Objective: To observe the effects of simulated weightlessness on the nutritional state and contents of serum lipids in human.
Method: Eighteen healthy men were exposed to 21 d bed rest with -6 degrees head down tilt (HDT -6 degrees). Nutrients intake was calculated and the lipids levels were determined on the first, eleventh and twenty-first day.
Result: Intake of the three main nutrients, carbohydrates, protein and fat met the physiological requirement essentially, but carbohydrates intake was significantly reduced in the second week. There were no significant differences among the lipid levels during different periods.
Conclusion: Simulated weightlessness may exert a short-term and reversible influence on human nutritional intake except for lipids.