When I was planning this trip, me being the nerd that I am, I laid out everything I thought I would need on a spreadsheet in Excel, and attached a dollar value to it. The goal was to assimilate some kind of budget to figure out how poor I was going to be at the end of the trip. And while the single largest expense was of course gas, food was a very close second.
Of course, like everything on this trip, I did this on the cheap. Frequenting restaurants would have quickly blown through the small funds I had, and even fast food was usually too rich for my budget. I indulged occasionally, but the majority of my food was cooked on a camp stove.
And even then, I could have spent a lot more money then I did. Go through the cooking section at REI, and you'll be amazed at just how much you can spend on fancy-ass freeze-dried backpacking food. You can spend $15-$20 on one meal for yourself if you buy your stuff there. (I know those dinner packets CLAIM they serve two people, but they don't even come close to filling me up) Fucking hell, for that price, why wouldn't you just go to a restaurant?
I found that with a little bit of creativity, you can feed yourself plenty well for a couple of bucks per day at any grocery store. Even going to the store today, when my trip is over, I still find myself scanning the back of instant-dinner boxes, finding what can be cooked with nothing but boiling water in a single pot, calculating in my head how I could pack it onto the bike.
My preferences for food changed as I went through this trip, mostly being altered by what I found worked, and what didn't. Three things that stayed with me the entire trip, and are staples of any long-distance riding, were granola bars, peanut butter, and instant oatmeal.
Peanut butter is an old stand-by for anyone traveling solo. It's got a shit-ton of calories in it, it's very dense, and leaves you surprisingly full after less then 1/4 of a jar. It's got plenty of protein and other vitamins, it doesn't have major problems with freezing or melting, won't easily rot or dry out, and at just a couple bucks for a jar that can last the better part of a week, the cost per calories can't be beaten. The only downside is that jars are sort of bulky to pack, as they don't squish down to fit around other things. But combine with oatmeal and bars, you can get a lot of your nutritional dietary needs taken care of easily with just it and oatmeal.
I became a fucking connoisseur of cereal/granola bars and instant oatmeal. Which stores had it cheapest (Aldi), which had the best flavors in the generic store brands (Albertons), and which gave you the best bang for your buck (Safeway's store brands usually had smaller packets then the others). Instant oatmeal was cheap, easy, and hot, which was exactly what you want when it's 40 degrees and raining. Just boil a cup of water, pour it in a cup, dump in a couple oatmeal packets, and you're done. All that you have to wash is the cup and the spoon.
Granola bars are great as well, but surprisingly expensive when you added it up. Part of it was that I turned to them often because they were so readily accessible and convenient, but if I wasn't careful I would find myself blowing through $10 of granola or cereal bars in one day.
Actually, all the usual snack foods that seemed like a great idea would cost a lot when you actually ate them regularly. Beef Jerky is a fantastic road-trip and touring food on the surface. Lot of calories, nice and salty (I don't really like sweet foods), packs very small, but is SHOCKINGLY expensive. Banana chips, which I love, are very hard to find and quite expensive when I did. Any sorts of candy are out of question, and even dried fruits, while healthy, just don't have the caloric density to make up for their cost.
Some things I started out eating a lot of, but ended up dropping through the trip. Canned soup was one of those things. It's cheap as hell ($$0.49 at Aldi), quick and easy, but the cans are bulky and hard to pack. I soon discovered the instant chicken soup packets, often sold in the perfectly cup-sized serving pouches, but after a few months I stopped using these even. Watery soup just wasn't filling enough, the instant packets were mostly broth with a pitiful smattering of noodles.
One thing that sustained me for the first half of my trip was instant pasta packets. In the US, and less remote parts of Canada, you could get them for around a dollar per pack, and all they required was two cups of boiling water. Some called for a cup of milk, but I made do with a few spoonfuls of milk powder. They were simple enough: Boil two cups water, add contents of pouch, stir for around 7 minutes, and eat. If I'd eaten at any other point in the day, I was usually satisfied with one pouch: If I hadn't eaten in more then 12 hours, two pouches would set me. The only downside to these was that my stove was so finicky about how much heat it put out that it required fairly consistent stirring to prevent burning noodles to the bottom of the pot. And cleanup could have been better, the sauce would sometimes require a bit of scrubbing to get out, which could require a lot of water.
About halfway through the trip, I discovered a replacement for them, actually while I was in Anchorage. Now, this might sound stupid to most people reading this, but . . . I'd never had instant mashed potatoes before.
I was pretty spoiled growing up; my mom was the sort who insisted that all her meals be made from scratch, so I hardly even knew there WAS such thing as instant mashed potatoes. But when I glanced at them at the grocery store in Anchorage, and noticed that all they needed was two cups of boiling water . . . well hey, I gave it a shot.
I found they had a lot of advantages over the pasta packets. For one, prep time: The pasta packets needed to be cooked for 7-10 minutes, and the instant potatoes were done as soon as the water was boiling. They were easier to clean up too, as long as you didn't let the remnants dry to the pot overnight. They cost about the same, and were comparable in terms of how much space they took up on the bike. After discovering them, I hardly bought any more pasta packets for the whole trip.
As the trip wore on, and I got back in the USA after time in Canada, I got progressively lazier about my food. I had started the trip making every effort to cook all of my own food, and if I did eat out, to avoid eating at chain restaurants. After two or three months on the road, though, I'd largely abandoned that. I found that if I didn't feel like cooking, and wanted something quick and easy, I had some options without spending a lot of money.
Subway was an easy one; $5 for a foot-long sandwich was a decent single meal, but wouldn't last me for a day. Little Ceasers, when I could find them, were a GREAT option. They have single-topping large sausage pizzas for $5-$6 available for instant pickup, and eating that in one sitting can last me for most of a day.
But another option turned out to be supermarket delis. Most of them would have 8 pieces of fried chicken for $5-$6, and no matter how hungry I was I could almost never finish that off in one sitting. If I could figure out a way to attach the leftovers to the bike, that was almost two full meals.
That's what I lived on for four months. Peanut butter, oatmeal, cereal bars, instant pasta and mashed potatoes, fried chicken and pizza.
And yet somehow, when I got back to Chicago, I found I'd lost at least 20lbs. When I'd left Antarctica, almost a year before, I was up to 165lbs. But now, as I rested after the trip, my 6'0" frame tipped the scales at 141lbs.
As far as diets go, I can heartily recommend the effectiveness of motorcycle touring.