Something many people fail to consider when making their zombie apocalypse plans is that you can starve even when you’re eating. This happens when your caloric intake falls too far below what you are burning.

Let’s say all the easily obtainable gasoline is gone and you’re forced to hike while you carry your world on your back. Even if you’re not wearing a suit of chain mail or lugging a chainsaw as your defense weapon, you might still be carrying between 60 to 100 pounds of gear with you.

Now, you luck out and come across a cache of food someone tried to hide for later. You find a can of pork and beans (427 calories), a candy bar (271 calories), a couple apples (160 calories), two 64-ounce sports drinks (800 calories), a 12-ounce can of corned beef (852 calories), a small bag of peanuts (330 calories), a 10-ounce bag of beef jerky (800 calories) and two chocolate energy bars (480 calories).

How many days worth of nutrition is that? Five if you ration it? Or maybe four to play it safe?

Wrong. That cache is a total of 4,120 calories, meaning it falls just short of the U.S. Department of Defense field ration of 4,500 calories per day for strenuous work.

Among hiking organizations it is generally agreed that a man carrying a heavy pack and trying to make between 15 and 20 miles per day should try to consume as much as 6,000 calories per day.

So how do you survive when the food supply runs short?

Remember these three tips: travel light, pace yourself and clean your plate.

This article originally appeared in Zombie Apocalypse Monthly issue 2. The entire magazine can be downloaded for free here: http://www.magcloud.com/browse/issue/408784.