Some dances are thin. I remember a report listing the effects of some dances of Korean women's groups on weight loss. For example, when I was young, I got a boy with thin arms. The diet of Korean women's groups is also very strict. Just look at APINK NEWS 1. Also, the company is very concerned about the physique of stars, so SM requires every trainee to do morning exercises. Stars eat less and exercise more every day and work hard. How can they not lose weight? You can also have stovepipe needles. But some little-known groups will do that. But famous teams rarely do this.

(Personal opinion only, don't spray! )