Why do eight fonts have to be thin?

Scientifically speaking, there is no necessary relationship between a person's fatness and eight characters. Fat and thin have a lot to do with a person's spleen and stomach. Poor spleen and stomach function, poor absorption, generally thinner. It is also possible that the spleen and stomach are weak and cannot be transported well, and then there will be puffiness. There are various situations, and nothing is absolute.