Although there have been positive pockets of change, no country has yet turned around its obesity epidemic. Preventing an increase in obesity prevalence will require urgent actions from government as well as a broader spectrum of stakeholders than previously emphasized. In this paper, we review a number of regulatory and non-regulatory actions taken around the world to address obesity and discuss some of the reasons for the patchy progress. In addition, we preview the papers in this Lancet series, which each identify priority actions on key obesity issues and challenge some of the entrenched dichotomies that present obesity and its solutions in “either/or” terms. Although obesity is acknowledged as a complex issue, many debates about its causes and solutions are centered around overly simple dichotomies that present seemingly competing perspectives. Examples of such dichotomies explored in this series include: individual versus environmental causes of obesity, personal versus collective responsibilities for actions, supply versus demand explanations for consumption of unhealthy food, government regulation versus industry self-regulation, top down versus bottom up drivers for change, treatment versus prevention priorities, and under versus over nutrition focus. In the current paper, we explore the dichotomy of individual versus environmental drivers of obesity, which lay out two truths: people bear some personal responsibility for their health and environmental factors can readily support or undermine the ability of people to act in their self-interest. We propose a re-framing of obesity that emphasizes the reciprocal nature of the interaction between the environment and individual. Current food environments exploit people’s biological, psychological, social, and economic vulnerabilities, making it easier for them to eat unhealthful foods. This leads to preferences and demands for foods of poor nutritional quality, thus sustaining the unhealthful food environments. Breaking these vicious cycles will need regulatory actions from governments and greater efforts from industry and civil society.