If you’re going to be backpacking in Spain, you’ll probably want to cook a bunch of meals in your hostel kitchen, and this is a good way to keep your food costs down. Head to a local market near to where you’re staying and stock up on ingredients. The good news is that food in Spain doesn’t have to be expensive, so you can definitely afford to eat out regularly.
You can get cheap tapas and sandwiches meals for between 3-10 EUR. If you want wine included, expect to spend about 10-15 EUR per meal. A good restaurant meal will set you back around 13 EUR. If you go out for paella, drinks, or appetizers, then you should plan to spend around 20 EUR for a meal. Spain has a lot of expensive restaurants, and meals there begin around 30 EUR with a drink.
Fast food like McDonalds and Maoz cost around 7 EUR. Groceries will cost around 25-30 EUR per week, especially if you stick to the copious local markets around the country. You’ll find the cheapest (and freshest!) produce and meat at the local markets.