“Hey fatty!” “I’m so big back!” “We’re being such biggies right now!” Welcome to the latest teen-girl parlance—a TikTok-trend spinoff that’s become the new language of casual, constant joking used to poke fun at each other, and one’s self, for eating. And while many teens say the jargon is simply meant to be playful, others admit they find it hurtful, or at least jarring. Experts find the explosion of this kind of slang alarming.

“This is a problem for everybody,” says Zöe Bisbing , a body-image and eating-disorders psychotherapist. “It has a lot to do with this really, really entrenched anti-fat bias in our culture that normalizes microaggressions toward fat people.” Complicating the problem, though, is that the jokes are made by and about thin girls.

“With this new language, they’ve given each other permission to comment not only on weight but on eating itself. So there’s nothing good about this,” Barbara Greenberg , a teen and adolescent therapist based in Connecticut who is familiar with the terminology, tells Fortune . “It’s going backwards.

” Chanea Bond , a Texas high school English teacher and education influencer , tells Fortune she was disturbed as she watched the trend pick up steam before summer. “It started this school year. At first it was mostly students referring to themselves.

But now ‘big back’ it’s so common in their vernacular, they say it anytime there’s eating happening. Also, ‘You’re a fatty.’.