Yes, Mom, you should monitor your kids' friends.

     It's obvious, but research from Gallup indicates that people who smoke or drink tend to hang out with people who also smoke or drink, and overweight people hang with other overweight people..and I think there's a pretty clear warning for parents that a) if they smoke or drink or eat too much, their kids will be more likely to, and b) if your kids hang with kids...etc. etc.