Our group put it to a vote and 2 of 3 voted yes we want to keep track of food. I must implement it and I want to do it in the best way possible.
I've always been familiar with 3 weeks without food and your body is prone to fail. In this consideration, when presenting food items to my players, how much food do they need to keep fighting fit?
In the D&D 4E DMG:
When deprived of food, water, or air, the rule of three applies. An adventurer can handle three weeks with out food, three days without water, and three minutes without air outside of strenuous situations. After that, such deprivation is a significant test of a PCs’ stamina.
After which they provide the relevant checks.
I've dove a bit further back, which I do sometimes because not everything is in every edition, to D&D 3.5E DMG and found:
Characters might find themselves without food or water and with no means to obtain them. In normal climates, Medium characters need at least a gallon of fluids and about a pound of decent food per day to avoid starvation. (Small characters need half as much.) In very hot climates, characters need two or three times as much water to avoid dehydration.
I may just hybrid this aspect in but before I do, I want to know how much food is considered substantial in 4E?