Health monitoring and clinical decision making in paediatric care largely depend on the availability of reference values for clinical parameters. Hence, the diagnosis of highly prevalent conditions in children and adolescents such as metabolic dysfunction has been hampered by the lack of a worldwide consensus on diagnostic criteria, as definitions and cut-offs being used in the paediatric population are frequently derived from the adult population. Providing globally applicable reference curves for the metabolic syndrome and its components, in early life - from birth to adolescence - represents a big step towards the ultimate goal: developing cut-offs for clinically relevant biomarkers for paediatric practice. By making use of the increasing availability of research data worldwide, we aim to establish a global pooling initiative building on a previously published special issue of the International Journal of Obesity "Filling the gap: international reference values for health care in children" (edited by Ahrens W, Moreno LA, Pigeot I), and further taking advantage of increased statistical power and variations across age groups, geographical regions and socio-cultural backgrounds. Thus, biomarker data for the metabolic syndrome are being collected, subsequently calibrated, harmonized, combined and analysed to provide age-, sex- and ethnic-specific reference curves for metabolic biomarkers to facilitate the diagnosis of metabolic syndrome in early life globally.