I've lost 40-60+ pounds several times
the only time I ever kept it off was when I started eating more fats, not less.
You can lose weight on any diet. In my experience you can't keep it off on any diet. Last year was the 1st time I ever kept weight off while hardly doing any exercise and kept my lean muscle mass to the point where the 1st bike ride in over a year was very nearly like the last ride the year before.
(Good) dietary fat is not a problem in and of itself. Omega 6 fats should be avoided as much as possible (good luck if you eat anything even slightly processed) and should be swapped out for Omega 3 when/wherever possible.
Fat and protein are not the problem with weight and the associated medical issues: heart disease, diabetes, alzheimers etc.
I hope you find what you need to do for you and that it works.
I'm tired of my journey and very glad it's over.