And there are lots of reasons why different things work for different people - its not just their metabolisms but their ability and motivation to stick to a diet, the sort of diet they choose (as some better for quick weight loss than others) and the nature of their exercise regime.
Also on that point - some diets good for fast weight loss but might not be great for keeping weight off longer term. I wanted fast weight loss, and then I'll work at maintenance afterwards.
For me the exercise is about toning and not about loosing weight - I agree weight loss is mainly about what you eat.
Undertone - I have really pushed myself on my exercise regime - admitedly only 3x a week but it has changed & advanced as I have got fitter. Same with the diet - started off on tesco diet totals plan, when I reached a plateau moved to lower carbs... (not ketosis diet though, like dairy too much - basically dukan but have vegetables every day) so have not done anything stupid like maple syrup diet.
Meanwhile, 6 months later...
On 6th October I was 12 5 with 40% fat, size 16 and flabby...
On 6th April I am 9 3 with 24% fat, size 10 and toned...
I don't especially want to loose more "weight", but would like to get to 23%.