Nutritional assessments of astronauts before, during, and after spaceflight ensure adequate intake of energy, protein, and vitamins during missions. Scientists use the information to understand the connections between nutrition and human health during space flight, and to develop effective dietary strategies to reduce adverse health impacts.Principal Investigator(s)
National Aeronautics and Space Administration (NASA)Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)Research Benefits
Information PendingISS Expedition Duration:
November 2000 - April 2007Expeditions Assigned
1,2,3,4,5,6,7,8,9,10,11,12,13,14Previous ISS Missions
Similar studies were completed during NASA/Mir.
To provide nutritional recommendations to crew members for
long-duration space travel, we need to better understand how nutritional status and general physiology are affected by the microgravity environment. Dietary intake during space flight has often been inadequate, and this can greatly compromise nutritional status. Data from both short- and long-duration space flights provide evidence that energy intake is typically 30-40% below World Health Organization recommendations, but energy expenditure is typically unchanged or even increased. This imbalance
may explain some of the observed negative changes in overall nutritional status during flight. However, blood concentrations of some nutrients, such as vitamin D, continue to be low even when astronauts receive supplements during flight. The space environment itself results in physiologic changes
that can alter nutritional status. For example, changes in iron metabolism are closely associated with blood chemistry alterations during space flight. Similarly, increased levels of radiation and oxidative stress during flight likely contribute to decreased antioxidant status and genetic damage during or after space flight.
There are six components to the research program.
Nutritional monitoring is vital to ensuring crew health during long-duration space flight. The results are being used to identify specific effects of microgravity on nutrient-depended processes such as vitamin uptake, antioxidant production, and metabolism of iron. Alterations to nutrient assimilation in microgravity are also important for studies of bone loss while in microgravity.Earth Applications
Increased understanding of the connections between nutrition and bone loss has potential value for patients suffering bone loss on Earth.
Data collection is completed on every ISS expedition as it is a requirement for medical monitoring during the flight. Body mass, FFQ, and blood sample data is downlinked on a weekly basis for review by the flight surgeon.Operational Protocols
Astronauts use the FFQ program to record their menu choices during the week as other operational duties and tasks allow. Astronauts also include vitamin supplements (such as Vitamin D) with their daily food intake. Body mass measurements are taken each week by each US astronaut using the body-mass measuring device. Blood samples are analyzed using finger sticks and the onboard analyzer to monitor blood pH and ionized calcium levels on a weekly basis. This information is recorded and downlinked each week to the flight surgeon, who uses the information to track the nutritional status of each astronaut. If decreases in body mass or nutritional balance are noted, the flight surgeon may advise the astronaut on measures to compensate.
Results have been compiled and analyzed for ISS crewmembers. Intake of energy (relative to World Health Organization standards) was observed to generally decrease over time during missions. However, when dietary
counseling was provided to a single astronaut during flight, adequate energy intake was maintained throughout the mission. Body weight, total bone mineral content, and bone mineral density decreased during flight. Antioxidant
capacity decreased during flight, leading to increased susceptibility to genetic damage from radiation. Vitamin D concentration in crew bone was decreased, and bone resorption increased, by long exposure to microgravity. The relative concentrations of other blood and urine analytes preflight and postflight were variable and subject to several confounding factors that limit conclusions as to particular effects of space flight (Smith, 2005, 2008). The results of this study formed the basis for the Nutrition and repository experiments, currently being operated on the ISS.
Additionally, these data have been used by other medical researchers performing experiments on the ISS. Crosscutting results on bone health in space were reported in Cavanaugh and Rice, 2007 (see Smith et al. 2007; Hall et al. 2007). (Evans et al. 2009)
Zwart SR, Shackelford LC, Sibonga J, Ploutz-Snyder LL, Heer MA, Smith SM. Benefits for bone from resistance exercise and nutrition in long-duration spaceflight: Evidence from biochemistry and densitometry. Journal of Bone and Mineral Research. 2012 Sep; 27(9): 1896-1906. DOI: 10.1002/jbmr.1647.
Zwart SR, Smith SM. Nutrition issues for space exploration. Acta Astronautica. 2008; ;63: 609 - 613.: 609-613. DOI: 10.1016/j.actaastro.2008.04.010.
Hall PS. Past and Current Practice in Space Nutrition. Cleveland, OH: Bone Loss During Spaceflight: Etiology, Countermeasures, and Implications for Bone Health on Earth.; 2007.
Zwart SR, Block G, Rice BL, Davis-Street JE, Smith SM. The nutritional status of astronauts is altered after long-term space flight aboard the International Space Station. Journal of Nutrition. 2005; 135(3): 437-443.
Lane HW, Smith SM. Gravity and space flight: effects on nutritional status. Current Opinions in Clinical Nutrition and Metabolic Care. 1999; 2: 335-338.
Davis-Street JE, Rice BL, Nillen JL, Gillman PL, Block G, Smith SM. Nutritional status assessment in semiclosed environments: ground-based and space flight studies in humans. Journal of Nutrition. 2001; 131: 2053-2061.