Obese children and adolescents can lose up to seven pounds over six to 12 months when they engage in at least 52 hours of behaviour-based lifestyle interventions. Minimal benefit was seen with shorter contact time, with less than 25 hours ineffective. The control group gained weight.
Rising obesity in the young is a global concern, which may lead to high rates of obesity-related diseases in adulthood. This review identified trials covering various weight management strategies. Lifestyle-based-interventions with sufficient contact time – as recommended by UK guidelines – showed clear benefits with no evidence of harms.
Investing in effective strategies to manage child obesity will ultimately save healthcare costs. Behaviour-based support should now be assessed for long-term weight loss and maintenance.
The evidence is still lacking whether universal child screening for obesity should be performed in the UK.
Why was this study needed?
Nearly a third of children in England aged two to 15 are overweight or obese. The World Health Organization labelled increasing worldwide obesity as a global epidemic.
Children with a high BMI are more likely to become obese adults. They are also more likely to have adverse cardiometabolic markers like raised blood pressure or poor blood sugar control. This may put them at increased risk of later developing serious diseases like heart disease and diabetes. The NHS spent about £5.1 billion on obesity-related ill-health in 2014/2015.
Tackling obesity is complex. The NHS offers lifestyle weight management programmes for overweight-obese children. The National Child Measurement Programme measures child BMI at school entry (age 4-5) and in year six (age 10-11). This is used for monitoring and to provide feedback to parents, but isn’t a specific screening programme.
This review aimed to explore the benefits and harms of screening and treatments for obesity in children.
What did this study do?
This systematic review identified 59 trials (8583 participants aged two to 18) since 2005 evaluating the effects of treatment for obesity in children. Most were conducted in the US, though four were UK based. No studies on screening were identified.
Forty-five studies examined behaviour-based lifestyle interventions of all kinds (including counselling on diet and physical activity), 11 examined the diabetes drug metformin and three the anti-obesity drug orlistat. The main outcome was weight/BMI at 12 months follow-up. Other outcomes included cardiometabolic measures, quality of life and harms.
Study recruitment had to be in a healthcare setting and relevant to primary care. School-based or residential studies were excluded, as were studies in children with obesity-related medical problems.
Limitations included the small sample size of individual trials and highly variable study methods, including interventions, reported outcomes, and length of follow-up. Quality was assessed using criteria defined by the US Preventive Task Force.
What did it find?
- Children receiving at least 52 hours of contact time in behaviour-based weight loss interventions showed greater reduction in BMI or BMI z score (how much BMI deviates from the norm for age and gender) than controls (mean difference [MD] -1.10, 95% confidence interval [CI] -1.30 to -0.89; six trials, 1049 participants). In terms of actual weight change from baseline children in intervention groups varied from +2 to -7lb vs +8 to +17lb among controls.
- Contact time between 26 and 51 hours was still effective compared to control but less beneficial (BMI or z score MD -0.34, 95% CI -0.52 to -0.16; nine trials, 721 participants). Weight change was highly variable, but all groups gained weight ranging from +1lb to +5 lbs in the intervention group vs +5 to +10lbs among controls. Less than 25 hours was ineffective.
- Lifestyle-based interventions showed small improvements in blood pressure (systolic blood pressure MD -6.4mmHg [95% CI -8.6 to -4.2]; diastolic blood pressure MD -4.0mmHg [95% CI -5.6 to -2.5]; six trials). There was no effect on blood lipids (fats) or blood sugar, nor any effect on quality of life measures.
What does current guidance say on this issue?
NICE recommends that care for children and young people with obesity should be tailored to the individual’s and family’s needs following the approaches outlined recently in the Department of Health’s “A call to action on obesity in England”.
NICE public health guidelines outline the required components of lifestyle weight management programmes. They should be multicomponent, including behaviour change strategies and positive parenting skills, with long-term follow-up by a trained professional.
NICE advises against drug treatment for children under 12. Orlistat is only recommended for over-12s who have a severe related illness (such as sleep breathing problems), and only in a specialist paediatric setting.
What are the implications?
The review supports current guidance, showing that lifestyle behaviour-based interventions can work to reduce excess weight when delivered with sufficient contact time. However, obesity is multifactorial in cause and prognosis. Follow-up was limited to 12 months, which gives little indication whether weight loss is maintained. It is also not possible to inform on the optimal programme content.
The review identified no studies exploring whether universal child screening would be beneficial, or may be associated with adverse harms to children or their families. The question of how best to identify at-risk children remains unanswered.
Citation and Funding
O’Connor EA, Evans CV, Burda BU, et al. Screening for Obesity and Intervention for Weight Management in Children and Adolescents: Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2017;317(23):2427-44.
This research was funded by the Agency for Healthcare Research and Quality (AHRQ), US Department of Health and Human Services, under a contract to support the USPSTF.
DH. Childhood obesity: A plan for action. London: Department of Health; 2017.
NHS Choices. Treating obesity. London: Department of Health; 2016.
NHS Digital. National Child Measurement Programme. London: NHS digital.
NICE. Obesity in children and young people: prevention and lifestyle. PH47. London: National Institute for Health and Care Excellence; 2013.
NICE. Obesity: identification, assessment and management. CG189. London: National Institute for Health and Care Excellence; 2014.
Must A, Anderson SE. Body mass index in children and adolescents: considerations for population-based applications. Intl J Obes (Lond). 2006;30(4):590-94.
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