You know the drill: Your friend picks her body apart, harping on everything from her jiggly arms to her imagined muffin top, and soon you’re cringing in agreement about your own body. But don’t do it—research says “fat talk” just eggs each other on! A recent study asked 87 college women of average weight to discuss an ad featuring a skinny model.

Unbeknownst to them, two women in the discussion were in cahoots with researchers and had different missions during each session—fat-talking in agreement, one fat-talking with the other challenging it, or not fat-talking at all. In result, the women who overheard fat talk were more likely to fat talk themselves and felt worse about their body, especially when the fat talk wasn’t challenged. It’s official: Fat talk isn’t just unproductive and negative, it’s contagious!

MORE: Ditch Your Fat Talk Habit