We all know that body shape is very important to Koreans. We have seen Korean dramas and some Korean variety shows. We all know that there are no Korean artists on the show. They are very fat. Basically, they all look slim and have a bumpy figure. Especially for some Korean women, their figure can be said to be equivalent to their life. If they don't have a good figure, they may not get along in the entertainment circle, which may cause a series of burdens to their performing arts career.
Therefore, they control their bodies very well, never show signs of getting fat, and they can't see too much obesity when taking black photos. But for China people, in order to achieve a visual effect when filming, they may gain some weight, but it does not exist in Korean dramas.
After all, Korean drama actors can invite some body double or change roles if they want to create visual effects. His weight can't change very much, because it is likely to cause him to lose some fans. Everyone knows that South Korea is a country that attaches importance to plastic surgery. If some Korean artists reach a certain weight, they are likely to be questioned as plastic surgery, in order to avoid this situation. So their size is very important to them. After all, they also live by their body shape.