The current systematic review and meta-analysis was prepared according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement for reporting systematic reviews and meta-analyses (checklist is provided in Additional file 1: Table S1). Therefore, the aim of the current study was to systematically search controlled trials that evaluated the effectiveness of pediatric obesity prevention policies among children and adolescents and to analyze the effectiveness of these policies on the study outcomes of body mass index (BMI) and BMI-Z score (BMI-Z) measurements while considering a possible dose–response association with preventive tools. Although there is evidence to support the beneficial effects of increased PA and diet as a basic and early strategy at any time and for any age against obesity, no summarized study is available to critically evaluate the effectiveness of different policies with different interventional approaches in prevention of childhood obesity considering the role of setting, age, geographical distribution, and intervention type or strategy. Some previous systematic reviews have focused on childhood obesity prevention programs that were not at national, governmental or macro-population level policies or that focused on some specific interventional approaches, including changes in physical activity (PA), diet and education. The effectiveness of childhood obesity prevention programs has been shown by previous Cochrane reviews. Obesity prevention is a public health priority around the world. The National Academy of Sciences recommended that more attention should be paid to providing opportunities to choose healthy foods in society. Developing and implementing effective strategies to prevent childhood obesity is difficult at the population level. Although the underlying reasons of genetics and individual behavior for being overweight in adults and young people are almost the same, obesity prevention policies in the younger age group are different from those adopted in adulthood. According to a recent study in the United States comparing the cost–benefit of prevention versus treatment interventions in youth, preventive interventions in the early stages of life were found to be more beneficial than in adulthood, and addressing childhood obesity as early as possible is an effective strategy against obesity in later ages. Obese children are at greater risk of obesity in adulthood a recent study of 200,777 participants showed that 80% of teens with obesity remained obese in adulthood and this continued with a prevalence of 70% past the age of 30. Nearly one in five children and adolescents are overweight or obese, and the growing prevalence of obesity in youth has led to an alarming increase of 18.5% in children and adolescents between the ages of 2–19 years. Obesity among children and adolescents is a leading cause of health and contributes to cardiovascular disease, cerebrovascular disease, and metabolic diseases. Overweight and obese children persist as a serious health problem and a public challenge of the twenty-first century.
#COMPREHENSIVE META ANALYSIS TRIAL DOWNLOAD REGISTRATION#
Trial registration PROSPERO registration number: CRD42019138359 In conclusion, the obesity prevention policies in short-term periods of less than 2 years, in rather early age of school with approaches of change in both of diet and physical activity, could be more effective in prevention of childhood obesity. In subgroup analysis, the more favorite results were observed for 5–10 years old, with combination of physical activity and diet as intervention materials. In dose–response meta-analysis, a non-linear association was reported between the duration of intervention and BMI (P nonlinearity < 0.001) as well as BMI-Z score (P nonlinearity = 0.023). The results showed that the obesity-prevention policies had significant effect in reducing BMI (WMD: − 0.127 CI − 0.198, − 0.056 P < 0.001). Forty-seven studies reported BMI, while 45 studies reported BMI-Z score as final outcome. Three databases (SCOPUS, PubMed and Embase) were searched for studies published before the 6th April 2020, by reported outcome measures of body mass index (BMI) and BMI-Z score. In the current meta-analysis, we summarized the results of controlled trials that evaluated the effect of obesity prevention policies in children and adolescents. Childhood obesity persists as a serious public health problem.