Energy regulation in young people.

Obesity in young people is now realised as a worldwide crisis of epidemic proportion. The aetiology of this disease suggests a disruption in regulation of energy at the population level, leading to a positive energy balance and excess adiposity. The relative contribution of food intake and physical inactivity remains to be elucidated. Treatment interventions have aimed to create a deficit in energy balance through manipulation of physical activity, behavioural components or, to a lesser extent, dietary modification. Whether such intervention is maintained in the long-term is as yet unclear, however it seems a combination of therapies is optimal. Mindful of a mismatch between energy intake and expenditure, recent work has begun to examine the acute relationship between physical activity and food intake in children. Initial findings suggest a short-term delay in compensation through energy intake for exercise- induced energy expenditure. The overarching study of energy regulation in children and adolescents is clearly multifaceted in nature and variables to be assessed or manipulated require careful consideration. The collection of paediatric physical activity, energy expenditure and food intake data is a time-consuming process, fraught with potential sources of error. Investigators should consider the validity and reliability of these and other issues, alongside the logistics of any proposed study. Despite these areas of concern, recent advances in the field should provide exciting opportunities for future research in paediatric energy regulation on a variety of levels. Key pointsPhysical activity appears to be an effective intervention in paediatric weight-management, however future studies need to be extended over the longer-term employing consistent protocols to aid comparison.In the short-term, exercise-induced energy expenditure and subsequent energy intake do not appear to be tightly regulated in young people; this acute imbalance is similar to the 'loose coupling' of energy described for adults.The relationship between energy expenditure and food intake in young people requires further examination in longer-term interventions. A rigorous protocol is necessary to study parameters under free-living conditions.