eat what everyone else is eating but just stop and not feel hunger pains or cravings convinced me the attitude of "fat=lacking discipline" is antiquated and ignores real variance in how different people experience hunger/satiation.