Are your friends making you fat? Maybe...

Drs. Walter Willett and Malissa Wood are the authors of Thinfluence: The Powerful and Surprising Effect Friends, Family, Work and the Environment Have on Weight, and they say that in order to maintain your weight, you may have to get rid of some toxic friends.

Willett and Wood believe that weight gain is in part a social thing -- it's impacted by what they call our "circles of influence." Factors like stress, anxiety and depression impact our overeating and healthy lifestyles, but we're also impacted by our social groups. That's why shows like the Biggest Loser are so successful -- because they show people who are coming together with a common goal of improving their lives in a specific way.

And that's also why, says Wood, you may have to thin out your social group if you're looking to, well, get thin. "If you know someone is going to drag you down and they're not interested in making a change, then I think it's important to kind of separate yourself from them, at least when you're in that behavior changing mode. You really have to get into a space where it is automatic that you're not going to drink six margaritas and eat four bowls of chips with your friends every time you go out. If they're not interested in doing something else, you'll have to break from them for a while." But chips and margs taste so good!

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Still, we know what she means -- friends are often the gateway drug to unhealthy eating. Instead of taco night, Wood recommends you plan friend and family dates that don't involve food. And if your social group can't understand, or won't accommodate your desire to get in shape, then you may have to drop 'em for the long haul. [The Atlantic]