I didn't have a fridge or cooler actually. Whenever I bought something that would go off, I just made sure it eat it within a day or two, otherwise I just cooked and ate "not fresh" food like rice, pasta, canned stuff and oats for breakfast. I had a small hiking stove that I cooked all my meals on. I'm building my next Jeep now, and it will have a fridge this time as I want to cook and eat better food.
Let me know any other questions you have, I'm very happy to help out.