THey DO do something with the figures though - they are sent to the NHS who analyse them to find the areas where there are higher than average numbers of overweight children.
THen funding is given to schools / clubs in that area to encourage kids to do more exercise (ie. for after-school sports clubs, for sport equipment) and to eat well. Also in trying to educate parents ( through sure start centres etc).
Some Primary CAre Trusts have targets to meet to try to reduce numbers of overweight children in their area (or at least trying to slow down the increasing childhood obesity problem).
I know this cos I'm the person who's going to be analysing the figures in my area