Testing in Panama by units of the U.S. Army showed that a dry ration that could be easily decanted into waterproof bags for individual use would best suit jungle infantrymen carrying their own supplies while on foot, to be rehydrated as necessary from local water sources.
[2] In the original issue of the Jungle ration, all food components were dried or dehydrated and could be decanted from their tins or packages into individually carried lightweight waterproof bags.
[5][6] This criticism arose as a result of the Army and Quartermaster Corps' failure to incorporate previous infantry field reports and test data to SRL staff and dieticians.
[2] The absence of a lightweight, yet sufficiently nourishing and palatable compact field ration had serious consequences for some U.S. troops later in the war, most notably the soldiers of Merrill's Marauders.
[9] The jungle ration was repeatedly altered during its existence, as Quartermaster Corps officers substituted less expensive or heavier canned components (such as evaporated milk).