Professional athletes were very strict with food. Especially athletes who were on the same level as Feifei Yu—champion of the Olympic games, world record holder, and champion of all swimming competitions. She was as precious as a baby panda. She had to pay full attention to everything she was putting in her stomach.
To ensure the food she was eating was safe for her to eat, she only went to places that had specified meals. Even if she ate out, she had to stick to the principle that she would not eat any meat, since all commercial meat had antibiotics, and sometimes even chemical hormones that were used to help animals grow faster. Antibiotics and hormones were taboo for athletes. Once one ate meat with those chemicals, even if by accident, it meant that he or she couldn't pass the urine test, and they would be forced to stop participating in sports games. It could even end their sports career.
