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All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Extension of Space Food Shelf Life Through Hurdle Approach

The processed and prepackaged space food system is the main source of crew nutrition, and hence central to astronaut health and performance. Unfortunately, space food quality and nutrition degrade to unacceptable levels in two to three years with current food stabilization technologies. Future exploration missions will require a food system that remains safe, acceptable and nutritious through five years of storage within vehicle resource constraints. The potential of stabilization technologies (alternative storage temperatures, processing, formulation, ingredient source, packaging, and preparation procedures), when combined in hurdle approach, to mitigate quality and nutritional degradation is being assessed. Sixteen representative foods from the International Space Station food system were chosen for production and analysis and will be evaluated initially and at one, three, and five years with potential for analysis at seven years if necessary. Analysis includes changes in color, texture, nutrition, sensory quality, and rehydration ratio when applicable. The food samples will be stored at -20 C, 4 C, and 21 C. Select food samples will also be evaluated at -80 C to determine the impacts of ultra-cold storage after one and five years. Packaging film barrier properties and mechanical integrity will be assessed before and after processing and storage. At the study conclusion, if tested hurdles are adequate, formulation, processing, and storage combinations will be uniquely identified for processed food matrices to achieve a five-year shelf life. This study will provide one of the most comprehensive investigations of long duration food stability ever completed, and the achievement of extended food system stability will have profound impacts to health and performance for spaceflight crews and for relief efforts and military applications on Earth.

Cooper, M. R.↗
NASA NTRS1999

Nutrition and Foods as Related to Space Flight

U.S. space food development began with highly engineered foods that met rigid requirements imposed by the spacecraft design and short mission durations of the Mercury and Gemini programs. The lack of adequate bathroom facilities and limited food storage capacity promoted the development of low fiber diets to reduce fecal output. As missions lengthened, space food systems evolved, with the most basic design consideration always being the method of water supply. On the Apollo spacecraft, where water was abundant as a byproduct of fuel cell electricity generation, dehydrated food was used extensively. Such food has little advantage when water has to be transported to space to rehydrate it; therefore, more complex food systems were planned for Skylab, which used solar panels rather than fuel cells for electricity generation. The Skylab food system, the most advanced used in space to date, included freezers and refrigerators, increasing the palatability, variety, and nutritional value of the diet. On the Space Shuttle, power and weight constraints precluded the use of freezers, refrigerators, and microwave ovens. The availability of fuel cell by-product water was conducive to a shelf-stable food system with approximately half of the food dehydrated and the remainder made up of thermostabilized, irradiated, and intermediate-moisture foods.

Lane, Helen W.↗
NASA NTRS2016

Meal Replacement Mass Reduction and Integration Acceptability Study

NASA, in planning for long duration missions, has an imperative to provide a food system with the necessary nutrition, acceptability, and safety to ensure sustainment of crew health and performance. The Orion Multi-Purpose Crew Vehicle (MPCV) and future exploration missions are mass constrained; therefore we are challenged to reduce the mass of the food system by 10% while maintaining safety, nutrition, and acceptability for exploration missions. Food bars have previously been used to supplement meals in the Skylab food system, indicating that regular consumption of bars will be acceptable. However, commercially available products do not meet the requirements for a full meal replacement in the spaceflight food system. The purpose of this task is to develop a variety of nutritionally balanced breakfast replacement bars, which meet spaceflight nutritional, microbiological, sensorial, and shelf-life requirements, while enabling a 10% food mass savings. To date, six nutrient-dense meal replacement bars have been developed, using both traditional methods of compression as well as novel ultrasonic compression technologies developed by Creative Resonance Inc. (Phoenix, AZ). All bars will be prioritized based on acceptability and the four top candidates will be evaluated in the Human Exploration Research Analog (HERA) to assess the frequency with which actual meal replacement options may be implemented. Specifically, overall impact to mood, satiety, dietary discomfort, and satisfaction with food will be analyzed to inform successful implementation strategies. In addition, these bars will be evaluated based on final product sensory acceptability, nutritional stability, qualitative stability of analytical measurements (i.e. water activity and texture), and microbiological compliance over two years of storage at room temperature and potential temperature abuse conditions to predict long-term acceptability. It is expected that this work will enable a successful meal replacement strategy to be implemented that maintains crew food consumption and health, while informing exploration missions with appropriate mass savings expectations.

Sirmons, T.↗
NASA NTRS2024

Enhancing Global Food Security: Opportunities for the American Meteorological Society

Food security is a key pillar of environmental security yet remains one of the world’s greatest challenges. Its obverse, food insecurity, negatively impacts health and well-being, drives mass migration, and undermines national security and global sustainable development. Ensuring food security is a delicate balance of myriad concerns within the atmospheric and Earth sciences, agronomy and agriculture engineering, social sciences, economics, monitoring, and policymaking. A Food Security Presidential Session at the American Meteorological Society’s (AMS) 2022 Annual Meeting brought together experts across disciplines to tackle issues at the nexus of weather, climate, and food security. The starkest takeaway was the realization that, despite its importance and clear roles for the atmospheric and climate sciences, food security has not been a focus for the AMS community. The aim of this paper is to build on the perspectives shared by this expert panel and to identify overlapping issues and key points of intersection between the food-security community and AMS. We examine 1) the interactions between weather, climate, and the food system and how they influence food security; 2) the time and spatial scales of food security decision support that match weather and climate phenomena; 3) the role of both providers and users of information as well as decision-makers in improving research to operations for food security; and 4) the opportunities for the AMS community to address food security. We conclude that, moving forward, the AMS community is well-positioned to scale up its engagement across the global food system to address existing scientific needs and technology gaps to improve global food security.

Food security↗
NASA NTRSDate not supplied

Bionutrients-1: Utilizing Genomics and Transcriptomics to Assess the Reliability of Microorganisms for In Situ Nutrient Production on Long Duration Missions

The resupply of current long-duration crewed missions to the ISS relies on ground-launched supplies. As NASA looks toward Mars, ground-based resupply will no longer be an option. Critical nutrients, including vitamin C, vitamin K, folate, and thiamin, degrade during long-term storage, and regular consumption of these nutrients is essential for astronaut health. Another challenge of current food systems is the difficulty of consuming sufficient calories when subsisting on the limited flavors of freeze-dried food, which can lead to weight loss. The inclusion of microorganism-based food systems could alleviate both concerns. For example, the fermentation of rehydrated milk into yogurt with microorganisms genetically incorporating genes to produce critical vitamins would allow for both in situ production of nutrients and a fresh food product with additional flavor profiles. In comparison to plant food production, microorganisms require less flight infrastructure. The BioNutrients-1 mission is demonstrating viability of microbial fermentation food production in microgravity and testing the reliability of this approach for long-duration missions lacking resupply. While the BioNutrients-1 mission includes the collection of multiple phenotypic measurements, this status update will focus on the processing of samples for genomics and transcriptomics analyses as well as the planned analysis pipelines. First, the BioNutrients-1 mission seeks to identify microorganisms capable of surviving long-duration storage at ambient temperatures while maintaining genetic fidelity. To achieve this, nine commonly employed microbial species were stored at ambient temperatures in Stasis Packs on the ISS for five years. The viability and mutation rates will be measured at multiple time points for both flown and ground control samples. From an omics perspective, the changes in the bulk rates of point mutations and genetic rearrangements across the Stasis Pack species during the five years of storage will be determined, providing valuable insights into the potential of these microorganisms for long-duration space missions. Second, the BioNutrients-1 mission is characterizing the impact of microgravity on fermentation. Two strains of the yeast Saccharomyces cerevisiae, each encoding antioxidants (β-carotene or zeaxanthin) were flown to ISS for storage and fermentation within simplified bioreactors (Production Packs). The impact of microgravity on the expression of the antioxidant production genes and general metabolic genes will be determined using RNA sequencing. Ultimately, the transcriptome data will be compared to phenotypic measurements, such as the antioxidant yield, end-state biomass, and the production of EtOH, to determine the impacts of microgravity and long-term storage on microbial fermentation. The findings from this research will be instrumental in understanding the challenges and opportunities of microorganism-based food systems in space missions.

BioNutrients↗
NASA NTRS2017

Future Food Production System Development Pulling from Space Biology Crop Growth Testing in Veggie

Preliminary crop testing using Veggie indicates the environmental conditions provided by the ISS are generally suitable for food crop production. When plant samples were returned to Earth for analysis, their levels of nutrients were comparable to Earth-grown ground controls. Veggie-grown produce food safety microbiology analysis indicated that space-grown crops are safe to consume. Produce sanitizing wipes were used on-orbit to further reduce risk of foodborne illness. Validation growth tests indicated abiotic challenges of insufficient or excess fluid delivery, potentially reduced air flow leading to excess water, elevated CO2 leading to physiological responses, and microorganisms that became opportunistic pathogens. As NASA works to develop future space food production, several areas of research to define these systems pull from the Veggie technology validation tests. Research into effective, reusable water delivery and water recovery methods for future food production systems arises from abiotic challenges observed. Additionally, impacts of elevated CO2 and refinement of fertilizer and light recipes for crops needs to be assessed. Biotic pulls include methods or technologies to effectively sanitize produce with few consumables and low inputs; work to understand the phytomicrobiome and potentially use it to protect crops or enhance growth; selection of crops with high harvest index and desirable flavors for supplemental nutrition; crops that provide psychosocial benefits, and custom space crop development. Planning for future food production in a deep space gateway or a deep space transit vehicle requires methods of handling and storing seeds, and ensuring space seeds are free of contaminants and long-lived. Space food production systems may require mechanization and autonomous operation, with preliminary testing initiated to identify operations and capabilities that are candidates for automation. Food production design is also pulling from Veggie logistics lessons, as we learn about growing at different scales and move toward developing systems that require less launch mass. Veggie will be used as a test bed for novel food production technologies. Veggie is a relatively simple precursor food production system but the knowledge gained from space biology validation tests in Veggie will have far reaching repercussions on future exploration food production.

Veggie↗
NASA NTRS2017

Future Food Production System Development Pulling From Space Biology Crop Growth Testing in Veggie

Preliminary crop testing using Veggie indicates the environmental conditions provided by the ISS are generally suitable for food crop production. When plant samples were returned to Earth for analysis, their levels of nutrients were comparable to Earth-grown ground controls. Veggie-grown produce food safety microbiology analysis indicated that space-grown crops are safe to consume. Produce sanitizing wipes were used on-orbit to further reduce risk of foodborne illness. Validation growth tests indicated abiotic challenges of insufficient or excess fluid delivery, potentially reduced air flow leading to excess water, elevated CO2 leading to physiological responses, and microorganisms that became opportunistic pathogens. As NASA works to develop future space food production, several areas of research to define these systems pull from the Veggie technology validation tests. Research into effective, reusable water delivery and water recovery methods for future food production systems arises from abiotic challenges observed. Additionally, impacts of elevated CO2 and refinement of fertilizer and light recipes for crops needs to be assessed. Biotic pulls include methods or technologies to effectively sanitize produce with few consumables and low inputs; work to understand the phytomicrobiome and potentially use it to protect crops or enhance growth; selection of crops with high harvest index and desirable flavors for supplemental nutrition; crops that provide psychosocial benefits, and custom space crop development. Planning for future food production in a deep space gateway or a deep space transit vehicle requires methods of handling and storing seeds, and ensuring space seeds are free of contaminants and long-lived. Space food production systems may require mechanization and autonomous operation, with preliminary testing initiated to identify operations and capabilities that are candidates for automation. Food production design is also pulling from Veggie logistics lessons, as we learn about growing at different scales and move toward developing systems that require less launch mass. Veggie will be used as a test bed for novel food production technologies. Veggie is a relatively simple precursor food production system but the knowledge gained from space biology validation tests in Veggie will have far reaching repercussions on future exploration food production. This work is supported by NASA.

Plants↗
NASA NTRS2010

Non-Microgravity Provocations to Crew - Food

This slide presentation reviews the importance of food for long term space exploration missions. The Goals and objectives of the NASA food system is to develop a food system that is safe, nutritious, acceptable and efficiently balances appropriate vehicle resources: volume, mass, waste, water, power, cooling, air, and crew time. The importance of not only the nutrition, but the socialization of meals is also discussed.

Perchonok, Michele H.↗
NASA NTRS2017

The Stability of Bioactive Compounds in Spaceflight Foods

The status and stability of bioactive compounds in the processed and shelf-stable spaceflight food system have not previously been investigated though the presence of such compounds in aged space foods could have health significance for crews on long duration exploration missions. Over forty foods - either existing International Space Station (ISS) food provisioning items, newly developed foods for spaceflight, or commercially-available ready-to-eat foods - that were predicted to have a relatively high concentrations of one or more bioactive compounds (lycopene, lutein, omega-3 fatty acids, phenolics, sterols, and/or flavonoids) were selected for the study. Food samples were sent overnight to the Food Composition Laboratory of the Linus Pauling Institute at Oregon State University (Corvallis, OR) for bioactive compound analysis. Three packages of each product were blended together for the analysis to reduce package-to-package variability. All ISS food items and commercial foods were analyzed initially and after 12 and 24 months of 21degC storage. Food development occurred in a staggered fashion, so data collection for the newly developed foods continues. Lastly, sensory evaluation and additional temperature storage data (4degC, 35degC) for select foods were collected to establish additional stability parameters. Efficacious concentrations of lycopene, lutein, and omega-3 fatty acids were measured in limited spaceflight foods; two grams of sterols a day may be difficult to achieve with the current space diet. Total polyphenol delivery appears stable and adequate, but individual phenolic compounds vary in stability and were not specifically evaluated in this study. The data suggests that some bioactive compounds, like lycopene and lutein, degrade and then plateau at some equilibrium concentration. The anthocyanin stability appears to be related to storage temperature and food matrix, and lutein stability in leafy vegetables may be impacted by storage temperature. Because of the limited number of foods with high concentrations of the bioactive compounds, additional menu variety, formulation optimization, and reduced temperature storage will be required to ensure delivery of several bioactive compounds in the space food system. Validation of stability to five years will enable provisioning of these functional foods within the space food system for a mission to Mars.

Cooper, M. R.↗
NASA NTRS1974

Space shuttle/food system study. Volume 2, Appendix A: Active heating system-screening analysis. Appendix B: Reconstituted food heating techniques analysis

Technical data are presented which were used to evaluate active heating methods to be incorporated into the space shuttle food system design, and also to evaluate the relative merits and penalties associated with various approaches to the heating of rehydrated food during space flight. Equipment heating candidates were subject to a preliminary screening performed by a selection rationale process which considered the following parameters; (1) gravitational effect; (2) safety; (3) operability; (4) system compatibility; (5) serviceability; (6) crew acceptability; (7) crew time; (8) development risk; and (9) operating cost. A hot air oven, electrically heated food tray, and microwave oven were selected for further consideration and analysis. Passive, semi-active, and active food preparation approaches were also studied in an effort to determine the optimum method for heating rehydrated food. Potential complexity, cost, vehicle impact penalties, and palatability were considered in the analysis. A summary of the study results is provided along with cost estimates for each of the potential sytems

Source record↗
NASA NTRS2010

Comparison of Traditional and Innovative Techniques to Solve Technical Challenges

Although NASA has an adequate food system for current missions, research is required to accommodate new requirements for future NASA exploration missions. The Inadequate Food System risk reflects the need to develop requirements and technologies that will enable NASA to provide the crew with a safe, nutritious and acceptable food system while effectively balancing appropriate resources such as mass, volume, and crew time in exploratory missions. As we go deeper into space or spend more time on the International Space Station (ISS), there will be requirements for packaged food to be stored for 3 5 years. New food packaging technologies are needed that have adequate oxygen and water barrier properties to maintain the foods' quality over this extended shelf life. NASA has been unsuccessful in identify packaging materials that meet the necessary requirements when using several traditional routes including literature reviews, workshops, and internal shelf life studies on foods packaged in various packaging materials. Small Business Innovative Research grants were used for accelerating food packaging materials research with limited success. In order to accelerate the process, a theoretical challenge was submitted to InnoCentive resulting in a partial award. A similar food packaging challenge was submitted to Yet2.com and several potential commercial packaging material suppliers were identified that, at least partially, met the requirements. Comparisons and results of these challenges will be discussed.

Perchonok, Michele↗
NASA NTRS2020

Food Acceptability, Menu Fatigue, and Aversion on ISS Missions

The acceptability of the spaceflight food system has been linked to caloric intake and associated nutritional benefits. The diets of the United States Operating Segment crewmembers during a mission are restricted to 200 processed and prepackaged standard menu items supplemented with personal preference foods. ISS crew members have noted in debriefs that they would prefer more food variety for the length of the missions and they tire of certain foods over six months. It is possible that menu fatigue leads to decreases in acceptability and increased aversion to available foods, potentially contributing to the body mass loss often experienced by ISS crew. However, the impact of repeat food consumption on acceptability within the current spaceflight food system has not yet been systematically investigated. Limited variety and crew preferences within food categories may have more severe physical and behavioral health and performance consequences as mission duration increases. Characterizing the relationship between food acceptability and mission duration will contribute to defining requirements for an acceptable food system that will support crew health and performance on long duration missions.

Douglas, Grace L.↗
NASA NTRS2017

Meal Replacement Mass Reduction and Integration Acceptability Study

NASA, in planning for long-duration missions, has an imperative to provide a food system with the necessary nutrition, acceptability, and safety to ensure sustainment of crew health and performance. The Orion Multi-Purpose Crew Vehicle (MPCV) and future exploration missions are mass constrained; therefore the team is challenged to reduce the mass of the food system by 10% while maintaining product safety, nutrition, and acceptability. Commercially available products do not meet the nutritional requirements for a full meal replacement in the spaceflight food system, and it is currently unknown if daily meal replacements will impact crew food intake and psychosocial health over time. The purpose of this study was to develop a variety of nutritionally balanced breakfast replacement bars that meet spaceflight nutritional, microbiological, sensorial, and shelf-life requirements, while enabling a 10% savings in food mass. To date, six nutrient-dense meal replacement bars (approximately 700 calories per bar) have been developed, using traditional methods of compression as well as novel ultrasonic compression technologies developed by Creative Resonance Inc. (Phoenix, AZ). The four highest rated bars were evaluated in the Human Exploration Research Analog (HERA) to assess the frequency with which actual meal replacement options may be implemented. Specifically, overall impact of bars on mood, satiety, digestive discomfort, and satisfaction with food. These factors are currently being analyzed to inform successful implementation strategies where crew maintain adequate food intake. In addition, these bars are currently undergoing shelf-life testing to determine long-term sensory acceptability, nutritional stability, qualitative stability of analytical measurements (i.e. water activity and texture), and microbiological compliance over two years of storage at room temperature and potential temperature abuse conditions to predict long-term acceptability. It is expected that this work will enable a successful meal replacement strategy to be implemented that will maintain crew food consumption and health, while informing exploration missions with appropriate mass savings expectations.

Sirmons, T.↗
NASA NTRS2023

Structural Chokepoints Determine the Resilience of Agri-Food Supply Chains in the United States

The agricultural and food systems of the United States are critical for ensuring the stability of both domestic and global food systems. Thus, it is essential to understand the structural resilience of the country’s agri-food supply chains to a suite of threats. Here we employ complex network statistics to identify the spatially resolved structural chokepoints in the agri-food supply chains of the United States. We identify seven chokepoints at county scale: Riverside CA, San Bernardino CA, Los Angeles CA, Shelby TN, Maricopa AZ, San Diego CA and Cook IL; as well as seven chokepoints at freight analysis framework scale: Los Angeles–Long Beach CA, Chicago– Naperville IL, New York–New Jersey NJ, New York–New Jersey NY, Remainder of Texas, Remainder of Pennsylvania, and San Jose–San Francisco–Oakland CA. These structural chokepoints are generally consistent through time (2007, 2012, 2017), particularly for processed food commodities. This study improves our understanding of agri-food supply-chain security and may aid policies aimed at enhancing its resilience.

Agriculture↗
NASA NTRSDate not supplied

Precision Fermentation: Relieving the Crabtree Effect in S. cerevisiae through Genetic Engineering

Nutrient degradation in the current NASA pre-packaged food system poses significant challenges to crew health in missions beyond low earth orbit as certain vitamins and nutrients have been shown to degrade during extended storage, and resupply and fresh food items cannot be readily provided. BioNutrients(BN) uses synthetic biology in an effort to supplement the NASA food system by delivering in situ production of nutrients and therapeutics produced by genetically engineered microbes. One yeast S. cerevisiae strain utilized in BN is genetically modified to produce two types of antioxidants: zeaxanthin and β-carotene. Zeaxanthin is a non-provitamin A carotenoid and has been implicated in eye health and vision performance, and β-carotene is a provitamin A carotenoid. Microbial production of high-value nutrients can aid our understanding and address the issue of nutrient degradation and loss in the NASA food system. Although S. cerevisiae is an excellent candidate for a long shelf life, on-demand nutrient production system, its space applications are limited by the Crabtree effect where respiration is shut down in favor of fermentative metabolism when glucose is present in high concentrations, causing the release of unwanted ethanol. Current and likely future life support systems are negatively impacted by ethanol and ethanol release is strictly limited.To improve feasibility of using S. cerevisiae, we explored ways to reduce the Crabtree effect, thereby limiting its ethanol production. Specifically, we used CRISPR-cas9 to genetically modify various genes in this pathway

E Zaroff↗
NASA NTRSDate not supplied

Appetite and Food Intake During 11 Days of Mild Hypobaric Hypoxia

Introduction Reduced food consumption and loss of body mass and muscle mass have been observed during spaceflight. Hypoxic conditions that astronauts may encounter on exploration missions may further implicate satiety signals and dietary intake. Appetite, food intake, and satiety hormones were investigated under the conditions of mild hypoxia and high energy output during simulated extravehicular activity (EVA) to determine the adequacy of a mission relevant space food system to support energy balance and body composition. Methods Foods realistic to early Artemis missions was packed by meal for each subject for the 11-day test based on estimated energy requirements (EER) and estimated EVA caloric requirements. No hot water or food warmer was provided and only room temperature water was available to rehydrate food and beverages in-mission, mimicking plans for early Artemis missions. Measures included food records (pre-mission, in-mission); fasted body weight (pre-mission, in-mission); Dual-energy X-ray absorptiometry (DXA) (pre-mission, post-mission); subjective ratings and feedback of food acceptability, mealtime and meal preparation sufficiency, appetite, and nausea (in-mission); and circulating ghrelin and leptin concentration in fasted blood samples (pre-mission, in-mission: pre-post EVA). Results All subjects consumed fewer calories in-mission than predicted. On average, subjects consumed 341 calories less on EVA days compared to non-EVA days in-mission (p=0.0511). The total weight loss estimate from daily weight measurements (-1.1 kg, p=0.0028) is consistent with underconsumption and supported by DXA measurements (-1.3 kg total body mass, p=0.0123 and -1.6 kg fat mass, p=0.0016). In general, most foods that were consumed were given acceptable scores, but subject comments indicated that the most acceptable foods were those not intended to be heated. Comments also indicated that subjects found their favorite foods early in the mission and avoided the foods that they did not like throughout the mission. Habitability scores indicated that overall aspects of the food system were considered borderline or unacceptable over the length of this mission. Foods that caused gas were avoided pre-EVA to prevent discomfort during pressure changes. Average fruit and vegetable intake decreased during the mission, dropping from 4.8 servings/d pre-mission to 3.4 servings/d on non-EVA days in-mission (p=0.0872) and 2.3 servings on EVA days (p=0.0020). Fasting ghrelin concentrations tended to be lower pre-EVA and on non-EVA days when exposed to mild hypoxia compared to normoxic conditions pre-mission and post-EVA (p=0.0136). Fasting levels of leptin did not change. Discussion Food intake was reduced in-mission, resulting in a caloric deficit and weight loss for most subjects. Crew food and appetite ratings and comments indicated this was due to a combination of food choices, lack of preference, lack of preparation capability, lack of time for meal preparation, consumption, and cleanup, and physiological challenges with the changing pressure. The regulation of appetite stimulating hormone ghrelin, but not the appetite suppressor leptin, appeared to be sensitive to hypoxic conditions. Conclusions Food preparation capabilities and time for meals are important for promoting adequate food intake. Reduced appetite and food intake during missions may further be aggravated under hypoxic conditions through the suppression of ghrelin. Lack of time for meals on EVA days, and avoidance of potential gas-causing foods (e.g., health promoting fruits and vegetables) prior to EVAs, demonstrate the importance of scheduling ample recovery time between EVA days.

Grace L Douglas↗
NASA NTRS2023

Appetite and Food Intake During 11 Days of Mild Hypobaric Hypoxia

Introduction Reduced food consumption and loss of body mass and muscle mass have been observed during spaceflight. Hypoxic conditions that astronauts may encounter on exploration missions may further implicate satiety signals and dietary intake. Appetite, food intake, and satiety hormones were investigated under the conditions of mild hypoxia and high energy output during simulated extravehicular activity (EVA) to determine the adequacy of a mission relevant space food system to support energy balance and body composition. Methods Foods realistic to early Artemis missions was packed by meal for each subject for the 11-day test based on estimated energy requirements (EER) and estimated EVA caloric requirements. No hot water or food warmer was provided and only room temperature water was available to rehydrate food and beverages in-mission, mimicking plans for early Artemis missions. Measures included food records (pre-mission, in-mission); fasted body weight (pre-mission, in-mission); Dual-energy X-ray absorptiometry (DXA) (pre-mission, post-mission); subjective ratings and feedback of food acceptability, mealtime and meal preparation sufficiency, appetite, and nausea (in-mission); and circulating ghrelin and leptin concentration in fasted blood samples (pre-mission, in-mission: pre-post EVA). Results All subjects consumed fewer calories in-mission than predicted. On average, subjects consumed 341 calories less on EVA days compared to non-EVA days in-mission (p=0.0511). The total weight loss estimate from daily weight measurements (-1.1 kg, p=0.0028) is consistent with underconsumption and supported by DXA measurements (-1.3 kg total body mass, p=0.0123 and -1.6 kg fat mass, p=0.0016). In general, most foods that were consumed were given acceptable scores, but subject comments indicated that the most acceptable foods were those not intended to be heated. Comments also indicated that subjects found their favorite foods early in the mission and avoided the foods that they did not like throughout the mission. Habitability scores indicated that overall aspects of the food system were considered borderline or unacceptable over the length of this mission. Foods that caused gas were avoided pre-EVA to prevent discomfort during pressure changes. Average fruit and vegetable intake decreased during the mission, dropping from 4.8 servings/d pre-mission to 3.4 servings/d on non-EVA days in-mission (p=0.0872) and 2.3 servings on EVA days (p=0.0020). Fasting ghrelin concentrations tended to be lower pre-EVA and on non-EVA days when exposed to mild hypoxia compared to normoxic conditions pre-mission and post-EVA (p=0.0136). Fasting levels of leptin did not change. Discussion Food intake was reduced in-mission, resulting in a caloric deficit and weight loss for most subjects. Crew food and appetite ratings and comments indicated this was due to a combination of food choices, lack of preference, lack of preparation capability, lack of time for meal preparation, consumption, and cleanup, and physiological challenges with the changing pressure. The regulation of appetite stimulating hormone ghrelin, but not the appetite suppressor leptin, appeared to be sensitive to hypoxic conditions. Conclusions Food preparation capabilities and time for meals are important for promoting adequate food intake. Reduced appetite and food intake during missions may further be aggravated under hypoxic conditions through the suppression of ghrelin. Lack of time for meals on EVA days, and avoidance of potential gas-causing foods (e.g., health promoting fruits and vegetables) prior to EVAs, demonstrate the importance of scheduling ample recovery time between EVA days.

Lichar Dillon↗