My wife and I each have a USGI 3 day pack with 3L water bladders, water purifier bottle and tablets ready at all times. Each pack holds 3 MRE's (the real kind) , a small package of Boullion, Raman noodles, hard candy, gum, 3 - 5 Hour energy drinks, and 4 Hooah bars. HOOAH! 3 days of food to eat on the go. Of course, we pack USGI P-51 can openers (just in case we run across canned food) I keep additional food and a 6 gallon water container in the truck all the times.