1. The worldwide epidemic of obesity in adults has been mirrored in children in developed and developing countries. 2. Central obesity appears to be driving a cluster of abnormalities often referred to as the metabolic syndrome. 3. The definition of the metabolic syndrome in children is not suited to arbitrary cut-offs and a definition using the significant clustering of risk factors that is already evident in childhood and adolescent populations may be preferable. 4. An Australian population study showed that 25% of 8-year-olds and 29% of 14-year-olds could be described by the high risk cluster with features similar to adult metabolic syndrome. 5. The high risk cluster was significantly linked to high and low birthweight, shorter duration of breast-feeding, larger postnatal weight gains after 12 months of age and raised C-reactive protein, gamma glutamyl transferase and alanine transaminase levels. At-risk young adults have also been shown to have macroscopic atherosclerosis in post-mortem studies. 6. Identification of at-risk children has obvious benefits for the individual and as well, for prevention of a future cohort with raised cardiovascular morbidity and mortality; however, complexities and controversies exist in doing so. Familial, genetic and lifestyle risk factors aggregate and labelling children with predisease may be problematic. Committed political and societal changes are necessary to reduce childhood obesity and subsequent adult cardiovascular disease.