Studies on the impact of the 'obesogenic' environment have often used non-theoretical approaches. In this journal's debate and in other papers authors have argued the necessity of formulating conceptual models for differentiating the causal role of environmental influences on behavior.
Department of Health Education and Health Promotion, University of Maastricht, P.O. Box 616, 6200 MD Maastricht, The Netherlands. s.kremers@gvo.unimaas.nl
