I enjoy food and I look at it as nutrition. I was "naturally" slim on good habits through youth but do have to manage it more conciously in my 40s.
I CBA fussing with calories. I plan meals from the protein as my starting point, then the veg/ salad and carbs after. Generally. Not all meals are like this. Lazy opportunism can override. But enough meals are planned well enough for overall decent nutrition.
If I want to fuck my day up, starting with something sweet (including cereal) is an excellent way to initiate spending the whole day on a sugar/ carbs rollercoaster.
Start the day with protein and fibre. Complex carbs such as whole oats also take longer to digest and release their energy. Eggs are quick, easy and versatile. DS started today with a cheesy omlette which took me 5 mins to make and will keep a ravenous 12yo going until lunchtime.
My lunchtimes are hit and miss as I might be out on a long run over that time slot. I eat more carbohydrates on or following energy intense days and fewer on more restful days. My appetite tends to balance out over multiple days.
I've always eaten the more "complete" version of foods. Not to any extreme, but I'd go for the seeded, sliced loaf in the supermarket over the white loaf. This is where calories are unhelpful because while the seeded loaf contains more, it also has more fibre and nutrients left in from the seeds and will keep me satisfied for longer making me far less likely to snack later. "Reduced fat/ sugar" items will be bulked up with nutritionless substances, but the hunger will kick in sooner than with the "full" version.
It is better to eat less processed forms of food.
Genuinely healthy, nutritious foods don't brag about it on the packaging.
A salad will satisfy me because it will have a protein source and some fat. A plain salad doesn't have the range of nutrients you need to be satisfied. If I need more carbohydrate, I'll have some.
¾s of the battle is won in the supermarket. I tend to go to Lidl/ Aldi where the range is more limited and better balanced towards food you'd eat for meals. In a larger shop like Sainsbury's or ASDA, I go to less than half the sections and by-pass zones like alcohol that I don't need. I'm rarely bothered enough to make a trip out for a random snack, but if I do, I do.
I am currently trying to lose a half-stone that's built up in recent years, so I'm conciously eating more plants and cutting the carb portion (generally adding more salad in to that space). At one point last week, I really, really wanted something sweet and ended up making a small batch of cupcakes with a basic flour/ eggs/ butter/ sugar recipe. I did it. I enjoyed it. I moved on. The rest of the day went well. The next day was easier. No regrets.
I don't have anything "banned". There are things like artificial sweetners that I avoid because of their side effects. I have to remind myself that some things are disappointing and just aren't as enjoyable as they were in the past (thanks palm oil) but there is no food group that I ban completely. There are things like cake or alcohol that are best consumed sporadically. There is no moral judgement about what I eat, more how does it serve my needs; mostly a physical question with a slight emotional layer.
The value of calories in nutrition is only that they give a vague idea of intake. You have to have a decent idea of your output for that to have context. They don't tell you how nourishing and satisfying a food is and how balanced your diet is overall.
The Zoe podcasts/ youtube videos are good for information about nutrition for health.