Letter to the EditorDiagnosis of childhood obesity using BMI: potential ethicolegal implications and downstream effects: a responseAuthorsM. Simmonds,Centre for Reviews and Dissemination, University of York, York, UKSearch for more papers by this authorA. Llewellyn,Centre for Reviews and Dissemination, University of York, York, UKSearch for more papers by this authorC. G. Owen,Population Health Research Institute, St George's, University of London, London, UKSearch for more papers by this authorN.