Professor Brian Walker, Professor of Endocrinology, delivers the third lecture in the 2015 Our Changing World series entitled, The Obesity Pandemic: Winners and Losers in Adapting to Affluence. Recent decades have seen a rapid increase in the prevalence of obesity, starting in the most affluent regions but now affecting low-middle income countries. This obesity pandemic has been attributed to increased food intake and decreased energy expenditure, and blamed for a parallel explosion in type 2 diabetes, but has resisted intensive efforts to avert it using drugs or lifestyle modification. And yet, not all obese people develop disease and not everyone in an "obesogenic environment" is equally susceptible to weight gain. In this lecture, Prof Walker will consider how individuals vary in their capacity to adapt to changes in energy balance and the implications for society's response to the obesity pandemic. Recorded on 13 October 2015 at the University of Edinburgh's George Square Lecture Theatre.