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Institute of Medicine (US) Committee on Military Nutrition Research; Marriott BM, editor. Not Eating Enough: Overcoming Underconsumption of Military Operational Rations. Washington (DC): National Academies Press (US); 1995.

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Not Eating Enough: Overcoming Underconsumption of Military Operational Rations.

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7Evolution of Rations: The Pursuit of Universal Acceptance

Gerald A. Darsch 1 and Philip Brandler


The logistical task of providing subsistence for military personnel has been critical throughout history. Frederick the Great of Prussia is credited with having defined an army as a group of men who demand daily feeding (Frederick II, 1966). Military rations are no less important today, and, in fact, the importance of sound nutrition to the performance of modern, high-technology military personnel may be even more critical than in the past. Simply put, food fuels the fighter, and inadequate fuel for fighters will bring the military machine to a grinding halt.

The U.S. Army Natick Research, Development and Engineering Center (NRDEC) is responsible for the Department of Defense (DoD) Food Research Development Test Evaluation and Engineering (RDTE&E) Program. The DoD Food RDTE&E Program was established as a joint service program at NRDEC to provide for a coordinated and integrated program supporting the requirements of the four services and other DoD components. The food program encompasses the design, development, and evaluation of new and improved operational rations, packaging, foodservice equipment, and feeding systems.

Operational Rations

The American military addresses the task of feeding its personnel with a family of operational rations that are designed to provide necessary nutrition regardless of the tactical situation. The family of rations is currently composed of the Meal, Ready-to-Eat (MRE), which is the standard individual combat ration, and three field feeding options, which provide hot group rations to soldiers: Tray Ration (T Ration), B Ration, and A Ration.

Numerous constraints and considerations must be addressed by a ration developer, particularly in the case of individual combat rations, if an acceptable ration is to be provided to American military personnel. Six constraints that must be addressed by any developer of food products are:

  • acceptance,
  • nutrition,
  • wholesomeness,
  • producibility,
  • cost, and
  • sanitation.

In addition, 10 constraints that are unique to the military must also be addressed by developers of rations. They are:

  • Universal acceptance. Goya Foods, for example, targets customers with Hispanic heritage. Its products are selected and prepared in accordance with the tastes and expectations of this niche of the wholesale and retail food market. The American military, however, draws its population from ethnic backgrounds representing just about every nation in the world and, further, from all regions of the United States. Because these regional and ethnic preferences must be considered, the selection and formulation of specific products for military rations are difficult tasks.
  • Worldwide environments. The U.S. Army has, and in the future will increasingly be, a force projection army, that is possess the capability to effectively move large numbers of U.S. based troops to any global location to engage in combat and win decisively. As a result both personnel and material, particularly food and related supplies must be transportable and consumable in any environment in the world. Although many manufacturers can package their items for a specific local market, American military rations must be formulated and packaged to be shipped, stored, prepared, and consumed in temperatures ranging from -60¹F to 120¹F (-51¹C to 49¹C).
  • Air delivery. While American food processors must package their products to ensure protection during rail or truck transportation, the American military often must deliver its rations to combatants by air. Air delivery involves not only the considerations necessary for air cargo transport, but also those for parachute drop or even free fall. Therefore, rations must be packaged to withstand extremely rigorous and rough handling.
  • Weight and volume. American food processors are eagerly striving to remove as many calories as they can from products they prepare and market. In contrast, the American military must be concerned with maximizing the caloric content of food products while minimizing the weight and volume. In most cases, a force projection army must transport its own food and cannot afford to waste valuable space on board aircraft and ships to store bulky food items. Further, once the Army is deployed into the field, neither space nor weight can be wasted on trucks or in the load-bearing equipment of individual soldiers.
  • Shelf life. A minimum shelf life of 3 years at 80¹F (26.7¹C) is required in order for rations to be placed in prepositioned war reserve stocks. This extended shelf life—as opposed to commercial shelf life, which is 18 months—is necessary for two reasons. First, a shrinking Army may require that rations remain in prepositioned war reserves for longer periods of time since the available number of military consumers of that stock will shrink. Second, extended shelf life ensures that the quality of rations can be maintained for long periods of time in high heat environments, which reduce considerably the shelf life of food products.
  • Self-heating. Self-heating ensures that soldiers will have hot meals at all times with a consequent increase in acceptance and consumption of the food items presented. In many cases soldiers simply do not have the time to stop and conventionally heat a ration.
  • Performance enhancement. The Army would like to use the ration as a force multiplier for its soldiers by providing naturally occurring food ingredients to extend the mission endurance of each individual combatant. Research indicates that specific nutrients provided in appropriate quantities can enhance performance, both physical and cognitive (QMC&S, 1994), and this avenue is being explored aggressively.
  • Modularity. Modularity involves the construction of a nutritionally complete ration using preassembled subcomponents. It permits tailoring of ration systems capable of meeting a broad range of requirements through interchanging a small set of ration components.
  • Boredom. Limitations in the logistics system require that the menu cycle length be restricted. The military transportation assets, specifically aircraft, ships, and vehicles, are limited in number and must transport all combat equipment and supplies to include food. Because of the physical space constraints coupled with the necessity of maintaining a manageable inventory, a 10-d menu cycle has been established by the Army. Therefore, items must be selected from the menu cycle in an appropriate time cycle to delay menu boredom for as long as possible.
  • Biological and chemical threats. Although military rations have historically been packaged and processed to avoid the possibility of biological contamination from naturally occurring organisms, war-time scenarios of the future suggest that rations might become contaminated by the effects of biological and chemical warfare. Military rations must be packaged to counter those threats.

Current and Future Operational Rations

Meal, Ready-to-Eat

The Meal, Ready-to-Eat (MRE) is an operational ration currently configured as 12 menus, with all 12 menus packaged together in a shipping case. Each menu weighs 11/2 lbs (0.7 kg) and comprises six to eight components. Most of the components are packaged in flexible trilaminate material, and some of the components, the entree for example, are retort processed 2 to achieve commercial sterility. All components are nutritionally balanced in accordance with the Office of the Surgeon General's (OTSG) requirements as stated in AR 40-25 (1985). The MRE is intended for use in conflict situations where cooks cannot prepare group meals by virtue of the tactical environment.

The first date of pack for the MRE was 1981 (MRE I). In 1983 a field evaluation was conducted with the 25th Infantry Division over a 34-d period in which the military personnel involved ate nothing but MRE Is three times a day. Although troops rated the ration as acceptable, consumption rates were low: only about 60 percent of the calories provided were actually consumed. However, the exercise resulted in numerous suggestions on how to improve the MRE I.

During a follow-on field evaluation in 1986 of an improved MRE, again with the 25th Infantry Division, both acceptability and consumption of the MRE increased as a result of the improvements made. Based on these findings, a significant number of changes were made to the MRE starting with the 1988 date of pack (MRE VIII). These changes included replacing 9 of the 12 entrees with new ones, increasing entree size from 5 to 8 oz (from 143 g to 229 g), adding commercial candies to 4 more menus, adding hot sauce to 4 menus, and adding a cold beverage base to all 12 menus.

The process of MRE improvement has continued based on surveys of troop feedback from the field, including early feedback from Operation Desert Shield/Storm (ODS); from focus groups; and from individual interviews with soldiers. As a result starting with MRE X, commercial freeze-dried coffee replaced the old military specification spray-dried coffee, hot sauce was added to all 12 menus, wet pack fruit was provided in place of dehydrated fruits, and commercial candy was included in four more menus for a total of 8 menus with candy.

During ODS, MREs were eaten by many troops for periods far in excess of their design. The surgeon general had endorsed the use of MREs as the sole source of food for periods of 10 days or less; however, during ODS troops had to subsist on MREs for periods of up to 60 days or longer. As a consequence during the operations, three changes were quickly made either to supplement the MRE or to enhance its acceptability. All three items were procured in bulk and provided to members of the Armed Forces during ODS. First, a shelf-stable bread in a standard MRE pouch was developed. Through the innovations of water activity control, new ingredients, and intrapackage atmosphere management, this bread can remain in a fresh-list state for up to 3 years (Brandler and Darsch, 1993). Second, a high-heat-stable chocolate was developed, in coordination with industry, that would not melt in the heat of the desert environment, and that would be highly palatable. While a high-heat-stable chocolate had been developed in the past, its waxy taste and nature precluded its high acceptance. A third development was the flameless ration heater, which uses an exothermic chemical reaction to produce heat rather than a flame (Brandler and Darsch, 1993). This device provided a quick and easy method for troops to heat the MRE entree, which increased both its acceptance and consumption rate.

Despite these innovations and the earlier improvements made to the MRE, the ration was not without criticism during ODS. Because it was necessary to use prepositioned was reserves, some rations provided to soldiers during ODS were 4 to 5 years old or even older, and many had been subjected to cycles of temperature that had accelerated the degradation process. In some cases difficulty in maintaining the logistics chain for A, B, or T Rations, specifically the inability to provide foodservice equipment to prepare bulk food, precluded the use of group feeding options. As a result, soldiers had to subsist on MREs for extended periods of time. This problem was further exacerbated by command decisions in some divisions whereby MREs had to be eaten by all division members if even one soldier had to eat it by virtue of his tactical situation. As a result, opportunities to provide variety in food options to troops (e.g., group meals) were ignored. An after-action analysis conducted during a Joint Service MRE Forum established in 1991 to review the performance of the MRE during ODS concluded, however, that the MRE was not problematic when used properly. This group suggested that a policy of replacing up to 2 menus per year of the 12 provided in each case would ensure that new items would be available when the MRE is used. Since its establishment in 1991, the Joint Service MRE Forum (now referred to as the Joint Services Operational Rations Forum [JSORF]) is held once a year to continue to endorse enhancements to the MRE.

This recommendation of the Joint Service MRE Forum underscored NRDEC's commitment to a policy of continuous product improvement for the MRE and permitted acceleration of the testing and fielding of new innovations through the Soldier Enhancement Program (SEP)3. Beginning in FY 1991, and continuing, a number of new MRE menus are tested each year with soldiers in field environments who are deployed on field training exercises. The results are presented to the Army's Subsistence Review Committee (SRC), which is chaired by the deputy chief of staff for logistics. Following his approval, the recommendations are presented to JSORF, with representatives from each of the Armed Services, for endorsement by the JSORF. Specific changes in the MRE that have resulted from this process since FY 1991 include the following:

  • chicken a la king and barbecued meatballs were replaced with smokey franks and pork chow mein in both MRE XIII and XIV;
  • smokey franks and pork chow mein were supplemented with new snacks: potato sticks and chow mein noodles, respectively;
  • highly dense nut cakes were replaced with pound cakes in five different flavors in three menus;
  • six of the 12 Kool-Aid style beverages were replaced with aspartame-based fruit flavors; and
  • a flameless ration heater was included with all MRE menus to ensure that a heating capability was provided with the meal.

As a result of follow-on field testing during 1992, SRC and JSORF decisions on MRE XV included the following:

  • ham omelet and corned beef hash were replaced with grilled chicken breast and chili macaroni;
  • a third snack, tavern nuts, was added to the menu cycle;
  • the old style brownie was replaced with a new chewy brownie;
  • a freeze-dried fruit was replaced with wet pack pineapple; and
  • six of the freeze-dried coffees were replaced with sweetened lemon tea.

Many of the items now included in the MRE are standard commercial items. In fact, 44 percent of the MRE components, including some of the new entrees, are commercial items.

During ODS, the Armed Forces Chaplain Board identified yet another need for ration development to meet the needs of personnel with specific religious dietary observances and restrictions. As a result, the development of a Multi-Faith Meal (MFM) was endorsed by the SRC and the JSORF in FY 1993. Pending SRC and JSORF approval, up to two MFMs per MRE shipping case will be included in MRE 1996 date of pack and will replace two of the less acceptable MREs.

Six MFMs have been designed utilizing nondevelopmental, commercially available kosher and vegetarian entrees and compatible MRE components. These meals were the subject of field tests during the first quarter of 1994 with military personnel of the 18th Airborne, Fort Bragg, and of the U.S. Marine Corps, Camp Lejuene. Military personnel both with and without religious dietary restrictions were tested to ensure universal acceptability.

The NRDEC program of continuous MRE improvement continued with a field test in the fourth four entrees, breaded chicken, grilled beefsteak, chicken parmigiana, and Hawaiian chicken; two starches, buttered rice and Mexican rice; and a new spread, jalapeño cheese. In the first quarter of 1994 a number of packaging improvements were also field tested. These included:

  • commercial-like graphics and logos since behavioral data indicate that commercial packaging results in greater acceptance and consumption;
  • incorporation of easy-open features since existent MREs are somewhat difficult to open;
  • utilization of horizontal form, fill, and seal packaging, which decreases the bulk of and facilitates ease of carrying the meal; and
  • incorporation of a biodegradable spoon to make the MRE more environmentally friendly.

Those changes that are implemented will probably affect MRE XVII.

In FY 1994 NRDEC also began an analysis of the effects of increasing the number of MRE menus from 12 to 18 to 24 as a strategy to overcome menu monotony and to allow the use of the MRE as a sole source of food for extended periods of time. The analysis will identify, and validate through field testing, the optimum number of menus that positively affect consumption of the MRE. Data will be presented to the OTSG, SRC, and JSORF so that changes to MRE XVIII and beyond can be made.

Tray Rations

The most tactically versatile of the group rations is the Tray Ration (T Ration), which is made up of heat-and-serve prepared foods in half-steam-table-sized rectangular cans. Each meal is nutritionally balanced in accordance with AR 40-25 (1985) and includes an entree, a vegetable, a starch, and a dessert. The T Ration provides hot group meals with limited personnel and minimal equipment.

First introduced in FY 1985, the T Ration initially provided a 14-d breakfast and a 14-d lunch-dinner menu. All necessary components, including napkins, knives, forks, trays, and so on, were contained in modules for 36 military personnel. A field test in FY 1989 that evaluated a 14-d menu versus a 10-d menu provided a baseline assessment in a temperate environment. Because the 14-d did not seem to provide any significant benefit, the T Ration was converted to a 10-d menu. Entrees in the 10-d breakfast menu include sausages, creamed ground beef, and a variety of omelets. The lunch-dinner entrees include such items as solid muscle chicken breast, lasagna, and ground beef pattie with a shelf-stable roll.

In FY 1991 the module size of the T Ration was reduced from 36 to 18 soldiers since the 36-person module was simply too heavy for an individual soldier to handle. Also, in FY 1991 an 18-soldier arctic module supplement was added to the T Ration system to provide the additional calories required in cold weather operations. The arctic module augments the standard 18-soldier module with additional hot beverages, snacks, and specialized clam shell type trays that help with heat retention of the food.

The T Ration has been the subject of a product improvement program at NRDEC, and menus have been restructured on a continuous basis to eliminate less acceptable items and to add new, more highly acceptable items. All substitutions are made on the basis of field tests in the same manner as with the MRE. New T Ration components recently developed and field tested include a new family of high-quality, freeze-dried scrambled eggs, chicken teriyaki, and boneless barbecued pork ribs. As with the MRE, the data are presented to the SRC, JSORF, and OTSG for endorsement and approval.

B Ration

Another group ration is the B Ration, a cook-prepared meal that requires a field kitchen. However, all ingredients used to prepare the B Ration are semi-perishable, and therefore, no refrigeration is required. Most of these semi-perishable ingredients are standard institutional-type ingredients such as flour, sugar, and large (# 10) cans of vegetables and meats. In addition, there are 13 unique items that are either dehydrated or chunked and formed. Preparation of these meals in the field using field kitchens is a demanding task that requires considerable culinary skill. The B Ration has not changed substantially since the 1970s; therefore, a modernization program is under way. Advancements in ingredient and food processing technology will be incorporated to increase quality and reduce cost. The 10-d breakfast and dinner menus of the B Ration are prepared using the Armed Forces Recipe Service.

A Ration

The third and final group ration is the A Ration, which is a meal prepared by cooks in a field kitchen where refrigeration is available and chilled and frozen products can be provided. Like the B Ration, this meal requires considerable cooking skill and demands careful inventory management due to both the perishable nature of some ingredients and the total number and quantity of ingredients required to prepare and serve meals. Like the B Ration, the 10-d menu of the A Ration is prepared using the Armed Forces Recipe Service.

Unitized Group Ration

To simplify the logistics of ordering and to ensure that all necessary ingredients to prepare group rations are provided, an integrated unitization concept called the Unitized Group Ration (UGR) has been developed by NRDEC in conjunction with the U.S. Quartermaster Center and School (QMC&S) at Fort Lee, Virginia. The UGR integrates into a unified system the A Ration minus the perishables, the B Ration, the T Ration, and additional brand-name items that can be quickly prepared. The UGR contains 15 breakfast menu options (5 each of rations A, B, and T) and 30 lunch-dinner menu options (10 each of rations A, B, and T). Each of the meal options is unitized in six containers and provides all of the ingredients, trays, utensils, napkins, condiments, and so on, necessary to feed 100 military personnel. The six containers make up one layer of a pallet, and four layers constitute a pallet load. This system maximizes the efficiency of group feeding in the field and reduces the number of individual food components (e.g., canned meat, flour, salt, pepper, tomatoes, etc.) a cook must order to prepare a meal to one-tenth the number formerly required.

The UGR has been evaluated in a series of four field trials, which have indicated that the UGR simplifies logistics and significantly reduces the issue time to deliver rations to field units. The UGR also accommodates the Chief of Staff, Army-approved recommendation that one A or B meal be served to troops in the field, if the mission, enemy, troop, terrain, and time permit (QMC&S, 1994). A future field test will evaluate what has been designed to be an optimized configuration for the UGR with the maximum number of acceptable ingredients and menu options incorporated. Pending approval the UGR will go to the Defense Personnel Support Center no later than the second quarter of 1995 for procurement.

Nutritional Labeling

Nutritional labeling of operational rations is an area of concern for ration developers. The need for nutritional information by military personnel has been identified not only by direct feedback from personnel but by the Office of the Surgeon General and the Committee on Military Nutrition Research (IOM, 1991). During Operation Desert Storm/Shield, troops requested nutrient information, and it became clear that many were misinformed about their rations, particularly with respect to nutritional content. A program is now in place to develop guidelines and labeling concepts for rations that are in accordance with nutrition policy and recommendations of the U.S. Food and Drug Administration, the U.S. Department of Agriculture, OTSG, and the military. An appropriate user evaluation of nutrition labeling concepts will be conducted by NRDEC to ensure that the military consumer finds them useful. Pending approval, modified nutrition labeling will be included in or on operational rations in the future.

Future Field Feeding Concepts

A technology-based program is under way at NRDEC that addresses a new family of operational rations intended to meet the food needs of the future battlefield. The effort is aimed at developing self-heating rations that have fresh-like quality, yet are shelf stable and suitable for both individual and group feeding. The two major components of this ration system include a self-heating individual meal and a self-heating group meal. These particular meal concepts will be tested, fielded, and further improved through technology changes in processing, packaging, and heating. Incorporation of this technology into the rations system is scheduled for sometime after the year 2000.

For the self-heating individual meal, developers are seeking to utilize a tray or shallow tub configuration similar to individual commercial tray meals such as Top Shelf meals, manufactured by Hormel Incorporated. The meals are designed to be nutritionally complete, including a meat, vegetable, starch, and dessert. Entrees consist of popular foods such as whole muscle meats. One of the concepts under consideration calls for the integration of both the heater and activating solution in the meal package so that the soldier does not have to add water to the package to initiate the heating process. An initial demonstration with limited technology was completed in 1993 with positive results. Pending further technology development, demonstration, and military services approval, the concept is scheduled to move into advanced development sometime in FY1996.

The self-heating group meal ration system, also referred to as ''a kitchen in a carton," will require no foodservice equipment. Food components (e.g., entree, vegetable, starch, and dessert) will each be contained in large, 6.6-lb (3-kg) retort pouches. Heaters built into the trays that hold the retort pouches4 will "fuel" a canteen of water that is automatically metered to the various heating pads in the trays. The heating system will ensure that each food component will be hot in 30 minutes and will remain hot for an additional 5 to 6 hours if needed. Meal modules will include all accessories and utensils in the same way described earlier for the modularization of UGR and T Rations, and each module will provide a complete meal for 18 soldiers. An initial demonstration of the self-heating group meal to military foodservice personnel was completed in 1993 with positive results. This meal concept is scheduled to move into advanced development in FY1996.


As the United States is the most technically advanced country in the world with respect to weapon systems, so too are the ration systems that have been fielded and that are currently under development. Success in the development of these rations is due not only to the technology programs conducted by the U.S. Army Natick Research, Development and Engineering Center, but also to the feedback received from military personnel; to the nutritional scientific evaluations and analyses conducted by the Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine; and to the guidance provided by the office of the Surgeon General and the Committee on Military Nutrition Research. Although considerable strides have been made in improving the quality, variety, and acceptability of operational rations, rigorous efforts must continue to meet the changing food habits and expectations of the soldier, sailor, airman, and marine.


  • AR (Army Regulation) 40-25 1985. See U.S. Departments of the Army, the Navy, and the Air Force.
  • Brandler, P., and G.A. Darsch 1993. Food. Pp. 129–131 in McGraw-Hill Yearbook of Science and Technology. New York: McGraw-Hill, Inc.
  • Frederick II, King of Prussia 1966. Frederick the Great on the Art of War. New York: Free Press.
  • IOM (Institute of Medicine) 1991. The New Generation Survival Ration. A brief report of the Committee on Military Nutrition Research, Food and Nutrition Board. Washington, D.C.: National Academy Press.
  • QMC&S (U.S. Army Quartermaster Center and School) 1994. Executive Review of the Army Field Feeding System Future Concept Evaluation Program Data Collection Effort Field Trials. May, 1994. Ft. Lee, Va.: U.S. Quartermaster Center and School.
  • U.S. Departments of the Army, the Navy, and the Air Force 1985. Army Regulation 40-25/Naval Command Medical Instruction 10110.1/Air Force Regulation 160-95. "Nutrition Allowances, Standards, and Education." May 15. Washington, D.C.


ROBERT NESHEIM: Thank you very much. All I can say is that I was involved in World War II 50 years too early.

BARBARA ROLLS: Do soldiers have the ability to self-select the MREs that they want?

GERALD DARSCH: It depends on how fast you run! There are 12 meals in the case, and the soldiers know which number pertains to which meal. In some cases, foodservice personnel will just dump the case upside down. Peter Motrynczuk can answer this better than I, but if you are there quicker, you might get the meal you want before the last guy shows up.

PETER MOTRYNCZUK: Normally they will have a case open, and there are numbers that appear on meals. Because soldiers get to know what number is what, they will be selective if they have that opportunity. But most managers will not open another case until one case is completely emptied.



Gerald A. Darsch, U.S. Army Natick Research, Development and Engineering Center, Natick, MA 01760-5007


Packaged foods heat treated (e.q., 250¹F) under pressure (e.q., 15 psi) for sufficient time to inactivate food microorganisms. Examples of foods that require retort processing include low acid foods with sufficient moisture (e.g., entrees, vegetables, starches, and desserts) to support the growth of microorganisms.


The Soldier Enhancement Program is a U.S. Army program designed to accelerate the identification, field testing, and introduction of new items (with an emphasis on commercial off-the-shelf products) into the supply system to enhance the quality of life of soldiers.


Retort pouches serve as the primary food container. The pouches are flexible in nature and are constructed of a trilaminate material consisting of polyethylene as the food contact layer, a thin layer of aluminum foil, and polyester.

Copyright 1995 by the National Academy of Sciences. All rights reserved.
Bookshelf ID: NBK232441


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