We identified original research, reviews, and commentaries by searching PubMed using the search terms “paediatric obesity”, “childhood obesity”, “paediatric overweight”, “childhood overweight”, and “body mass index in children”. All dates and languages were considered. Articles published between 1962 and 2010 were included, but we directed special attention to reports published since 2002. Research developments and published work were also identified by discussions with specialists in
SeminarChildhood obesity
Section snippets
Epidemiology
8 years have passed since the last Seminar on childhood obesity in The Lancet.1 Our goal is to review new information and outline some of the remaining challenges. A review of secular trends in the number of overweight or obese children concluded that prevalence had increased during the past two to three decades in most industrialised countries, apart from Russia and Poland, and in several low-income countries, especially in urban areas.2 Prevalence doubled or trebled between the early 1970s
Differential diagnosis and complications
Endocrine diseases, congenital and acquired hypothalamic defects, genetic syndromes, and use of drugs affecting appetite should be considered during assessment of paediatric patients with obesity (figure 2). Clinical history and examination should guide differential diagnosis. Onset of obesity during early infancy raises suspicion of function-changing genetic mutations affecting the leptin signalling pathway, but these disorders are very rare, with the most common, melanocortin-4-receptor
Prevention
Prevention, especially in young people, is universally viewed as the best approach to reverse the rising global prevalence of obesity. However, evidence about the most effective means of prevention of obesity development in children is scarce. Many prevention trials have had sample sizes too small for expected effect size or insufficient length of follow-up. Some trials have also been criticised for not being based on sound theories of behavioural change and for having inadequate feasibility
Non-pharmacological treatment
We recommend that children with BMI higher than the 95th percentile, or higher than the 85th percentile when accompanied by comorbidities, such as hypertension, hyperlipidaemia, or impaired glucose tolerance, be considered for treatment. Non-pharmacological approaches should be the foundation of all obesity treatments, especially in children, and should always be considered as first-line therapy. In a systematic review109 of randomised controlled trials of treatments for childhood obesity,
Pharmacological and surgical treatment
A Cochrane review109 identified ten randomised controlled trials of pharmacological treatments for obese children. Most of these trials had small sample sizes (range 24–539 participants, with 60% including fewer than 30 participants), but most were high quality. With one exception, all the pharmacological treatment trials were in older children or adolescents (minimum age 12 years); the exception enrolled individuals aged 9–18 years. Trials meeting criteria for pooled meta-analysis included
Conclusion
Much progress has been made in understanding of the genetics and physiology of appetite control and, from this, the elucidation of the causes of some very rare obesity syndromes. Much work remains to be done, however, since these rare disorders have so far taught us few lessons about how to prevent or reverse obesity in most children. No evidence-based, clinically meaningful definition of childhood obesity has been established. Calorie intake and activity recommendations need to be reassessed
Search strategy and selection criteria
References (140)
- et al.
Childhood obesity: public-health crisis, common sense cure
Lancet
(2002) - et al.
Sensitivity and specificity of classification systems for fatness in adolescents
Am J Clin Nutr
(2004) - et al.
Disruption of intraflagellar transport in adult mice leads to obesity and slow-onset cystic kidney disease
Curr Biol
(2007) - et al.
Polycystic ovary syndrome in the adolescent
Obstet Gynecol Clin North Am
(2009) - et al.
Associations of size at birth and dual-energy X-ray absorptiometry measures of lean and fat mass at 9 to 10 y of age
Am J Clin Nutr
(2006) - et al.
Effects of prolonged and exclusive breastfeeding on child height, weight, adiposity, and blood pressure at age 6·5 y: evidence from a large randomized trial
Am J Clin Nutr
(2007) - et al.
NPY and Y receptors: lessons from transgenic and knockout models
Neuropeptides
(2004) - et al.
Impaired prohormone convertases in Cpe(fat)/Cpe(fat) mice
J Biol Chem
(2001) - et al.
Asthma, atopy, and airway inflammation in obese children
J Allergy Clin Immunol
(2007) Obesity and asthma
Immunol Allergy Clin North Am
(2008)