Having previously been grossly overweight for most of my life, I finally turned things around approx 15 years ago and have so far lost over 10 stones. I was in denial and blamed "big bones", "metabolism", etc.
But the reality of it is that I ate too much and moved too little.
"Eat less and move more" really can help the vast majority of overweight people.
But it takes time, as I say, in my case, 15 years and counting.
I make sure I am active, most of the day, every day. That may mean using a standing desk if I know I'm going to be stuck in my office most of the day (bad weather etc), or making sure I go for 2 or 3 walks a day if I can, or using a treadmill for walking in my garage when I'm home on wet weekends etc.
Alongside that, being realistic about the type and quantity of food I eat, i.e. being aware of what contains sugars, fats, carbs, etc., and reducing the quantity of those, whilst increasing quantities of fruit and veg and lean meats. I can, and do, eat the occasional chocolate bar, bag of crisps, even the occasional McDonalds, but it's all in moderation and balanced - if I have something high in calories, then I balance it out at a different meal that day with something very low in calories. I'd never have McDonalds for lunch and fish & chips for tea, for example. A bit of advance planning goes a long way, i.e. if you know you're having McDonalds for lunch, then have a light breakfast beforehand and a light evening meal afterwards.
I've also got into the habit of avoiding buying larger portions or multi-buys "just because" they seem cheaper, i.e. a bigger bag of crisps in a meal deal or a 4 pack of kit kats - I just ended up eating more, and at the height of my food addiction, rather than a single kit kat, I'd buy a 4-pack multipack and eat them all in one go. Now I buy a single kit kat and eat it on it's own!
I've managed to reverse T2 diabetes, which is something I'd been diagnosed with over 30 years ago! Cutting out excess carbs and sugar from my diet caused my blood sugar levels to come back within normal ranges, even after decades of abuse.