Without food things might be a bit on the tough side. Whether you trip with or without money, though times will require you to make tough choices.
Usually you’ll find food pretty easily from the locals. Whether you are couchsurfing or are just staying with hosts, it is part of every culture on the planet to offer food to guests and non-violent and smiling strangers. However, you might end up in isolated situations in which you are required to go look for food yourself.
The concept is fairly easy: every day supermarkets throw away 50% of their food because of expired dates. This food is still consumable. Just before closing hours, you visit the dumpsters at the backside of supermarkets and you usually will find enough food for a day.
The best internet is still the net of people who live in a certain area. Homeless people and beggars know all the special places, and if you’re lucky they’ll be willing to share with you.
Much like dumpster-diving, you ask for food around closing hour in restaurants, bakeries, or grocery stores in general. Try not to be in the way of the regular customers. Just wait till there’s no one, explain them you live without money, and see what happens. Whatever happens, always be thankful and polite. A trick might be to ask them to fill your water bottle first, so they get accustomed by the ‘giving’ concept. One more: always make eye-contact, so you connect on soul level. Don’t look down or away like you’re doing something shameful or ‘bad’.
So that’s it, you’re ready. What are you still doing on this website?