Norway is an affluent country in Scandinavia. The dumpsters are full, especially of fresh fruits and veggies (mostly exotic like mangos avocados and bananas, tonnes of them but also of any other, from tomatoes to strawberries, blueberries, anything your appetite and taste may want) .
Dumpster diving isn't commonly known in Norway. The winters in Norway can be really cold (which means a good "fridge" for dumpstered food). Check Wintertime diving for tips on how to dive in the winter/cold.
Take as much food across the border as you can possibly carry, but no worries, when you will have finished it the dumpsters will surely fill your stomach, prefer small villages and towns than big cities since there is more food and dumpsters are (almost) always unlocked; plus food like oat, flat "fullkorn" bread, cooked legumes in metal or tetrapak boxes like beans, chickpeas, lentils, etc are definitely cheap or at least affordable (around 1E per piece but often even less) and constitute a good way to buy something in order to "borrow" from supermarkets (since the security is not really active) the expensive food you need and can't pay.
In Kiwi you can go on a hunt for vegetables or fruits that simply differ from others, then show the ones you found to the employees and eventually get the "proper" or new product - and sometimes even the "bad" looking one - for free. Also the cinnamon and vanilla buns are worth checking if they are expired, usually there is at least one bag amongst them - or ten. You however do get any expired product for free if you find it in Kiwi. As the supermarket does not want you to profit too much from it, you can barely find other things within the store nowadays. Furthermore the Norwegian government passed a new law in July 2014 according to which supermarkets are actually not allowed to give out expired products anymore. Kiwi seems to have a kind of special policy though. A few supermarkets and gas stations around smaller towns, especially further up North, will however still allow you to take their expired products if you are lucky.
Update summer 2016: it seems that getting expired food for free from Kiwi doesn't work anymore (at least in 1 supermarket where it worked a year ago). Dumpster-diving is still very possible.
Same as in the rest of Scandinavia you can collect plastic bottles and cans, take it to the supermarket and get money. For a can or small plastic bottle(500ml or less) you get 1Kr and for biger bottles you get 2,5 Kr so on the way to shop you can collect bottles and have enough money to buy some food if dumpsters doesn't work there. When you meet some event like a music festival you can earn good money wit collecting( more than 10 euros per hour is verry possible on outdoor events). You can give back only Norweigian bottles.
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