Selina's most effective way to lose weight is gastroenteritis.

Okay, I admit that I am very unkind.

In fact,

During the publicity period

If she loses weight, it's basically because of dancing.

Non-public period

It should be to eat as little as possible (and it should be in summer)

Anyway, during the publicity, she won't let herself go hungry.

In winter, she herself said that she really couldn't bear to eat less in winter.