Food, exercise, sleep, age: they're all variables which affect weight loss and maintenance.
As Meg sometimes says, we are all an experiment of one. This may affect me but not you. That may affect you but not me.
I think I'd recommend you just keep a weather eye on all the variables as you get older. See how your particular case is affected (or not). And how you feel. I don't feel like eating as much now as I did 20 or 30 years ago. And as a parallel, I'll just mention all the stuff that's written about the peri-menopause and menopause (Doom! Heat! Moods!). Fingers crossed, none of that has happened to me yet and I'm 55. Actually, I'm much less moody.
Some might say I'm quite cheerful.