Informally, it's "απαγορεύεται να τρως" (second singular person is used in greek for depersonalised sentences). Formally (for example in a metro station) you will hear/see "απαγορεύεται η κατανάλωση τροφίμων και ποτών= the consumption of food and drinks is forbidden. So, in other situations, you can use a noun associated with the verb. P.e: it's forbidden to run and to talk in the library=απαγορεύεται το τρέξιμο και η ομιλία εντός της βιβλιοθήκης (lit: running and speech/talking is forbidden in the library)
απαγορεύεται means something like "it is forbidden" -- the thing that is forbidden is the situation "I eat" or "you eat" or whatever.
Απαγορεύομαι would mean that you as a person are the forbidden thing -- as if your very existence is forbidden.
So it's essentially always used in the third person, either singular or plural, depending on how many things are forbidden.
Ok thank you. I may be asking a stupid question, however I am confused by this. Απαγορεύεται να τρώω has to refer to oneself because of τρώω. In another sentence in this exercise it states, Απαγορεύεται να πηγαίνω means it is forbidden to go. So why can that sentence (the second one) be a generic statement in the first person singular but not this sentence?
I personally wouldn't opt for that translation for the second sentence. The present tree was created by the then Greek team about 2 years ago. The present team comprises very few members of the previous one, so, sometimes, we have to deal with/explain sentences that have not been created by us, that's why we hope that Tree 2 is going to be more consistent. Not trying to discredit anyone, obviously, just explaining why we sometimes don't agree with some of the sentences of the course.