NASA Tracks ISS Astronauts' 80% Calorie Intake as Microgravity Erodes Muscle and Bone
Updated
Updated · spacedaily.com · Jul 8
NASA Tracks ISS Astronauts' 80% Calorie Intake as Microgravity Erodes Muscle and Bone
2 articles · Updated · spacedaily.com · Jul 8
Summary
NASA’s Nutritional Biochemistry Laboratory monitors ISS crews’ diet and body mass across four-to-six-month missions because astronauts have averaged only about 80% of recommended energy intake in orbit.
Microgravity quickly shifts fluids toward the head, causing congestion that can blunt smell and taste, but NASA and outside studies say that alone does not explain why appetite stays weak after the first weeks.
About 600 minutes a week of exercise still does not fully prevent deconditioning: a 2023 analysis of 46 astronauts estimated up to 17% could face performance-limiting declines under current countermeasures.
Six-month station missions already show weight loss, bone resorption and oxidative damage; on Artemis or eventual Mars missions lasting years, even modest daily calorie deficits could become a mission risk.
With space itself killing appetite, how can NASA solve the critical undereating problem that threatens long-term missions?
If today's best countermeasures are failing, what breakthrough will prevent Mars astronauts' bodies from breaking down on a three-year journey?
The 2026 Astronaut Health Report: Tackling Muscle Atrophy, Bone Loss, and Immune Risks in Deep Space
Overview
As humanity enters a new era of innovation and exploration, astronaut health has become a top priority for deep space missions. NASA is planning more challenging lunar missions, aiming for scientific discovery, economic benefits, and a lasting human presence on the Moon. These efforts are essential for building the knowledge and capabilities needed for future crewed missions to Mars. The ambitious goals and long durations of these journeys highlight the urgent need to address the complex physical and psychological challenges astronauts face, ensuring their well-being far beyond Earth's protective environment.