I think you may have misread something; €1131 per month, of which €468 is rent and utilities (in Berlin, so still a good rate).
€7.6 euros per week for food is doable, I think, but last time I really tried to optimise that I was at university, in the UK, and it was 2003. (£0.50/day: Lidl instant noodles that they don't even sell any more, Quaker oats packs that aren't sold here, skimmed milk, dried fruit in the oats; I don't recommend reproducing this, it was a game to see how little I could spend without going hungry).
€7.6 euros per week for food is doable, I think, but last time I really tried to optimise that I was at university, in the UK, and it was 2003. (£0.50/day: Lidl instant noodles that they don't even sell any more, Quaker oats packs that aren't sold here, skimmed milk, dried fruit in the oats; I don't recommend reproducing this, it was a game to see how little I could spend without going hungry).