Troops require the following amount of food per hour each:

• Supply troops       = 2, 
• Militia                   = 3, 
• Scouts                  = 5, 
• Pike                     = 6, 
• Swordsman          = 7, 
• Archers                = 9, 
• Supply Wagons    = 10, 
• Cavalry                = 18, 
• Hvy Cav              = 35, 
• Ballista                 = 50, 
• Battering Ram      = 100, 
• Catapults             = 250. 

Troops eat this food whether stationed in the wilds or in your city.

If used to reinforce an allies city, they ally must feed them 
(either with their own food or with food you send them).