I understand what you mean about disordered eating and the hold it takes on your life. I'm around a size 8-10 normally, currently more like a 12 as I'm pregnant. I have no idea honestly if I'm "naturally slim" or not. My father is vast, my mother is tiny. I was overweight as a young teen then suffered quite a severe eating disorder and went down to a size 6 at most. I'm now 30 and have been a healthy weight for about 10 years. For me maintaining a healthy relationship with food (neither over nor under eating, and not thinking about food 24/7) relies quite heavily on not doing anything like calorie counting or weighing myself. I don't own a set of scales, I don't look at the nutritional info on food. I let myself be weighed at my booking appointment for my pregnancy, but that's literally the only time I've been weighed in 10 years. Like how an ex smoker can't just have 1 cigarette. Sometimes my clothes feel a little tight, sometimes a little loose, and then I just concentrate on making no changes to my diet or exercise and it always self regulates back to my clothes fitting normally. For me there is no quicker way to lose control of my weight than to make active attempts to regulate it. Not thinking about it at all is the best way for me to maintain a healthy weight. Which I appreciate sounds a bit contradictory since I'm posting on this thread! Anyway, my daily meals look a bit like this:
Breakfast: cereal (usually musli) with almond or oat milk
Lunch: almost always cheese sandwiches, usually 2. Real butter, sometimes mayo and salad. I bloody love cheese and would probably eat it 24/7 if I could.
Dinner: something vegetarian and home cooked - stir fry, pasta, chilli, cauliflower cheese, Quorn or soya something (like quorn sausage and mash).
I don't weigh or measure portions, or go out of my way to use low fat ingredients like that low calorie cooking spray etc, as for me this counts as "thinking too much about the food". I eat butter because I like butter over marj, I prefer almond milk over cows milk, it's not about one being higher or lower fat. I don't go to the gym or do any structured exercise, but I am on my feet most of the day chasing my toddler. I rarely drive/ use public transport and consider anything up to an hour away to be walking distance. I've always had active jobs as well, working in schools or hospitals.
Taking steps to not think about my food intake or weight too much has broken the hold disordered eating had on my life. I can eat until I'm full and then stop, even if there's still food on the plate. I can have a packet of biscuits open beside me and only eat 1. I bought my favourite crisps and dip last week and still haven't opened them as I keep forgetting they're there. Getting to this point has helped me maintain a healthy weight more than planning, dieting, and having weight goals ever did. Of course it's different for everyone, but for me the key was to take back control. Like they say with relationships "whoever cares the least has the power". I love good food and enjoy cooking new dishes/ going to restaurants, but I don't care about my weight and my food and the relationship between them in the way that I used to. In my relationship with food now, I have the power.