I don’t think you have to maintain some idea that all food is equal; it’s ok (and helpful) to acknowledge that different types of food are different from one another without labelling them as good or bad.
The idea that food is good or bad can result in feelings of shame or anxiety around food. It can lead kids into unhealthy patterns of restriction or, alternatively, it can make ‘bad’ foods something that children obsess over on the basis that they’re overly restricted.
In our household we talk factually about what different foods do for our bodies, without labelling them as good or bad. So I’ll tell my 4yo son that chocolate tastes good and gives us a short burst of energy that we use up quickly, whereas something like eggs and avocado on toast tastes good, gives us energy, makes our bodies strong and gives us vitamins that stop us getting sick.
I tell him it’s important to eat all kinds of foods because all foods do different jobs. So we get to eat chocolate for tastiness and for quick energy, and we get to eat eggs and avocado on toast for tastiness, slow energy, making our bodies strong and getting vitamins.
I present food like chocolate / desserts etc alongside his main meals. I control portions. So tonight I set out his main meal (cheese and tomato pasta, grilled tomatoes and peas) with two little chocolate eggs. He asked for more chocolate when he was done and I said there isn’t any more chocolate just now. It’s ok to portion out foods you want to limit, and you don’t have to say it’s because they’re bad or unhealthy.