The rapid rise in rates of overweight and obesity among adults and children in Australia and New Zealand has intensified debate about the most effective policies for obesity prevention. Law has much to contribute to this policy discussion, although its role is often misunderstood. The articles in this symposium follow on from a conference hosted in September 2006 by the Centre for Health Governance, Law & Ethics in the Faculty of Law, University of Sydney, titled: Obesity: should there be a law against it? In different ways, these articles provide a variety of perspectives on regulatory responses to obesity, including theoretical justifications for a legal approach, conceptual models that assist in making sense of law's role, as well as specific legal strategies for obesity prevention in various settings.