Attention, fitness buddies! While it’s true that having a workout buddy is great, it turns out that when you apply the same accountability to a diet, having a partner may actually harm your health, according to a new study in the Journal of Health Psychology. When female roommates both dieted, the pairs reported more anxiety, depression, and disordered eating compared to when one roomie watched what she ate and the other noshed as she normally would. The women on a joint diet didn’t lose notably more weight than friends who ate as they normally would together—less than one pound to be exact. On the flip side, a study in JAMA Internal Medicine found that when one partner in a cohabiting couple made a healthy behaviour change, such as quitting smoking or exercising more, the other was more likely to follow suit.