Nutrition and responses to zero gravity

Area of Science:

• Space Medicine
• Human Physiology
• Nutritional Science

Background:

• Early space programs focused on minimizing food system mass through dehydrated foods and nutrient recycling.
• As spaceflight became a reality, focus shifted to food consumption mechanics in weightlessness and structuring conventional foods.
• Initial concerns about gastrointestinal function in flight were resolved, leading to investigations of subtle metabolic changes.

Purpose of the Study:

• To investigate the physiological and metabolic effects of spaceflight on the human body.
• To assess nutritional requirements and elemental losses during weightless flight.
• To evaluate the potential for nutrient manipulation to counteract spaceflight-induced deteriorative processes.

Main Methods:

• Extensive ground-based simulation studies were conducted.
• Carefully designed in-flight experiments were implemented.
• Data were collected on metabolic energy requirements and elemental losses in astronauts.

Main Results:

• No substantial impediments to normal gastrointestinal function were observed in flight.
• Slight changes in skeletal density, muscle mass, and overall body composition were noted.
• Data on metabolic energy requirements and major elemental constituent losses were presented.

Conclusions:

• Convincing evidence for long-term human adaptation to weightless flight is not yet available.
• Nutritional requirements during flight are qualitatively similar to those on Earth.
• Sophisticated manipulation of nutrient profiles shows potential for counteracting spaceflight-induced physiological deterioration.