Explain from the word meaning: the reason why the word "fat" is added with "moon" is because the word "moon" here is next to the ancient word "meat moon". In seal script, the word "moon" is still the seal method of "meat". Later, seal script evolved into official script, which became next to the word "month" because of its inaccuracy, and later evolved into other fonts. So the word "moon" means "meat", and the combination of "meat" and "half" means that meat is half that of the average person. Of course, there is more meat. If you understand it, "fleshy" naturally means "fat".
The reason why the word "thin" is used next to the word "thin" is because most people think that being too thin is a pathological manifestation (which is different from losing weight in modern beauty), and modern medicine also thinks that thinness is indeed related to many causes, so the word "thin" with the word "thin" is considered to be too thin, abnormal and knowingly committed.
Although some people think that obesity is also a disease, at least it is easy to cause disease, people say that "obesity" is obesity in daily life. We know that people still have a good compliment on "obesity" and naturally it has nothing to do with "disease".