The Chinese overlay the concept of yin & yang on a lot of things and Food is one of them. So all foods are divided into ‘heaty’ foods and ‘cooling’ foods. Fried Food, for example, is considered ‘heaty’ which means it gets your body all excited and sweaty. According to Chinese grandmothers (who like all other grandmothers have a direct line to secret-stuff), to make things stable, you have to have some ‘cooling’ food along with the ‘heaty’ ones.
Interestingly, this concept is not particularly alien to me since it appears in many local Indian cultures too. The Konkan coast (ie. most of India’s western coast) for example uses Sol Kadi, a drink made from Kokum, to cool down the body after ingesting huge amounts of ‘heaty’ seafood, particularly shrimp (to experience what I am talking about, try one of the famous seafood restaurants of Mumbai such as Mahesh or Saiba). Ayurveda too makes a lot of this concept and recommends eating both hot & cold foods to balance one’s ‘kapha dosha’.
The most interesting aspect of all of this is, how two of Asia’s earliest cultures (and two of the world’s most ancient systems of health-care) both recognise the primacy of ‘balance’ in well-being.