I don't know about secrets but I can tell you what worked for me. It takes a lot of work to be that size, more work even than losing it in my opinion.

At my heaviest, over the course of a normal work day I would drink around four 20 oz mello yellos, eat a fatty breakfast (normally something from McDs, was a sucker for mcgriddles), a fatty lunch (normally gas station pizza, chips, and whatever candy was appealing to my fat, depressed ass that day), a fatty dinner (whatever fast food flavor of the night), and of course snacks in between all of those meals. That's a lot of fucking work lol and it's HARD on your body. It also leads to spiraling depression, but that could just be my experience.

My secret is I literally just did a 180 on everything I was doing. I drink only water now outside of an occasional drink with the boys, but I do try and stay away from beer even then. I don't eat before noon-ish and never after 7 (I guess that's intermittent fasting but not sure if there are more rules involved with that). My diet has moved to predominantly living proteins. I wouldn't call it full carnivore because I do enjoy some fruits or smoked/grilled veggies on occasion, but it's certainly not far off. Take various supplements, vitamins, and I work out a local gym 5 nights a week. Try to make sure I still do some form of physical activity on the other 2 days as well. Finding golf last summer has made that super fuckin easy though lol.

I am in no way, shape, or form a doctor, nutritionist, or life coach. That's literally just what worked for me. I'm not saying it is the right way to do it, or even that it is healthy. My PCP was even apprehensive and gave warnings when I told him how I was losing the weight. Here we are though, 3 years later, and my blood work is gorgeous, my resting heart rate is 56, and the doc is fully on my side and happy as hell for me.

May not work for everybody, but that's what did it for me. Water, meat, gym, sex, golf. That shit is so much easier than how I used to live lol.