K-rationThe K-ration was a United States military ration consisting of three separately boxed meal units: breakfast, dinner, and supper. It was originally intended as an individually packaged daily ration for issue to airborne troops, tank crews, motorcycle couriers, and other mobile forces for short durations. The K-ration differs from other American alphabetized rations such as the A-ration, consisting of fresh food; B-ration, consisting of packaged, unprepared food; C-ration, consisting of prepared, canned food; D-ration, consisting of military chocolate; and emergency rations, intended for emergencies when other food or rations are unavailable.
5-in-1 rationThe 5-in-1 ration was a United States military ration issued from 1942 to the end of World War II. As its name implies, the 5-in-1 provided the needs of five soldiers in a single ration package. Procurement ended with the war, though remaining stocks were issued to troops after the war, as well as distributed as surplus in civilian feeding programs overseas. The 5-in-1 specification remained in effect after the war, and was again used in 1948 for a new field ration.
Mountain rationThe Mountain Ration (or "M-Ration") was a United States military ration developed for use by U.S. troops operating in high-altitude or mountainous regions of the European theatre of World War II. The components of what would become the Mountain ration were developed in 1941–42 by U.S. Army officers in experimental mountain warfare companies, largely consisting of former ski instructors, forest rangers, and other experienced alpine travelers.
Jungle rationThe Jungle Ration (or "J-Ration") was a dry, lightweight United States military ration developed by the U.S. Army during World War II for soldiers on extended missions in tropical regions. Prior to World War II, during field exercises in Panama and other jungle regions, it was determined that standard heavy canned or 'wet' rations were unsuited to soldiers on foot carrying out extended missions in jungle or tropical environments with an abundance of water sources. Testing in Panama by units of the U.S.
C-rationThe C-ration (officially Field Ration, Type C) was a United States military ration consisting of prepared, canned wet foods. They were intended to be served when fresh or packaged unprepared food was unavailable, and survival rations were insufficient. It was replaced by the similar Meal, Combat, Individual (MCI) in 1958; its modern successor is the Meal, Ready-to-Eat (MRE). Development of the C-ration began in 1938. The first rations were field-tested in 1940, and wide-scale adoption followed soon after.