Elements of Effective Population Surveillance Systems for Monitoring Obesity in School Aged Children

Abstract

The continuing high prevalence of child overweight and obesity globally means that it remains the most common chronic health condition in children. Population-based child obesity surveillance systems are critical for monitoring trends in obesity and related behaviours, and determining the overall effect of child obesity prevention strategies. Effective surveillance systems may vary in methods, scope, purpose, objectives, and attributes, and our aim was to provide an overview of child obesity surveillance systems globally, and to highlight main components and other types of survey data that can enhance our understanding of child obesity. Measures of adiposity, including body mass index and waist circumference are essential, but effective surveillance must also include measures of weight-related behaviours, including diet, physical activity, sedentary time, and sleep. While objective measures are desirable, the variability in psychometrics and rapid evolution of wearable devices is potentially problematic for examining long-term trends over time and how behaviours may change. Questionnaires on self-reported behaviours are often used but also have limitations. Because the determinants of obesity are not only functioning at the individual level, some measures of the broader environmental and commercial determinants, including the built and food environments, are useful to guide upstream policy decisions.

Children and young people’s body mass index measures derived from routine data sources: A national data linkage study in Wales

“…Widening inequalities exacerbate this trend with the most socioeconomic deprived populations disproportionately affected with higher prevalence of obesity [2]. Population-based overweight and obesity monitoring/surveillance systems are critical for monitoring trends in childhood obesity and related behaviours to inform obesity planning strategies and to determine the overall effect of specific government or other public health initiatives [3].…”

Can we estimate the causal effects of diet and sedentary behavior on schoolchildren’s overweight/obesity from observational studies?

“…While randomized controlled trials (RCTs) continue as a gold standard for causal inference, observational studies are more suitable for monitoring and tracking, both of which allow rapid adjustments in policy recommendations, regulations, and other interventions to improve nutritional health. With the advent of computerized evaluations of diet and PA by questionnaires, the cost-effectiveness of these methods has made them popular worldwide [1]. Reproducibility, internal, and (more rarely) external validity for some of these instruments have been reported, but to the best of my knowledge, their validity for causal inference on nutritional status has not been evaluated.…”