Aaron's post on Mac and Cheese generated quite a few comments, so I thought I would build on his achievement with some lessons that I received from cold weather training with the USAF, and two different Winter Search and Rescue teams that I have belonged to, Marquette County, MI and Multnomah County, OR.
All that training stressed "food as fuel". It's well known that your food requirements can double for outdoor work in cold weather. An 18-50 year-old man (militia age) might use 3,000K (calories) a day working at a desk, indoors. Doing moderate work outdoors in warm weather might raise that 1-2,000K, but add in the calorie-robbing cold and you can add another 1-2,000K. Metabolism studies in loggers working out in moderate cold (35-55f) showed that in the "Misery-Whip" or springboard logging days from 1850 to 1945, a logger could eat 6-10,000K for breakfast, another 4-5,000K for lunch and 5-7,000k for dinner and lose weight. That's at least 15,000K and as much as 22,000K. A pound of weight equals 3,200K, so our loggers should have been gaining 5-6 pounds a day. After they had worked at it for a couple of months, their weight stabilized on that caloric intake.
The Army plans on feeding two MRE's a day, and they are 6,000K if memory serves. That's 12,000K for an active soldier. In field research, few soldiers, given the chance, consumed all of the meals, and probably existed in the field on 5-7,000 calories.
Let's say our little army takes the field for a day's operations. How much Mac n' Cheese are we going to have to prepare, per man, to feed the troops?
From my pantry, I retrieved a box of Kraft "The Cheesiest" "Original Flavor" Mac n' Cheese, net weight 7.25 oz. If I make it according to the instructions, with all the margarine it requires, the ENTIRE BOX has only 1,140K in it. About 70%RDA of fat, 50% of Carbs and 60% of the protein. Mind you, the RDA is a minimum-to-maintain figure if you are not exercising. You'd have to eat about 5 boxes per day of this staple, a fairly bulky amount (in the gallons) to exist for long as an infantryman.
It's survival food. An army fights on it's stomach, as a logistician of WW1 observed (may have been Gen. Pershing). Mac n' Cheese might be good midnite rats to keep you making heat in your sleeping bag at night, but it ain't gonna power you far during the day. For that, you need more protein and more carbs, and a little more fat. There are powdered supplements that will give you huge protein and carb numbers with a half-liter milkshake. The body-builders use them to pack on those huge decks of pecks. In a militia situation, we are concerned with keeping our baggage train as small as possible, so in my outfit, we will probably pack and use the supplements. They can be premixed and issued out to be carried in a light rucksack (think seal-a-meal packs). They require no cooking, and will keep 6-8 hours unrefrigerated.
In a realistic S.H.T.F. situation, there will probably be kids and wives in camp. They can get by on the Mac n' Cheese, but if we're going back to the city to take back what's ours, we'll need better fuel.