In 1861, the Army of Virginia published “Directions for Cooking by Troops in Camp and Hospital”
An Army camp cooking manual, the content of which was written by Florence Nightingale. The recipes emphasized meat and milk (for protein) and whole grains, fruits and vegetables (for carbohydrates). The first “US Family Food Guide (1916)” was published 35 years later, with essentially similar recommendations.
Civil War historian William C. Davis, in A Taste for War: The Culinary History of the Blue and the Gray, 2003, page ix:
“No one completely escaped the rotten meat, the worm-infested bread, the illness from want of fruits and vegetables, or the utter absence of even the basic principles of nutrition and a balanced diet.”
Cooking In Camp. Repository: Library of Congress Prints and Photographs Division Washington, D.C. 20540 USA http://hdl.loc.gov/loc.pnp/pp.print