Childhood obesity rates are on the rise worldwide. The myriad of physical and psychological health consequences associated with childhood obesity is staggering. Emphasis must be placed on addressing this public health dilemma from both a preventative and treatment perspective.Evidence-based parent-centered interventions are a potentially effective way to target childhood obesity. Parents play a key role in a child's lifestyle habits, and research has demonstrated that interventions involving parents are more effective than interventions exclusively targeting the child.Despite this, recruitment of parents into obesity-specific programs has been problematic. This challenge must be addressed from a population health framework if improvements in childhood obesity rates are to be achieved.This thesis provides a framework for the prevention and management of childhood obesity from a public health perspective. Two randomised controlled trials are presented. First, a trial of a brief universal parenting program for the prevention of childhood obesity (Lifestyle Triple P Seminar Series); and second, a trial of an intensive 14-session parenting program for children who are already overweight or obese (Group Lifestyle Triple P). Support will be provided for a public health multilevel model of parenting support that blends a targeted intervention for overweight and obese children, with a universal brief preventative intervention for all children regardless of weight status.Chapter 1 discusses the increased prevalence rates and considerable health risks associated with childhood obesity. The complex aetiology of obesity development will be described within a socioecological perspective. The research evidence supporting a multicomponent parent-centered approach to childhood obesity management will be presented. The shortage of well-controlled research trials evaluating such programs will be highlighted.Chapter 2 details the rationale for a public health approach to preventing and treating childhood obesity. It describes the Lifestyle Triple P multilevel system, and reviews the existing evidenceiii base for these interventions. Future research needs and challenges associated with a public health approach to parenting support will be discussed.Chapter 3 evaluates the effectiveness of a new universal parenting program for obesity prevention in a randomised controlled trial (RCT) with a 12-month follow up. The Lifestyle Triple P Seminar Series targets all parents regardless of child weight status. It is designed as a health promotion tool to engage parents on a population level, and increase healthy parenting practices in general and lifestyle-specific domains. A combination of self-report and objective assessment measures was used to investigate intervention outcomes from pre-intervention, post-intervention, 6-months and 12-months follow-up. Following the intervention, there were significant improvements in overall dysfunctional parenting style, laxness, verbosity and overreactivity, both lifestyle-specific and general p...