Regulatory measures, including taxes and subsidies on food and beverage products, food labelling requirements, regulation of food content and regulation of food marketing, have been proposed to encourage healthier eating and prevent obesity. The objective of this article is to explore the extent to which international trade agreements affect governments' choices to use such regulatory measures.It reviews key provisions of relevant World Trade Organization (WTO) agreements and their implications. Some insights can be gained by examining 2 recent developments in the WTO regarding tobacco control: a current dispute involving Australia's plain packaging law and its effect on trademarks, and a recent decision involving the United States law banning flavoured cigarettes.This decision said that the ban did not restrict trade more than necessary to fulfil its legitimate health objective, but it was discriminatory because it banned imported products (clove cigarettes) while exempting domestic products (menthol cigarettes) with similar characteristics.The conclusion we can draw from this decision is that WTO member states probably enjoy a significant degree of latitude in developing food regulations as part of an obesity prevention strategy, so long as those do not disproportionately affect imported products and therefore raise questions of discrimination. The approach taken in this case encourages the adoption of public health policies that are consistent with strong scientific evidence, but may restrict governments' ability to make political compromises, which could frustrate some proposals. The ongoing development of WTO law will continue to affect policy choices in public health.