Last Published:  03/26/21 03:33:57 PM (Central)
Responsible Element: Human Health Countermeasures (HHC)
Status: Open
Initial State of Gap:
Energy balance studies have been conducted on short-duration Shuttle missions and there is no evidence that energy requirements are different during spaceflight; however, it is not known whether requirements change during long-duration missions.  Changes in fuel homeostasis and optimal provision of carbohydrate, protein, and fat have not been assessed.  Some ground and limited flight data suggest shifts in fuel homeostasis (e.g., impaired insulin sensitivity), but these have not been well characterized.

Interim steps:
    1.Energy expenditure studies need to be conducted throughout a long-duration mission on enough crewmembers to determine if a greater than 10% change from preflight exists in energy requirements given the known variability in energy requirements among a nominal healthy population [50% of gap completion]
    2.Evaluate relationship between diet macronutrient composition, dietary intake, resting energy expenditure, and clinical outcomes (related to exercise, bone, immune, performance, and cardiovascular health) [40% of gap completion]
    3.Update current standard based on results of the ESA Energy experiment and evaluation of diets from long-duration crewmembers [10% of gap completion]

Evaluate energy expenditure during long-duration (>3 mo) missions. 
  • Energy (PI: Blanc) – ESA sponsored, ongoing


Evaluate diet composition, intake, and resting energy expenditure and clinical outcomes related to exercise, bone, immune, cardiovascular health, and performance. 

  • Integrated Nutrition Countermeasure Study 


Target for Closure
Determine whether energy needs change by more than 10% during long-duration spaceflight and quantify the optimal balance of water, protein, carbohydrate, and fat in the diet in order to maximize performance, and minimize muscle/bone turnover. 
Risk Risk of Performance Decrement and Crew Illness Due to Inadequate Food and Nutrition
You are here! Gap N3.1: Determine the macronutrient requirements for spaceflight

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