Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, Australia; Academic Department of Adolescent Medicine, The Children's Hospital at Westmead, Australia. Electronic address: natasha.armaghanian@health.nsw.gov.au. School of Molecular Bioscience, University of Sydney, Australia; Boden Institute of Obesity, Nutrition and Exercise, University of Sydney, Australia. Boden Institute of Obesity, Nutrition and Exercise, University of Sydney, Australia; Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, Australia. Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, Australia; Academic Department of Adolescent Medicine, The Children's Hospital at Westmead, Australia; Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, Australia.