Fat talk is contagious.

Remember that “Sex and the City” episode where Carrie, Miranda and Charlotte are all complaining about their bodies—and Samantha refuses to join in? Our feisty Sam may be on to something.

In this study, 87 college women of healthy weight discussed an ad showing a beautiful, thin model. But the women didn’t know there was a twist: Two of the women in each discussion were “confederates,” secretly in cahoots with the researchers.

In the first scenario, the two confederates “fat talked,” or said negative comments about their own bodies, like: “Ugh, look at her thighs. Makes me feel so fat.” In the second scenario, one of the confederates fat talked, but the other challenged her, saying she wished women wouldn’t disparage their bodies. In the third scenario, the confederates didn’t fat talk at all.

The result? Women who heard the confederates fat talk (especially when it wasn’t challenged) were more likely to fat talk themselves, felt worst about their bodies, and felt most guilty.

Looks like fat talk can snowball, with consequences: the more a woman complains about how she looks on the outside, the worse she feels on the inside.

Next time a friend complains about her body, don’t bite the bait! Instead of joining in by complaining about your own body, tell her that it’s a shame that she and so many other beautiful women feel a need to put down their bodies. Change the subject to something else—like what’s really behind a “fat day”. Or a book you read and loved.

Read More by Renee Engeln-Maddox:
Meet the Mind: Renee Engeln-Maddox
Women Think Thinness Equals Success
Thin Models Are Mood-Killers
Thin Women Fat Talk