For myself, I have no ‘rules’ about food consciously - I only eat when I’m hungry and then I eat as much as I like of what I like.
But
I eat relatively healthily because I don’t crave a lot of processed food and if I buy it someone else will nearly always have eaten it before I get there! I could eat more fruit, and probably ought to up the veg a bit more but otherwise my default choices are not terrible.
If I put my week’s diet down on a weight loss board or whatever I fully expect it would get picked apart for fats/carbs/protein/lean meat etc and I’d feel demoralised. But as I don’t need to change my diet for weight loss purposes I’ve no need to analyse it too much.
Once you’ve let weight creep on it’s much, much harder and I really sympathise with people trying to lose it. If you like fizzy drinks, crisps, chocolate, burgers and chips you have a harder time than if you just don’t naturally choose those foods in the first place.
I was brought up with really good home cooking, nothing restricted but equally treats not bought in regularly. It was an unremarkable food environment, I guess - mum didn’t “diet” but didn’t serve herself the potatoes if she was watching her weight, but it wasn’t obvious. Dad loves to cook so we had good food of all cuisines but sausage, egg & chips was among them. Biscuits were in the house along with fruit but not chocolate on the regular. Squash not fizzy drinks - they were for occasions. We can all cook and did so from teens.
My DH is overweight and struggles. He makes poor food choices, or gets weirdly obsessive about what he ‘can’t’ eat with little basis in any rationale I can fathom. He craves much more processed stuff. His food environment growing up was his mum cooked a 2-week rota of plain food, shopping was strictly rationed, but treats every week without fail - there was the ‘regular’ Tesco shop and the ‘treats’ shop on a Friday for fizzy drinks, desserts etc. His dad was weight-and-fitness obsessed whereas his mum struggled with her weight and has a very sweet tooth. I guess it made it feast-or-famine in some way.
It’s easy not to have ‘rules’ if you’re brought up with the right rules but with no pressure. But that’s hard to do - and terrifically hard to undo if you weren’t.
I try hard not to judge people over food choices.