"Why are you eating unhealthy food?"
Translation:Почему ты ешь вредную еду?
In English I feel there's a difference between saying "eating something unhealthy" and "eating something harmful". Does Russian not have that distinction?
Yes, actually this is why I'm reading the comments here. One of the variants, "вредную" is not the same as unhealthy and seemed wrong to me.
It's one thing to eat something not quite good for you, but it's another thing to eat something outright harmful. Вредную means harmful, неполезную means unhealthy.
I'm a native speaker originally from Moscow.
No, it wouldn't, but I believe «вредная» is used more often in this meaning.
Нездоровый is used to describe an unhealthy state I think (such as when a person is unhealthy) and вредный means harmful,unhealthy etc. Of course the food isn't itself unhealthy it's bad for you
Duolingo generally doesn't accept Russian sentences with the pronoun dropped.
Such sentences only work in some contexts, but since Duolingo doesn't have any context for the sentences, it doesn't allow such sentences. Sentences with pronoun, on the other case, work well almost in any context, so you're encouraged to use them.