I think you instinctively "know" if you are overweight. I've always thought my "fighting weight" was 14.5 st. The medics told me several year back that I ought to be 13.5st, which, frankly, was ridiculous - I'd never been that as an adult. There is no point in setting targets that are unrealistic - well, that's my view.
But it has been creeping up and now I am just under 16st. I know that's too much, and the evidence was when the waitress at the tea-rooms in Castle Cary, Somerset (where we had a couple of days last bank holiday) ushered us to a tight table set in an alcove, and I could hardly fit in the seat ....
So yes, I need to bring it back to 15st or thereabouts. Going to do that crazy melon and cabbage soup diet to get it started, and then try to keep it under check.
The thing that does for me (and Mrs O) is the snacking while watching TV in the evenings ....