CICO as an assumption is important. It certainly doesn't solve obesity, but it makes the problem measurable. For me it is mostly about the amount of sweet stuf

CICO as an assumption is important. It certainly doesn't solve obesity, but it makes the problem measurable. For me it is mostly about the amount of sweet stuff, however in general it is about the appetite/calorie ratio. You can eat "unhealthy" food and still lose weight. My body wants sugar once a week or so, however that's still fine. It's probably obvious, but avoid eating food you don't like, just because it is less calorie/supposedly healthy. This leads to enormous frustration. Experimenting however is a good idea, the more alternatives one has the better.