Interventions for preventing obesity in children

Background Prevention of childhood obesity is an international public health priority given the significant impact of obesity on acute and chronic diseases, general health, development and well‐being. The international evidence base for strategies to prevent obesity is very large and is accumulating rapidly. This is an update of a previous review. Objectives To determine the effectiveness of a range of interventions that include diet or physical activity components, or both, designed to prevent obesity in children. Search methods We searched CENTRAL, MEDLINE, Embase, PsychINFO and CINAHL in June 2015. We re‐ran the search from June 2015 to January 2018 and included a search of trial registers. Selection criteria Randomised controlled trials (RCTs) of diet or physical activity interventions, or combined diet and physical activity interventions, for preventing overweight or obesity in children (0‐17 years) that reported outcomes at a minimum of 12 weeks from baseline. Data collection and analysis Two authors independently extracted data, assessed risk‐of‐bias and evaluated overall certainty of the evidence using GRADE. We extracted data on adiposity outcomes, sociodemographic characteristics, adverse events, intervention process and costs. We meta‐analysed data as guided by the Cochrane Handbook for Systematic Reviews of Interventions and presented separate meta‐analyses by age group for child 0 to 5 years, 6 to 12 years, and 13 to 18 years for zBMI and BMI. Main results We included 153 RCTs, mostly from the USA or Europe. Thirteen studies were based in upper‐middle‐income countries (UMIC: Brazil, Ecuador, Lebanon, Mexico, Thailand, Turkey, US‐Mexico border), and one was based in a lower middle‐income country (LMIC: Egypt). The majority (85) targeted children aged 6 to 12 years. Children aged 0‐5 years: There is moderate‐certainty evidence from 16 RCTs (n = 6261) that diet combined with physical activity interventions, compared with control, reduced BMI (mean difference (MD) −0.07 kg/m2, 95% confidence interval (CI) −0.14 to −0.01), and had a similar effect (11 RCTs, n = 5536) on zBMI (MD −0.11, 95% CI −0.21 to 0.01). Neither diet (moderate‐certainty evidence) nor physical activity interventions alone (high‐certainty evidence) compared with control reduced BMI (physical activity alone: MD −0.22 kg/m2, 95% CI −0.44 to 0.01) or zBMI (diet alone: MD −0.14, 95% CI −0.32 to 0.04; physical activity alone: MD 0.01, 95% CI −0.10 to 0.13) in children aged 0‐5 years.