Instead of focusing on her acting or the ways Kenneth Branagh reimagines Cinderella as a feminist fairy tale, star Lily James has had to spend her time on the new movie's promotional tour defending and justifying her own body — in particular, her small waist.

During an interview with HuffPost Live on Monday, James, 25, said, "On one hand, it's upsetting. On the other hand, it's just boring. Why do women always get pointed at for their bodies?"

"And why has this whole thing happened where I'm constantly having to justify myself?" James, who is best known for her role as Lady Rose on Downton Abbey continued. "International Women's Day has just gone, and it just feels a bit sad that it's still happening."

See photos of Lily James through the years

James, who assures that "I'm very healthy and I always have been," explains that the costume, which features a corset and ballgown skirt, merely accentuates her natural small waist. And, for those of you who aren't familiar with corsets, that's exactly what corsets are supposed to do.

When the interviewer pointed out that women in society will always have to justify their size and what they're eating, James interrupted. "You shouldn't have to. I've always had a really healthy attitude towards my body. That's why in a way it's confusing me."

The controversy over James' body is the dark side of the so-called body acceptance movement, which often is not about body acceptance, but about criticizing the idealized skinny body. There is nothing helpful, healthy or feminist about shaming a woman for being skinny any more than there is about shaming a woman for being fat. And it's unfortunate that so much attention is being paid to James' body instead of celebrating the way her character in the film is not a victim saved by a prince, but a courageous young woman who refuses to let her circumstances define her.

So, please remember James' words next time you find yourself inclined to criticize a woman's size, because the shaming of any body helps no one.