Based on my research, and I'm just a schmuck on the internet, the things that seem to work are: (1) not getting fat in the first place by maintaining a healthy

Based on my research, and I'm just a schmuck on the internet, the things that seem to work are: (1) not getting fat in the first place by maintaining a healthy weight through persistent diet and exercise (2) bariatric surgery (3) GLP-1 drugs, although they're very new and (4) fasting, although that would have to be an ongoing thing, and the evidence for this is promising but limited. Re: (1) I'm not being glib, your body has a strong homeostatic drive and once you overcome it to put on the weight, you have to overcome it to lose the weight - and that's far less enjoyable. Unfortunately losing the weight can come with permanent metabolic adaptations that bias you towards regain, and you'll be fighting them for years.