Research report | Comparative Field Evaluation of the In-service and Prototype Modular Mission Adaptive Combat Ration Packs
Soldiers rarely consume all the food components issued in combat ration packs (CRP), compromising the adequacy of nutrient intake and the physical and cognitive performance of combatants. Mission adaptive (MA) nutrition—providing soldiers with optimal energy and nutrients when Army operates in contemporary environments and with changing demands—is thought to mitigate risk to performance. In a side-by-side comparison with in-service CRP, a nutrient optimised modular MA CRP design was fielded with dismounted infantry personnel to assess fitness-for-purpose and utilisation over a 6–day use period. Inadequate energy and nutrient intakes were identified as a result of the field trial. A detailed understanding of combatant energy expenditure, current and future risks to health and well-being and performance targets is required to optimise the design and provide a proof of concept. Further product development, potentially including formulated, energy-dense, and commercial-off-the-shelf components, is required to rectify the inadequate delivery of nutrients. Successful implementation of a MA CRP design will require training, education, policy and procedure, and interactive tools for verification of learning, validation of desirable behaviour and realisation of benefits. To provide a proof of concept, further trials are required to assess performance in various operational environments over longer use periods of up to 30 days.
Soldiers think and fight better when they are properly fed. However, they rarely consume all the food components issued in combat ration packs (CRP)—often as a result of ‘field stripping’ to mitigate for operational tempo and environmental constraints when deployed, or simply because they don’t like the food. Due to the combined effects of soldiers discarding food components and the poor stability of some vitamins during storage, the adequacy of nutrient intake from CRP during operations can be compromised. Associated with inadequate nutrient intake is the risk of decreased physical and cognitive performance. This has raised concerns about the suitability of the current CRP in the expanded range of Australian Defence Force operations. It is suggested that the problems identified above are interrelated and may be ameliorated through improvements to the configuration of CRP.
The Army Modernisation Plan 2015 has identified the requirement for mission adaptive (MA) nutrition. Mission adaptive nutrition aims to provide soldiers with optimal energy and nutrients when Army operates in contemporary environments and with changing demands. The ability to tailor the rations carried by combatants has the potential to make a critical contribution to combatant performance. Under an Army Headquarters (AHQ) Trial Directive the Defence Science and Technology (DST) Group is conducting research to design, produce and evaluate the use of modular rations in Defence use environments. The end state will enable and support Army combatants and combat support personnel to out-think, outperform and outlast a lethal, agile and adaptable adversary—providing the best nutrition and supplementation for enhanced cognitive and physical performance throughout enduring operations in complex and ambiguous environments.
A modular MA CRP design has been developed that delivers to energy, nutrition and other fit–for–purpose requirements specified in the CRP User Requirement (CRP UR). The MA CRP could potentially replace both current one-person, one-day CRPs, i.e. the Combat Ration One Man (CR1M) and Patrol Ration One Man.
A field trial was conducted to evaluate a prototype MA CRP assembled solely from in-service components and delivering energy and nutrients commensurate with activity category (AC) 3 requirements (energy expenditure of 16 MJ/day). This study was conducted in a side-by-side comparison with the CR1M assembled in FY15/16. Energy and nutrient content requirements for both CRP designs were similar and as assembled met the majority of the AC 3 Military Recommended Dietary Intakes (MRDI). Further developmental work, potentially including formulated, energy-dense, and commercial-off-the-shelf (COTS) components, is required. COTS components including sport/energy gels, jerky, trail mix, high protein and/or carbohydrate bars could reduce the instance of inadequate nutrition being delivered. Future configurations need to provide less CHO with a commensurate increase in protein and fat. Small increases in dietary fibre should also be targeted.
Inadequate energy and nutrient intakes were identified as a result of the field trial. The average calculated daily energy expenditure (EE) of users during the trial (19±2 MJ/day) was above the level of energy provided by the CRP. The average energy intake for users of the MA CRP was 7.9 MJ/day during a 6–day period. Those consuming the CR1M averaged 8.7 MJ/day. Intakes of protein, carbohydrate, dietary fibre, vitamins A, B6 and E, and minerals (calcium, copper, iodine, magnesium, manganese and potassium) were observed to be significantly inadequate. Additionally a significant excess of sodium intake was also identified.
Longer period studies are necessary to evaluate CRP acceptance and consumption patterns over enduring periods. Short-term studies of CRP use are limited in their ability to recognise and report patterns in consumer behaviour. These patterns may be influenced by mindsets such as ‘it’s only for a short period, I’ll go without now, and feed-up when I return’, ease of access to ‘jack rations’ and ability to swap with other combatants. Longer term studies are required to assess the potential exposure to nutrient inadequacies and inform the requirements for health, well-being and nutrition recovery programs.
To progress the modular MA CRP trials, DST Group recommends AHQ:
- review the reported EE for military tasks in ‘ADF Nutrients for the 21st Century’ for relevance to today’s and future operational missions and tasks in contemporary environments. The review should include consideration of changes in load carriage, operational tempo, duration, location and climate
- conduct a comparative study applying doubly-labelled water and/or indirect calorimetry methods for EE with non-invasive techniques/unobtrusive devices that estimate EE during military-related activities. The aim being to make an informed decision on appropriate devices for field use applications and calculation of correction factors for such non-invasive techniques
- informed by the above, identify and specify the appropriate energy and nutrition required by combatants to adequately maintain health and well-being, and optimise their performance
- better understand and articulate the requirements of users in contemporary operational environments by conducting further field use trials that scope activities: o where combatants require energy and nutrients commensurate with AC 2 and AC 4
- conducted in use environments other than hot climate
- of longer duration (up to 30 days).
- consider the inclusion of the following additional outputs in the current Trial Directive and associated task documentation: o training and education packages for Commanding Officers, combatants and Combat Soldier Support personnel
- policy and procedure for implementation, use, monitoring and control of MA CRP
- interactive tools for verification of learning, validation of desirable behaviour and realisation of benefits.
These outputs would enable the ADF to demonstrate appropriate CRP use, evaluate and where necessary change consumer behaviour through reinforcement of learning
- evaluate current field feeding practices in order to identify the hazards and mitigation strategies to reduce the risks to health when sustaining on CRP
- assess combatant’s tolerance for CRP load burden, within the broader scope of the soldier combat ensemble load. Measure and compare the maximum, the actual and the desired CRP load burden users are prepared to carry during an expanded range of operations over enduring periods. This will confirm or refine the appropriateness of the current weight target of <1600 g
- include assessment of body weight and composition to understand the prevalence and significance of change to individuals’ health status when subsisting on CRP for long periods
- better understand what function and level of performance food has in maintaining and potentially enhancing cognitive performance. Outcomes from this work should be used to influence CRP design in both product selection and eating behaviour.
In considering future configurations of the modular MA CRP, DST Group recommends:
- component selection focus on:
- achieving functional and performance targets—include fortified components, offer variety and convenience (reduce impost on time, effort and equipment), hygienic in delivery
- delivering adequate energy and nutrition
- promoting high level consumption
- reducing load burden—include energy dense and nutrient rich components (particularly those used in the meals modules). Product concepts including the combat food bar, COTS meal-in-a-bar and freeze dried products should be introduced to the MA CRP menu configuration
- well-consumed, highly accepted and nutritionally ‘valuable’ components be retained. Further, the weight of these popular items could be increased, and in doing so potentially increase the likelihood of improved nutrient intakes and a cost benefit—reducing the number of components required to ensure the MRDI requirements are met
- the value and continued use of unpopular, poorly consumed ‘at risk’ components (such as those more vulnerable to cross-contamination) be assessed. If continued use is justified, component improvement, COTS substitution and use of alternative
- packaging are all strategies to improve utility of such components in military use environments
- removing rigid cans and aluminium tubes used to package CRP components
- introducing single use drink pouches for drink powders including sports drinks and ‘protein shakes’
- introducing wet wipes and hand sanitiser in a potential field hygiene pack.
To improve the design and use of in-service CR1M, DST Group recommends:
- the energy content of CR1M be reduced to 16 MJ. This is 1.8 MJ lower than the current average energy content
- the energy and nutrient non–compliances identified in CR1M be addressed. This includes reducing saturated fat, CHO (particularly sugar) and sodium, while increasing micronutrient content, particularly vitamins B2, B6 and E and copper. Actions could include:
- removing discretionary salt (reducing sodium by ~760 mg/day)
- halving the salt content in those components currently contributing significant amounts to the daily provisioning (including retort meals, soup mixes and noodles condiments)
- introducing low level (~20% MRDI) fortification of the suite of vitamins in key highly consumed CRP components including long life bread, wet (retort) meals, cheese, fruit, cereal and meat-based bars and drink powders
- introducing product concepts, not currently included in CRP, which combatants are regularly using. This should include trail mixes, jerky and food bars.
- the ‘brew kit’ be re-configured with a focus on convenience and waste minimisation to justify continued inclusion. Coffee/sugar/milk or tea/sugar/milk could be consolidated as single serve, pre-mixed, hot drink sachets.
To further understand the ability of CRP to provide the required nutrients, evaluate compliance of the following:
- vitamins B12, D, K, folate and pantothenic acid