
You're probably gonna find an escape from beauty standards in a Korean webtoon of all things...they're notorious as a country for having high and unhealthy beauty standards (><lll). Moreover this is a noble-court historic; rich women are mean.
But I like that the male lead likes her regardless of how she looks, seeing as he fell for her as she is. But I don't think there's anything inherently wrong with the MC (who was a healthy Korean woman) wanting to become thinner for herself. She probably isn't feeling comfortable in another person's body for a variety of reasons.

i don’t understand?? isnt this manga about body positivity, shes choosing a healthy lifestyle, and even so she looks adorable being chubby… i think anyone who is also an unhealthy weight or not having the proper lifestyle/eating habits should try to loose weight. speaking from experience, i was really chubby and decided to go on a diet and loose weight
Thank you for reminding us that only skinny people are beautiful. We grew up with this bs and I try to read manhwa as an escape from the bs of the world only to find it here once again. Shame on manhwas like this. Why does she have to diet and be skinny in order to be pretty and loved?!