Every year 4th, 7th and 10th graders in Clark County schools are given a BMI screening. That's the physical exam that determines the Body Mass Index, the weight we should be depending on our size and age. Parents will receieve the screenings in a letter which in some states has been dubbed as the "fat letters." Do BMI screenings cause stress about body image among our youth? Are the screenings useful in helping kids make better health choices?