NHMRC Clinical Trials Centre, University of Sydney, Camperdown, New South Wales, Australia. Center Child Health Research, School Exercise Nutrition Sciences, Queensland University Technology, Brisbane, Queensland, Australia. School of Public Health, Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia. Department of Medicine, University of Otago, Dunedin, New Zealand. Health Promotion Unit, Sydney Local Health District, School of Public Health, University of Sydney, Camperdown, New South Wales, Australia. Institute for Physical Activity and Nutrition, Deakin University, Geelong, Victoria, Australia. School of Public Health, Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, Australia. Dunedin School of Medicine, Office of the Dean, University of Otago, Dunedin, New Zealand. Nutrition and Dietetics, College of Nursing and Health Sciences, Flinders University, Adelaide, South Australia, Australia. Discipline of Child and Adolescent Health, University of Sydney, Clinical School, The Children's Hospital at Westmead, Camperdown, New South Wales, Australia.