It helps if you have a very, very strong VISCERAL, smack you across the face reason to get back in shape and eat better + it’s also a heck of a lot easier to mostly eat fairly healthy stuff, avoid excessive binge drinking etc if you are happy and have a well thought out plan with quantifiable goals.
To give you a lil idea about how I did it and am still doing it, 3.5 months ago I came off anti-psychotics & the day after that I weighed in at a whopping 350lbs (I’m 6ft & 6 and have been lifting weights for about 20 years, but still, that was too much weight gain to accept). I weighed about 290lbs before I started taking AP’s about 6 years ago
So what did I do? I made a plan, my plan consisted of drinking no more than about 21 UK units of alcohol per week (when I was on anti-psychotics) I’d routinely get through as much of over a litre of spirits a night, up to a few nights a week, I got so efficient at boozing, working my way through a 70cl bottle of whiskey or vodka + a bit extra never even got me close to a hangover the next day. I also started drinking at least 2 litres of water a day (more like 3 if it was hot), I limited myself to one takeway meal per fortnight, one dessert a week and the rest was just hard, consistent training, plenty of veggies, lots of leanish protein, stuff like lentil soup + a lil meat, tuna with half pasta and half cous cous etc fills you up and delivers plenty of protein reasonable amount of carbs.