less than an hour UGR-A: fresh meals prepared on-site (or nearby and transported), requiring refrigeration and a field kitchen UGR-M (formerly UGR-B): meals, mostly dehydrated or preserved, intended for the U.S. Marine Corps UGR-E (Express): meals in self-heating packages designed to feed groups where field kitchens are unavailable Navy Standard Core Menu: meals served to U.S. Navy personnel aboard navy vessels; considered a group ration, but not part of the UGR system Meal, Ready-to-Eat: standard individual field ration First Strike Ration: individual ration designed for use in combat or while moving Soldier Fuel: specialized energy bar found in some MREs The composition of these rations are predetermined in a way to make sure that soldiers are properly fed and equipped with the necessary nutrients in order to maximize energy levels. There are certain levels of nutrients that are recommended by the Military Nutrition Research Committee. As a baseline, it is recommended that there be at least 2,400 kcal in each ration, in which those rations are constructed of different levels of numerous vitamins and nutrients. Ration waste disposal The military prioritizes the burn disposal of the waste because, if not taken care of properly, it can lead to more problems. The goal achieved from the proper disposal includes the elimination of vermin problems, airborne diseases, and preventing any enemy militaries from obtaining the waste to use as resources for themselves or as intelligence. See also Armed Forces Recipe Service History of military nutrition in the United States Notes External links Operational Rations of the Department of Defense, 7th Edition Quartermaster Museum Military Rations, MREs & Food Drilling by the Numbers, Eating by the Letters The Army Family of Rations History of Military Nutrition Research Military food of the United States