A systematic review of how researchers characterize the school environment in determining its effect on student obesity

Abstract

BackgroundObesity in early childhood is a robust predictor of obesity later in life. Schools provide unparalleled access to children and have subsequently become major intervention sites. However, empirical evidence supporting the effectiveness of school-based interventions against childhood obesity is of limited scope and unknown quality. The aim of this systematic review is to critically assess how researchers have characterized the school environment in determining its effect on childhood weight status in order to improve the quality and consistency of research in this area. We conducted a narrative review with a systematic search of the literature in line with PRISMA guidelines (2009). Original peer-reviewed research articles in English were searched from Medline, EMBASE, CENTRAL, CINAHL and PsycINFO databases from earliest record to January 2014. We included empirical research that reported at least one measure of the primary/elementary school environment and its relationship with at least one objective adiposity-related variable for students aged 4–12 years. Two authors independently extracted data on study design, school-level factors, student weight status, type of analysis and effect.ResultsFive studies met the inclusion criteria. Each study targeted different parts of the school environment and findings across the studies were not comparable. The instruments used to collect school-level data report no validity or reliability testing.ConclusionsOur review shows that researchers have used instruments of unknown quality to test if the school environment is a determinant of childhood obesity, which raises broader questions about the impact that schools can play in obesity prevention.

Regional survey supports national initiative for ‘water‐only’ schools in New Zealand

“…A systematic review of school environment changes found a limited evidence base (only UK and US studies), but these showed potential to improve health 11 . Another review found that there was a lack of evidence to show that the school environment determined obesity, but there was also a lack of validated tools to assess the school environment 12 . A review of school policies that limit access to sugary drinks and energy dense foods found mixed, but generally supportive, evidence for these policies in preventing obesity 13 .…”

“…11 Another review found that there was a lack of evidence to show that the school environment determined obesity, but there was also a lack of validated tools to assess the school environment. 12 A review of school policies that limit access to sugary drinks and energy dense foods found mixed, but generally supportive, evidence for these policies in preventing obesity. 13 For example, sales restriction at school had only limited effect on high school students' overall consumption of sugary drinks in Maine, 14 but was effective in Boston.…”

School‐level factors associated with obesity: A systematic review of longitudinal studies

“…The school setting has been recognized as an important intervention venue for obesity prevention because children and adolescents spend a significant amount of time in schools and share the surrounding environment that might influence their energy balance‐related behaviours, including diet and physical activity . Overall, school‐based obesity prevention programmes have been found to be most effective when they are theory‐based, behaviourally focused, long‐term (1‐4 years), include multicomponents such as parent involvement, and when the school environment and policy modifications are incorporated within the intervention programmes …”

“…Possible reasons for the limited success rates on obesity outcomes may vary but might include lack of methodological rigour including small number of schools, short‐term follow‐ups, lack of multicomponent strategies, and inconsistent intervention implementation. In addition, studies can be underpowered if there are high school‐level clustering effects in obesity outcomes that are not taken into account in the study design . Previous studies have shown considerable between‐school variation in obesity outcomes as well as behaviours related to energy balance .…”

Development and reliability of an audit tool to assess the school physical activity environment across 12 countries

“…The school built environment can be measured using surveys or objective methods to identify features that influence these behaviors. [10][11][12][13][14][15][16][17] Although surveys of school personnel are arguably easier to employ and are currently included as a component of several studies, 18 they can be burdensome for school staff, which may result in incomplete data, and may be subject to biased and/or incomplete reporting of school amenities. Objective assessments (often termed as 'audits') of the school built environment by study staff, on the other hand, pose little-to-no burden on school personnel and result in complete and verified data for all schools.…”