Obesity and type 2 diabetes represent a serious threat to the health of the population of almost every country in the world. The World Health Organization estimates that 1.1 million people died as a result of diabetes in 2005, and this is almost certainly an underestimate. Moreover, the figure is expected to increase by 50% during the next ten years.

This escalation is due in part to increasing rates of childhood obesity. Until recently, type 2 diabetes was a disease that afflicted only adults. Now a growing number of children are being diagnosed with obesity-related type 2 diabetes. Also increasing is the incidence of 'metabolic syndrome' — a complex condition linked to obesity that is characterized by a cluster of closely related clinical features, including insulin resistance, dyslipidaemia and hypertension. Metabolic syndrome is associated with an increased risk of cardiovascular disease, which is ultimately responsible for a considerable proportion of diabetic mortality.

There is, therefore, an urgent need for new approaches to address obesity and type 2 diabetes and their associated complications. In particular, understanding the various processes that give rise to the characteristics of metabolic syndrome and its attendant risks — from abnormal regulation of energy metabolism through to dysfunction of molecular mechanisms — will pave the way for the development of new treatment strategies. And, as the reviews in this Insight highlight, it is hoped that a combination of preventative and therapeutic strategies will ultimately reduce the burden of type 2 diabetes on society.

We are pleased to acknowledge the support of Nestlé Research Center in producing this Insight. As always, Nature carries sole responsibility for all editorial content and peer review.