USARIEM Researchers are Creating Better Food Rations for Warfighters
FORT DETRICK, Md. – It's a fact of life that Warfighters burn a lot of calories while on operations. In intense combat scenarios, Warfighters can expend up to 6,000 calories a day. If they can't eat enough to replace the lost calories, their bodies will start to break down muscle to make up for the deficit. And when that happens, they risk entering a downward spiral that can ultimately lead to impaired reaction times, reduced mobility and longer periods of recovery from injury – all of which negatively impact readiness when the unit can least afford it.
The reality during operations is that Warfighters usually have little – if any – time to eat. Therefore, everything they consume has to provide the maximum amount of nutritional benefit. That's why researchers at the Medical Research and Development Command's Institute of Environmental Medicine have been conducting studies aimed at providing scientific evidence that informs new food rations designed to not only satisfy a Warfighter's appetite, but also to prevent their muscles from being broken down for fuel.
"Amino acids are the part of dietary protein that helps build muscle," explains Dr. Jess Gwin, a research physiologist with USARIEM's Military Nutrition Division. "From a nutrition perspective, we're particularly interested in how energy deficits impact a Warfighter's ability to maintain their muscle, and whether increasing amino acid intake can help with that."
For several years, a team of researchers led by Gwin and her colleague, nutrition physiologist Dr. Emily Howard, have been conducting studies and field experiments to better understand how combat rations enriched with essential amino acids, commonly referred to as EAA, can improve the body's ability to build muscle during periods when Warfighters are not able to get enough food. The team has been carrying on work first undertaken by division colleagues nearly 15 years ago.
"Protein is only one piece of the puzzle," says Gwin. "We hope to develop ration products that complement each other and become like tools in the toolbox, which Service Members can combine to get the right balance of nutrients and hydration to meet their energy consumption needs and stay healthy."
Their first study, led by Gwin, followed a group of 19 Service Members through periods of controlled diet-induced energy deficits and intensive resistance exercise tests separated by a two-week cool-down period. At the end of each period of reduced calorie intake, they consumed a whey beverage with a higher concentration of EAA. Gwin found that study participants who ingested higher-than-normal amounts of EAA following exercise experienced a measurable increase in protein synthesis and a decrease in protein breakdown, resulting in a better total body protein balance.
Their next study built on those results by testing their hypothesis that changes in the body's net protein balance were associated with concentrations of EAA circulating in the bloodstream. The study followed a group of 10 volunteers through a similar regimen, this time comparing the results of consuming a whey protein beverage enhanced with EAA, a standard whey protein drink and a standard MRE entrée. Instead of resistance exercises, participants engaged in trap bar deadlifts and treadmill weighted ruck marches. The study results confirmed their hypothesis, which helped them better understand how the process works, but it was unclear whether offering EAA with other sources of nutrients, such as carbohydrates, provided greater benefit to supporting muscle synthesis. To answer those questions, Gwin conducted a third study that looked at how the body responds to an increase in EAA-enriched protein during periods of rest, and whether that helps the body maintain sufficient energy to avoid turning to muscle tissue to make up for the deficit. They found that the EAA-enhanced protein worked better than EAA-enhanced carbohydrates.
Having demonstrated those two findings, it was now time for Gwin and Howard to put them to the test in real-world conditions. Whereas the first three studies took place under controlled laboratory conditions, this test would take place in the remote, austere mountain environment of northern Norway, near the Russian border, during an eight-day cold-weather training exercise conducted by Norwegian Soldiers. Howard orchestrated USARIEM's participation, which presented formidable logistical challenges during the tail-end of the coronavirus pandemic. Howard led a team of 16 researchers who teamed up with representatives from the Norwegian Defense Research Establishment – with whom USARIEM has partnered on previous cold-weather studies – and the U.S. Army Combat Capabilities Development Command's Combat Feeding Division to test two protein- and calorie-enhanced ration bars as part of the Soldiers' regular rations.
Howard says that unlike previous exercises in Norway, the Soldiers in this experiment consumed sufficient food to prevent the onset of extreme energy deficit, which meant that the EAA did not provide significant additional benefit to their energy sustenance. Nonetheless, the field study provided a wealth of useful data and suggested the direction that future field studies could take.
"It really emphasized the point that minimizing energy deficits to a manageable level allows an individual to operate in harsh physical environments with minimal decrements," explains Howard. "Dr. Gwin and I are very interested in revisiting the EAA product in a field scenario where individuals are actually in a more severe energy deficit, so we may see the effects more clearly."
Gwin agrees. "This series of projects was highly informative, and we are excited to both continue addressing knowledge gaps while also celebrating associated prototype ration foods moving closer to fielding," she says.