Study in Toulouse: Volunteers Simulate Spaceflight Conditions Through 10-Day Bed Rest and Fasting

Toulouse – 18.06.2026: In Toulouse, ten healthy men have begun a 10-day study during which they remain lying down and receive a reduced calorie intake to examine the effects of weightlessness and food reduction on the human body. This investigation is being conducted by the Centre National d’Études Spatiales (CNES) in collaboration with the Institute of Medicine and Physiology of Space (MEDES).

The participants spend the entire time lying down, with their feet positioned slightly higher than their heads to mimic the conditions of weightlessness. During this phase, they receive only 250 calories daily, consisting of a spoonful of honey, a cup of broth, and a glass of fruit juice. This strict diet is intended to study the effects of food reduction under simulated weightlessness conditions.

The study aims to better understand how the human body responds to the combination of weightlessness and food reduction, particularly with regard to future long-duration space missions. The data obtained are intended to help ensure the health and performance of astronauts during extended stays in space.

Such studies are crucial for understanding the physiological changes that can occur during extended space missions. Previous research has already shown that the human body reacts to weightlessness with changes in the muscular and skeletal systems. By combining these effects with food reduction, researchers hope to gain a more comprehensive picture of the challenges astronauts face during long missions.

The results of this current study are expected to provide valuable insights that could be important not only for spaceflight but also for medical applications on Earth. They could, for example, help better understand how the human body reacts to extreme conditions and which measures can be taken to minimize negative impacts.

The study is overseen by a team of doctors and scientists who ensure the health and safety of the participants throughout the experiment. All participants were carefully selected and must undergo regular medical examinations to confirm their suitability for the study.

This research is part of a broader program by CNES and ESA aimed at investigating the effects of long-term stays in space on the human body and developing strategies to minimize these effects. Such studies are essential to ensure the safety and well-being of astronauts on future missions.

The results of this study are expected to be published in the coming months and could provide important impetus for future space research and medicine.