Recently lost about 170 lbs about 2 years ago, started around June 2022 about 400lbs (6'3" tall) and by the next summer I was down to about 215, I'm currently sitting between 220 and 225 lbs (put on some additional muscle) and I plan on keeping it off. I did this before in my early 20's (I'll be 45 this summer) where I went from 303lbs to 202lbs. I would say it was actually easier this time and I feel like I'm in just about the best shape I have ever been in despite my age. I started with just intermittent fasting, went to keto and then eventually carnivore. It wasn't uncommon to simply eat 1.5 to 2lbs of steak once a day. I'm at a happy weight right now, I had to replace my entire closet as I went from 3xl - 4xl down to a large in my shirts and went from 54" waist down to 36" waist in my pants and plan to keep it that way. I'm back to eating 2x meals a day and I'm a little more flexible with what I eat, but I try to stay decently strict monday thru thursday but I'm not kicking pizza out of bed on a Friday with the family. I eat a lot of eggs, sausage, bacon, ground meat, steaks and that is about it when I'm strict, and only 1-2 meals a day with no snacking. But I'll still eat cake / ice cream on birthdays and holidays etc, or make a bag of popcorn to watch a movie with the family.
In my 20's when I lost 100lbs the first time I wasn't really following a specific diet but I was trying to remove all the snacks and sweets, but I was eating 6x times a day just very small meals and then working out about 1.5 hours a day 6 days a week. This time when I lost 170lbs I didn't really work-out in a strict fashion, I make sure I get 10,000 steps a day (been doing that for almost 5 years now, but didn't help until I changed my diet) and I don't make excuses to move around. I would play outside the kids (just toss the frisbee or football around, ride bikes etc), but I wasn't going to a gym or anything. I did end up picking up some dumbbells so I'll do some curls, pushups, triceps here and there in the living room.
At almost 45 I run faster and farther than I ever have before, I play a basketball with a group of dads every week going pretty hard for about 1.5 to 2 hours, I go on decently long hikes without having to stop. I sleep way better (still use my CPAP out of habit), and just overall feel so much better, just wish I hadn't kept that 400lbs on for as long as I did, but better late than never.
I would say big thing is stay far far away from seed oils, and try your best to eat whole unprocessed foods, if you can't pronounce the ingredient in your food you don't want it in your body.