Childhood obesity is one of the most serious global public health challenges of the 21st century. We are heading towards the first generation of children who will die younger than their parents. Childhood obesity is one of the most serious global public health challenges of the 21st Century, affecting 155m children worldwide. In the UK, the number of overweight children doubled in the 1990s. A third of UK children are at risk of obesity and it costs the country £4.2bn a year. We need to act now to prevent a catastrophic global epidemic of chronic obesity-related diseases such as Type 2 diabetes and premature death. Will you help combat childhood obesity?