Thanks for letting me know this bit of information. I did not know that some states are doing this. I can see why they are doing this in light of the health epidemic and the obesity problem among young people. This is probably the first time in history where such a problem exists. In light of this, I think giving the BMI is a good idea for two reasons.
First, some people are ignorant when it comes to body mass index and this can help them to get in shape. As they say ignorance is bliss. So, if people had their BMI and knew how to read the BMI, then they can take a greater initiative to do something about their health.
Second, it is important for families to get involved as well. So, if test scores are given as well as BMI, parents will be in the know. They may do something to help their children to watch their weight.
As long as this BMI is private, I see no problems at all.