The prevalence of obesity has increased steadily for the past several decades. The great public health burden of overweight and obesity requires effective intervention programs targeting energy balance behaviours (e.g. active transport, tv viewing, soft drink and snacking consumption). However, up to now the efforts to prevent overweight had disappointing effects. To better inform future systematic intervention development and to improve effectiveness of energy balance behaviour interventions, identification of how the interventions worked (analyses of mediators) and for whom the interventions worked (analyses of moderators) is needed. Identifying mediators of intervention effects can prompt future intervention developers to strengthen or add effective intervention components and to remove ineffective intervention components resulting in more cost efficacious interventions. In addition, indentifying moderations can stimulate intervention developers can seek for new intervention strategies for non-responders. The aim of the proposed exchange program proposal is to bring the field of mediation and moderation analyses applied in obesity prevention research to a higher level by strengthening and enriching the international cooperation in this research field. All partners in the proposed exchange programme are experts in the field of overweight prevention and studies related to the determinants of overweight and unhealthy energy balance. Although all three partners are experts in the field of overweight prevention, each partner has specific expertise, which brings us to the goals of the current exchange programme. There are specific approaches and techniques that we can learn from each other and which can be further developed through an exchange programme. Eventually, this will bring our research field to a higher scientific level, which will have a direct impact on the overweight prevention and development of effective intervention programmes in Europe and Australia.