One thing I learned is that exercise is at best 20% of what controls our weight. Yes, it had many good effects on us, but losing weight is really a minor one based upon what I have read. It's what we eat that drives weight gain/loss.
I lost 25 pounds and kept it off without going hungry thanks to eating like the book below recommends. I was not severely over weight, but I was going in the wrong direction adding 2 inches to my waist every 2-3 years, with no end in sight. First I gave up the sugar (very hard for me) and lost 10 pounds in a few months. Then, I cut the processed carbs and lost another 15 pounds. My waistline is back to where it was 15 years ago.
Always Hungry by David Ludwig
(Bad title name, IMHO, since the whole idea of the book is to lose weight and not be hungry).
https://www.barnesandnoble.com/w/always-hungry-david-ludwig/1121710248?ean=9781455533879#/
Most libraries have it.
You can watch him explain his studies here:
I can't say it will work for anybody else, but it certainly has for me.