I lost almost 15 kg (~33 lbs) over the last two months and I didn't even try that hard. I never had problems with my weight, but over the last few years it slowly crept up to ~107kg (at ~1.95cm), at which point I realised I had to do something. Reasonably sure I could do a The Machinist Christian Bale if I wanted to.

I also quit smoking with relatively little effort twice (once in my early 20s, and then again a few years ago after I picked up smoking again during COVID). It wasn't easy-easy, but if I hear the struggles some other people go through, it was relatively easy.

Some people are just wired different. I have plenty of other issues, but on this sort of thing, for whatever reason I seem to be lucky.