"The system worked well. There were a lot of variety of vegetables to eat," said volunteer Gao Han, a student in his third year pursuing a Master's degree in biomedicine.

"If there is any improvement needed, I would want to eat eggs, which were not available in the lab. It would be better if there were more sources of animal fat," he said.

Volunteers drank water from a purifying machine. "Water is limited but sufficient for us to use for washing, cleaning vegetables and drinking every day," he said.