That's not true. Chinese medicine has never heard of this. The food for nourishing yang and yin is determined according to different physique, illness, severity of illness, season and even personality preference. Shaoyang, Lao Yang, Shaoyin or Laoyin all need Yin and Yang to complement each other.

Besides, according to the theory of Yin and Yang, Yin and Yang change with time or season. Generally speaking, the most important thing during the day is noon, and the most important thing at night is midnight. It is better for ordinary people to eat something warm.