and that's why it's important to watch for warning signgn katie tells us more. >> americans tend to be very concerned about how they look. in fact, more than half of teen girls believe that they are overweight. yet 80% of those who think they're overweight really aren't. obsessing on how much you weigh and how thin you look, can be downright unhealthy. dr. megan jones is a psychologist from stanford university, and she's here to discuss this. welcome. >> thanks for having me. >> so, doctor, when it comes to worrying about weight, how can i tell if i'm going overboard? >> well, there are some common warning signs that we like to think of that will give you a clue that maybe it's going too far. >> okay, so can you give me some of the warning signs? >> sure. the first one is describing fat as a feeling. so, when you hear yourself say even talk about yourself as being too fat, that's a clue that you might be too self-critical and that your appearance is becoming so important that it's affecting the way you feel about yourself. >> okay. give me another warning sign? >> another is cutting ou