BackgroundResearch into lifetime costs of obesity in childhood is growing. This review synthesizes that knowledge. MethodologyA computerized search of the international literature since 2000 was conducted. Mean total lifetime healthcare and productivity costs were estimated and inflated to 2014 Irish euros. ResultsThis resulted in 13 published articles. The methodology used in these studies varied widely, and only one study estimated both healthcare and productivity costs. Cognizant of this heterogeneity, the mean total lifetime cost of a child or adolescent with obesity was Euro149,206 (range, Euro129,410 to Euro178,933) for a boy and Euro148,196 (range, Euro136,576 to Euro173,842) for a girl. This was divided into an average of Euro16,229 (range, Euro6,580 to Euro35,810) in healthcare costs and Euro132,977 (range, Euro122,830 to Euro143,123) in productivity losses for boys and Euro19,636 (range, Euro8,016 to Euro45,283) and Euro128,560, respectively, for girls. Income penalty accounted for the greater part of productivity costs, amounting to Euro97,118 (range, Euro86,971 to Euro107,264) per male adolescent with obesity and Euro126,108 per female adolescent. ConclusionsHealthcare costs and income penalty appear greater in girls while costs because of workdays lost seem greater in boys. There is proportionality between body mass index and costs. Productivity costs are greater than healthcare costs.