Abstract
Much research is underway on the links between diet and obesity. So too are long-running disputes among nutritionists on core questions about the relationship. This editorial reviews the state-of-play on four issues: what makes people fat, how to lose weight, how much do we eat, and what policies to adopt towards obesity. The practical consequence is that, at present, frontline health professionals will not find in nutrition science agreed, actionable solutions to assist overweight patients. But research and debate continues actively.