This editorial is an attempt to encourage us to think about the balance between evidence and action in public health nutrition, so as to become much more effective as professionals working in the public interest. It is also about a theme that has been on my mind for some time now: the distinction between thinking as academic and acting as a professional. The issues that confront us are awesome. Throughout the world malnutrition in the classic definition is receding only very slowly, if at all. And as I write, new official figures show that roughly a quarter of 11-15-year-old schoolchildren in England are clinically obese, a figure that has almost doubled in the last decade, which is described by Colin Waine of the UK National Obesity Forum as 'a public health timebomb' 1. If this is war, we are not winning. Many would say we are losing. A theme of this editorial is that our weapons are ineffective.