Have something to do with it. People who feel flat are prone to vest lines, and some people who are not very thin will also have them. The so-called people born with vest lines are mostly such people; The round plate is difficult to come out, which may be related to the distribution of fat. A person with a flat figure has fat on both sides of the waist, so the waist is not thin from the front, but as long as it is not particularly fat, it generally has no stomach, and it is very thin from the side; A person with a round figure has fat on his stomach, so his waist is thinner before the meeting, but there will be a belly on the side.

(But it is also for this reason that people with round figure are easy to get A4 waist even if they are not very thin, while people with flat figure are not easy to get A4 waist. )