In The Soldier’s Load and the Mobilty of a Nation, then-Colonel S.L.A. Marshall notes, “For it is conspicuous that what the machine has failed to do right up to the present moment is decrease by a single pound the weight the individual has to carry in war”:
Perhaps in Frederick’s day it was necessary for a soldier to carry three days’ food in his pack. Maybe when Napoleon was on the march there was a sound reason for upping that figure from three to four. One can even give Stonewall Jackson the benefit of the doubt for following Frederick’s rule-of-thumb during his campaigns in the Valley. Though observers noted, according to Col. Henderson, that it was the habit of the troops to bolt their three rations as soon as possible and then scrounge around for more.
But why in common sense during World War II did we put infantrymen across defended beaches carrying three full rations in their packs? In other words, nine packages of K rations, weighing roughly the same number of pounds! We did it time and again in landings where “hot cargo” shipments of food were coming onto the beaches right behind the troops and almost tripping on their heels.
One package would always have been enough — one-third of a ration. In fact, we learned by actual survey on the battlefield that only some three per cent of the men along the combat line touched any food at all in the first day’s fighting. And that water consumption was on]y a fifth what it became on the second day and thereafter.