I think it’s easier for those of us who naturally adjust their food intake when we’ve had big/heavy meals and don’t overeat.
I’m naturally slim and the same weight since my teenage years. I’ve never ever thought about my diet. I never consciously monitor or adjust what I’m eating. I never deprive myself. But I do naturally feel like I want a light dinner if I’ve had a big lunch. I don’t like the feeling of being too full. I don’t feel I have to finish everything on my plate.
My DH is a healthy weight but has to work to maintain it - he doesn’t seem to have the same connection between brain and body and will often over eat (eg if we go on holiday he will have big breakfasts at the hotel and then enjoy eating out and will come home having put on weight, whereas I’ve never fluctuated like this).
I eat a healthy diet.
Today for example - breakfast was oats, banana and yogurt
Lunch was a veggie soup with beans for protein
I had a couple of snacks - nuts, fruit and a glass of soya milk
Dinner was brown rice bibimbap with plenty of veggies and protein
I’d also say I’m fairly active, although I have a desk job I have a dog so walk 1-2 hours a day plus run and go to the gym.