If you are wondering why WW1 American soldiers were called “doughboys” here’s what wiki has to say about it:

The origins of the term are unclear. It was in use as early as the 1840s.[3][4An often cited explanation is that the term first came about during the Mexican–American War, after observers noticed U.S. infantry forces were constantly covered with chalky dust from marching through the dry terrain of northern Mexico, giving the men the appearance of unbaked dough.[5] Another suggestion also arises from the Mexican–American War, and the dust-covered infantry men resembled the commonly used mud bricks of the area known as adobes.[5] Another suggestion is that doughboys were so named because of their method of cooking field rations of the 1840s and 1850s, usually doughy flour and rice concoctions baked in the ashes of a camp fire, although this does not explain why only infantryman received the appellation.[5]