> In the end someone else cooks for you and packages it.

I think someone else cooking for you isn't the problem, the problem is at "packages it". Because, when you cook something at home, it's good for a few days to a week -- but food processors effectively always need various additives to keep the food shelf-stable for long enough for it to go factory -> warehouse -> store -> your house -> your meal. There are definitely exceptions (eg raisins are dried grapes, end of story) but generally this is the problem.

> Whole grain bread... very healthy.

Are you sure? Ever noticed how when you bake bread at home, it's basically 4 days on the counter before it's inedible, right? Yet commercial bread lasts for weeks.. ever wondered why that is?

As for processed food in general, I could be wrong, but my mental exercise goes along the lines of "would my great-grandma know what this is?" Eggs, butter, milk, fruits, vegetables, flour, rice, meat, fish, etc etc. But if it has an ingredients list and a nutrition label.. probably best to avoid making it a staple of your diet. Yes, I get it, cooking is a pain in the ass and everyone hates "the dinner problem", but IMO it's worth it for your health.