The army ration used at present in training areas, i. e. the type A field ration, presupposes that normal food supplies are available. Its basis is a series of menus for a month, with the corresponding quantities of food required to prepare them. The menus planned must be balanced—nutritionally adequate—and cost not more than the value of the garrison ration at the time and place of issue. They must be prepared two months in advance in order that the quartermaster may have sufficient time to purchase the food. Menus may be modified by authorized persons in accordance with the supplies available or because of changes in the cost of the prescribed food at the time of issue. The menus are prepared under the direction of the corps area commander or by such post or station commanders in his corps area as he may designate.
The menus themselves are usually prepared
HOWE PE. NUTRITIONAL ASPECTS OF FEEDING AN ARMY. JAMA. 1942;120(2):93–96. doi:10.1001/jama.1942.02830370005002