Introduction

The challenge presented to the author was to speculate what might emerge in the field of childhood obesity over the next 20 years. Though this sounds simple, readers will agree that predictions are usually wrong, and the broader the scope of the endeavour the greater the opportunity for error. Nevertheless, this chapter is written in the hope that, by being broad and speculative, it may stimulate efforts to prove at least some of the predictions wrong, thereby closing unproductive blind alleys and encouraging new avenues of research. The predictions range from the molecular and metabolic to the public health and political.

Assessment of childhood obesity

Clearly, we need a coherent, meaningful and preferably simple method for defining childhood obesity. The recent attempts by the International Obesity TaskForce (IOTF) were based on the idea that we needed coherence between childhood and adult indices of obesity. The choice of the centile of body mass index (BMI) at any age which corresponded, when children attained the age of 18, to BMIs of 25 and 30, was a straightforward, logical step (see Chapter 1). Of course, the choice of the BMI is crude, with groups of short and tall children of similar age and sex showing very different prevalences of overweight when a single BMI cut-off point is used (Franklin, 1999).