...food (and ofcourse water)? if so which ones?

ofcourse you can. I've planted tomatoes, peppers, and beans and it works. Even if you don't have a big enough pot go ahead and plant it. You won't get as many but you will still get some veggies. I found peppers growing at the nursery when they were in the small 4 pack black containers can you believe that? If they can grow in that tiny space than you will get some veggies in your pot.

I don't know of any vegies you could grow in a pot . The prepared ground is better...The plants like, tomato,peppers etc.can be put in the ground in the tiny pots if they are the kind(paper) that would deteriate...

If you have enough light you can grow tomatoes and peppers. There are even hanging pots for tomatoes where you can actually grow the upside down. If you have a way to stake them you could grow cucumbers and beans. Just have large pots, sunlight, plenty of water and I would use Miracle Grow as recommended on the label.

Yes, you can grow vegetables in a pot. Tomatoes, pepper, onion, lettuce, cucumbers. It depends on the size of plant, which pot you may need. You don't get as much produce as you would in the ground. Use Miracle-Grow soil and you need to water daily, especially on very hot days.