Bridging Space and Military Nutrition: Energy Balance Challenges and Countermeasures in Extreme Environments

This critical review underscores the profound challenges of maintaining energy balance in high-consequence occupations in extreme environments, revealing fundamental differences, such as microgravity, radiation, and isolation stressors during spaceflight compared with terrestrial extremes of altitude and temperature during military operations. Herein, we highlight substantial logistical and physiological overlaps in mechanisms like appetite suppression, gastrointestinal disturbances, exercise-induced satiety signaling, sleep deficits, and psychological strain. These distinct and shared dynamics perpetuate negative energy balance, culminating in comparable sequelae that jeopardize mission success and long-term health. By synthesizing evidence from short and long-duration space missions with military training and operational contexts, we identify translational opportunities for optimizing dietary intake and minimizing the consequences of negative energy balance. We highlight issues pertaining to food palatability and antioxidant and micronutrient status, and we explore novel countermeasures to minimize musculoskeletal tissue degradation and maintain functional capacity.