many more calories per day than a soldier marching over cleared roads in temperate climates. Nevertheless, one K-ration per man per day would remain the basis of issue, even for mountain troops fighting at high altitudes and infantrymen fighting in the thick jungles of Burma. Military personnel also supplemented with various other rations throughout the war such as with the C-ration when needed. Evaluation and field reports The C-ration was the only ration comparable to the K-ration in widespread issue, with six cans comprising one full ration. Introduced in 1938 it was significantly heavier, with less variety in meals, but had more protein. While fighting in the European Theater of Operations, the US Army discovered that troops also quickly got tired of the K-ration, some being forced to eat it for days, or rarely, in excess of a week on end. As it was based on an emergency ration, a complete K-ration was for the ration (breakfast, dinner and supper), fewer than required by highly active men, especially those working in extreme heat or bitter cold, and malnutrition became evident. The packaging of the K-ration into separately described daily meals may have intensified this problem by leading commanders to assume that daily caloric intake was sufficient. An extensive 1943 field report from the European theater noted that none of the packaged rations were recommended for continued use by active troops for periods in excess of 10 days. A survey of troops in the forward areas and evacuation hospitals of the Fifth U.S. Army serving in the Italian campaign noted that almost all soldiers questioned in infantry, engineer, and other mobile forward units said they had lost weight since the beginning of the Italian campaign. Surgeons commented upon a noticeable decrease in body fat and wasting of muscle, requiring copious feeding and rest, as well as ascorbic acid (Vitamin C). The K-ration was also criticized for its performance in the China-Burma-India (CBI) theater of operations, where difficulties in supply from bases in India had resulted in widespread and monotonous use of the K-ration for light infantry forces of the United States, as well as Nationalist China and the United Kingdom. Many soldiers, including the U.S. unit known as Merrill's Marauders and British Chindit forces in Burma, had for five months lived primarily on K-rations, supplemented by rice, tea, sugar, jam, bread, and canned meat rations, which were dropped to them by