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.
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.