British military rations during the French and Indian War
During the French and Indian War, British military rations contained enough food energy to sustain the soldier in garrison but suffered from a lack of vitamins that could lead to nutritional deficiencies if not supplemented by the soldiers themselves through garden produce or purchase. During field conditions, the energy content tended to be too small.
Source: Wikipedia — British military rations during the French and Indian War (CC BY-SA 4.0)