Emerging Technologies in Nutrition Research for the Military: Overview of the Issues
James A. Vogel1
Optimal garrison nutrition along with the use of nutritional interventions to maintain or enhance performance under demanding operational circumstances are important to the Armed Forces and are key features of the U.S. Department of Defense's Military Nutrition Research Program. While much of the program is applied in nature and field-trial oriented, the total program, including both intramural and extramural components, demands that the latest innovative technologies be utilized in order to find answers to highly complex issues that now confront the nutrition of today's military service member.
The Military Nutrition Research Program is broad in its scope as it addresses not only optimal nutritional intake and nutritional status of the service member, but also the issues of how nutritional status affects both physical and cognitive performance, as well as health issues that indirectly or directly affect
performance. The end result is a need for military nutrition researchers to utilize the latest available technologies in addressing a wide variety of applications to nutrition research, which is the focus of this workshop. This chapter describes the Military Nutrition Research Program in order to identify some of the technologies that are needed to support it.
ORGANIZATION OF THE MILITARY NUTRITION RESEARCH PROGRAM
The Army Surgeon General is responsible to the Department of Defense to conduct research on nutrition and related medical and performance issues for all services. This responsibility pertains both to operational rations and garrison feeding. The program is executed by the Military Nutrition Division (currently the Military Nutrition and Biochemical Division) at the U.S. Army Research Institute of Environmental Medicine at Natick, Mass., and comes under the management of the U.S. Army Medical Research and Materiel Command's Military Operational Medicine Directorate. The companion program for the formulation of operational rations, along with their packaging, field preparation, and delivery, is the responsibility of the Natick Research, Development and Engineering Center's Survivability Directorate under the U.S. Army Soldier Systems Command, also located at Natick, Mass. The requirements of these two research programs are identified by the Food Nutrition Research and Engineering Board, Office of the Secretary of Defense for Science and Technology.
PURPOSE OF THE PROGRAM
The Military Nutrition Research Program exists as an established Army Science and Technology Objective and is composed of four areas: (1) development of nutritional strategies to sustain and enhance military performance in operational environments; (2) evaluation of operational rations and field feeding systems for effects on nutritional status, health, and performance; (3) establishment of nutritional standards for operational rations; and (4) determination of nutritional status of military populations and improvement of garrison diets. Each of these program areas is described briefly.
Development of Nutritional Strategies
Nutritional strategies refer to steps taken, above and beyond providing for a well-balanced and nutritious garrison diet, to provide an enhanced capability to perform in hostile climatic or operational environments common to the Armed Forces. When a service member is subjected to the multiple stressors of these environments, such as caloric deprivation, sleep loss, and high work load,
nutrients may become depleted, or their supplementation above usual levels may give a performance advantage in these unique settings. Research in this area is currently divided into three subtopics: (1) performance-enhancing ration components, (2) dietary treatments to counteract immunosuppression, and (3) dietary interventions to meet special requirements.
Performance-Enhancing Ration Components
The concept of adding specific nutrients to an already ''optimal" field diet to maintain or enhance performance arose from the Special Operations Command's requirements for simple and safe ways to meet high performance requirements in demanding missions. These added nutrients include potential nutrient ergogenic aids as well as food additives that would counteract sleep loss and maintain alertness and cognitive function under severe stress. This program encompasses research ranging from basic studies on nutrient substrates for brain neurotransmitters to the actual field evaluation in simulated operational settings of proposed ration additives.
Two compounds proven as performance enhancers that can be incorporated within ration items are caffeine and extra amounts of carbohydrates. Caffeine is a proven ergogenic aid (Graham et al., 1994) and is also beneficial in maintaining alertness during sleep deprivation (Lieberman, 1992). Carbohydrate supplementation has proven beneficial for intense, sustained physical performance (Coyle, 1991). In both cases, further research is needed to determine optimal regimens customized to particular military tasks or missions.
Tyrosine (Banderet and Lieberman, 1989) and tryptophan (Segura and Ventura, 1988) are amino acid precursors for neurotransmitters that may aid in sustaining mental function under severe operational stress. Further research is needed to confirm their effect on humans in various militarily relevant environments.
Examples of additional nutrient-type ergogenic additives of recent interest to the military include choline (Wurtman and Lewis, 1991) and creatine (Harris et al., 1992). For the most part, these components have yet to be proven to have practical use in human performance settings.
Dietary Treatments to Counteract Immunosuppression
Recent research carried out as part of the Military Nutrition Research Program has shown that soldiers under the multiple stresses of simulated combat demonstrate an immunosuppressive state that places them at increased risk for infection. Original research on this topic carried out in Army Ranger trainees (Moore et al., 1992) focused on significant caloric deprivation as the primary stress leading to the immunosuppression. Subsequent research (Shippee et al., 1994) with lesser degrees of caloric deprivation suggests that other stressors that
also are present—sleep deprivation, heavy work loads, and behavioral stress—may also be implicated. These findings have led to a search for nutritional countermeasures for immunosuppression. Glutamine, choline, antioxidant mixtures, and tyrosine have been studied or are currently under consideration for this purpose.
Dietary Interventions to Meet Special Requirements
In addition to supplementing diets with specific nutrients to enhance performance or correct performance deficits, the use of dietary manipulation also presents itself as a potential strategy to exploit. Topics that have been studied include adjusting the timing of food ingestion, using nutrition education to meet the particular needs of highly active personnel at high levels of performance, and customizing operational ration components to the individual service member and to his or her specific mission requirement. The latter concept stems from interest by the Special Forces in meeting the extreme demands of the individual and unique requirements of certain Special Forces missions.
Evaluation of Operational Rations and Field Feeding Systems
A major component of the Military Nutrition Research Program is the evaluation of the nutritional adequacy of newly developed operational rations to ensure that they meet the health and performance standards of military personnel under all operational conditions. Each new ration item or ration delivery system is tested under realistic field-operating environments to determine if it meets the goals of optimal nutritional delivery to service members in the field. Under this program the Meal, Ready-to-Eat, multi-serving tray packs, and the total field feeding system (USACDEC/USARIEM, 1986) have been tested under various operational and climatic conditions.
This research also has included the assessment of specialty operational rations such as the New Generation Survival Ration (Jones et al., 1992); the Ration, Lightweight (Askew et al., 1987); Long Life Ration Packet (King et al., 1992); and Ration, Cold Weather (Engell et al., 1987). The observed reduction in caloric consumption while eating operational rations also has been studied (Thomas et al., 1995).
Establishment of Nutritional Standards
Although the Military Recommended Dietary Allowances (MRDAs) are now generally well established, special or unique issues that require continued research still arise, particularly in relation to operational feeding. Some examples include: (1) the status of iron nutriture and the need for iron
supplementation for female soliders, (2) the composition and use of oral hydration (electrolyte-glucose) drinks for hot weather and heavy exercise, (3) nutrient requirements and delivery while wearing encapsulated protective clothing, and (4) energy requirements of various operational missions.
Determination of Nutritional Status of Military Populations
Another important component of the Military Nutrition Research Program is the periodic evaluation of the adequacy of military feeding, both in the field and in garrison, by the periodic assessment of the nutritional status of military populations and their dietary intakes. A major thrust of this program is to reduce the overall intake of total fat, cholesterol, and salt. Research in this area includes education (Torri and Baker-Fulco, 1992), menu assessments (Szeto et al., 1987), and menu modification to bring about these changes (Baker-Fulco et al., 1994).
Recent emphasis in this area has centered on nutritional status and dietary intake of women in the Army with particular focus on women entering the service and during initial entry training (King et al., 1994). Specific populations also are studied when questions arise regarding their intake; these include military academy cadets (Klicka et al., 1993), Ranger trainees (Moore et al., 1992; Shippee et al., 1994), and Special Forces candidates.
OTHER NUTRITIONALLY RELATED RESEARCH
Several areas of research are being conducted under the auspices of other military research initiatives, but they apply directly to military nutrition. One of these is body composition investigations. This research includes the development of body weight-for-height standards, body fat standards, and methodology for field estimation of body fat for the Army Weight/Body Fat Program (AR 600-9, 1986), and methodology for field estimation of how body fat and muscle mass relate to physical performance (Vogel and Friedl, 1992). Other research areas include the methodology of measuring caloric expenditure in the field and the relation of injuries and bone density to dietary intake.
The scope of military nutrition research has broadened considerably in recent years, well beyond that of nutritional status, requirements, and deficiencies and their impact on health. Modern warfare presents many new and unique challenges to feeding the fighting service member to maintain or enhance both health and performance. It is the latter factor—a focus on performance—that now frames much of military nutrition research.
The inability to maintain adequate nutritional intake at all times during combat, or the need to utilize nutrition to elicit supranormal performance in
special operations, challenges the military nutrition researcher to seek new solutions to complex problems. The broad and varied Military Nutrition Research Program outlined in this chapter requires the best technology that can be assembled. It is displayed in the subsequent chapters.
AR (Army Regulation) 600-9 1986 See U.S. Department of the Army, 1986.
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