It does not seem completely plausible to purchase one sandwich and get four meals out of it. But trust me, it's definitely doable, especially when you are a strapped-for-cash traveler with limited space for anything in your backpack. Trekking across various regions of the globe leaves very few options for packing--and eating--extravagantly, so making the most out of something little is imperative.
I know from personal experience that you can jam a whole lot into one backpack, even if you think it is not big enough to carry it all. On my seven-week trip through Europe, I managed to fit two pairs of jeans, four pairs of shorts, 10 tank tops, three cute tops, a dress, 20 pairs of underwear (you can never have enough), eight pairs of socks, five bras, a pair of tennis shoes, flip-flops, a sweatshirt and a rain jacket all into my one bag. And there was still enough room to hold my toiletries, camera, camera charger, outlet converters and all my money, credit cards and passport. So where does the sandwich come into play?
Well, just as I had to take advantage of what little room I had in my backpack, I had to stretch every meal to the limit. That bag of chips we bought on our last day in Nice had to make it through a five hour train ride to Switzerland, a late night check in at the hostel that left little room to eat, and a whole day of sightseeing through the town of Interlaken. A small jar of peanut butter and bag of pretzels was my go-to snack option for a week, not to mention a full meal or two. And that sandwich, well, let's just say one single panini bought in Italy had to survive at least two days, meaning it was my lunch, dinner, breakfast and lunch again. So how do you effectively transform what is considered to be one full meal into four small ones?
For those of you going on extreme travel expeditions with lots of hiking, biking, walking, etc., I recommend not heeding this advice. You need way more food to sustain that level of activity, but there are ways to keep the food spending down even when you have to eat a lot. If you are traveling with friends, split as much as you can, and get larger portions, so you can always store some away for later. If you are staying in hostels with a kitchen, buy items at grocery stores and make your own sandwiches or cook up a big pot of pasta. Trust me, buying a $3 loaf of bread, a pound of sliced meat and some cheese will go alot further than spending $6 on one sandwich.
The art of rationing is definitely helpful while traveling. It helps save money and lightens your load--in more ways than one. And while I would not recommend doing it at any other time--though I just pulled it off this week--it is a good skill to keep on hand for a variety of other circumstances.