Taxes on unhealthy food, limits to commercial advertising, a ban on chocolate drink at schools, or compulsory physical exercise for obese employees: efforts to counter the rise in overweight and obesity sometimes raise questions about what is ethically acceptable. This thesis examines how a structured debate can be facilitated about the ethical issues that are involved in the prevention of overweight and obesity. In the first part of this introduction I explain why this question is relevant, by providing some background information about the prevention of overweight and obesity and the ethical debate about it. In the second part of this introduction I outline how this question is addressed in this thesis.