I would paraphrase here because it is difficult to find a corresponding term in English. The closest I can think of in the British context is "free school lunches", but it's not really the same as all schools have canteens here - as we have a full school day here and not just morning or afternoon like in Latin America, and the lunches are funded by vouchers from the government, not communities as in your case.

So, I would paraphrase, e.g. above (although my translation doesn't capture the fact that it is not the school itself that provides the assistance), and then add a translator's note (footnote) explaining the term, exactly as you have done above in Spanish.

I hope this is of help.