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KSR Number: KSRA229

A systematic review investigating interventions that can help reduce consumption of sugar-sweetened beverages in children leading to changes in body fatness

Risk of Bias Assessment

Overall summary: High risk of bias in the review

Bottom Line

Current evidence suggests that programs focussed on school-based education, school-delivered drinks and home-delivered drinks in particular may reduce the consumption of sugar-sweetened beverages and bodyweight. However, these conclusions should be interpreted with caution, since several methodological weaknesses mean relevant studies may have been missed, and reviewer error and bias may have been present. More rigorous studies are needed to support this evidence and help design more effective interventions to assist in addressing childhood obesity.

Risk of Bias Assessment

Overall summary High risk of bias in the review

High

Restrictions were applied based on date and langauge, meaning relevant studies may have been missed. While only studies with ≥6 months duration, and with >100 children were included, this was considered appropriate. Study selection was carried out by a single reviewer. No information was provided on the number of reviewers involved in data extraction or quality assessment, meaning that error and bias cannot be ruled out.

A. Did the interpretation of findings address all of the concerns identified in Domains 1 to 4? No
B. Was the relevance of identified studies to the review's research question appropriately considered? Probably yes
C. Did the reviewers avoid emphasizing results on the basis of their statistical significance? Probably yes
Risk of bias in the review High

Details of Review

Number of studies 8
Number of participants 5199
Last search date August 2013
Review type Intervention
Objective To review the evidence on interventions aimed at helping reduce the consumption of sugar-sweetened beverages in children; and assessing whether these interventions lead to subsequent changes in body fatness.
Population Healthy children (aged 2 to 18 years) who are at a healthy weight, overweight or obese.

Only studies including ≥ 100 children were included.
Interventions Any interventions focussed on reducing consumption of sugary drinks that are applied for ≥ 6 months.
Comparator Any control comparison treatments
Outcome Change in consumption of sugar-sweetened beverages; change in body composition indicative of body fatness (such as change in body mass index (BMI) from baseline, percentage overweight or obese, risk of being overweight, skinfold thickness or waist circumference).
Study design Not pre-specified. Final includes were all randomised trials.

Cross-sectional studies were excluded.

Results

Interventions were classified under four categories: school-based educational programmes, school-based educational programme combined with environmental changes, school-distributed drinks and home-delivered drinks.

In terms of school-based educational programmes, one study reported a numerical reduction (25%) in the number of glasses of carbonated drinks containing sugar consumed over a 3-day period after a primary school-based educational intervention compared to a control group, and reported a mean difference in the percentage of overweight or obese children of 7.7% (95% confidence interval [CI] 2.2 to 13.1%; 1 study, n=644 children). One study that used an intervention to encourage water consumption instead of sugar-sweetened beverages [SSBs] reported a significant decrease in the mean daily intake of carbonated drinks (1 study, n=1140 children). One study reported that an educational and environmental health-promoting intervention significantly reduced SSB consumption at 8 months (25.5% vs. 23.9%; 1 study, n=1108 children). One study delivered nine nutrition education sessions and reported a numerical reduction in the daily frequency of SSB consumption (-0.2 vs. -0.08) but no change in body mass index [BMI] gain (1 study, n=559 children). One study used a web-based computer-tailored intervention and reported a 0.54 lower odds of a high daily intake of SSBs compared to the control group (1 study, n=883 children).

In terms of school-based educational programmes combined with environmental changes, one study provided water fountains and water bottles together with performing educational sessions on water delivered by teachers as part of the school curriculum. While this study reported no effect on soft drink or juice consumption, water consumption was reported to be significantly increased compared to the control group (1.1 glasses per day, 95% CI 0.7 to 1.4 glasses per day; 1 study, n=2950 children).

In terms of school-delivered drinks, one study provided participating children with a masked replacement of SSBs with non-energy drinks for 18 months in primary school children. This study reported significant reductions in BMI Z-score, mean weight gain and body fat measurements for the intervention compared to control group (BMI z-score: -0.13; mean difference in weight gain: -1.01 kg; 1 study, n=641 children).

In terms of home-delivered drinks, one study delivered water or diet drinks to the homes of randomly assigned overweight or obese secondary-school children over a 12-month period. At 12 months, consumption of SSBs was reported to be almost non-existent (88% reduction in servings/week) and remained very low at 2 years (76% reduction) despite no active intervention in the intervening 12 months. BMI was also reported to be significant reduced for the intervention compared to control groups (BMI -0.57; 1 study, n=224 children).

Full Risk of Bias Assessment

The study objectives and eligibility criteria were clearly described. Studies were restricted based on year (only studies published after the year 2000 were included) and language (only English studies were included). Only trials with ≥6 months duration of therapy, and with ≥100 children were included; these were considered appropriate for the review.

1.1 Did the review adhere to pre-defined objectives and eligibility criteria? Probably yes
1.2 Were the eligibility criteria appropriate for the review question? Probably yes
1.3 Were eligibility criteria unambiguous? Probably yes
1.4 Were all restrictions in eligibility criteria based on study characteristics appropriate (e.g. date, sample size, study quality, outcomes measured)? No
1.5 Were any restrictions in eligibility criteria based on sources of information appropriate (e.g. publication status or format, language, availability of data)? No
Concerns regarding specification of study eligibility criteria High

Web of Science, Medline and EMBASE databases were searched for relevant studies. No additional searches were conducted to obtain possible relevant articles. A full search strategy was not reported, so it was not possible to assess how well searching was conducted. Searches were restricted by date (from January 2000 to August 2013). No restrictions were applied based on publication format. Only studies in English language were selected. Title screening was carried out by a single reviewer, and a second reviewer consulted at the abstract screening stage, and a third reviewer was involved in the full paper screening process.

2.1 Did the search include an appropriate range of databases/electronic sources for published and unpublished reports? Probably yes
2.2 Were methods additional to database searching used to identify relevant reports? No
2.3 Were the terms and structure of the search strategy likely to retrieve as many eligible studies as possible? No information
2.4 Were restrictions based on date, publication format, or language appropriate? No
2.5 Were efforts made to minimise error in selection of studies? No
Concerns regarding methods used to identify and/or select studies High

No information was provided on the number of reviewers involved in data extraction. Sufficient characteristics were available for the interpretation of the results. Study results were collected for the synthesis. The quality of the included studies was assessed using the Jadad scale. No information was provided regarding the number of reviewers involved in quality assessment.

3.1 Were efforts made to minimise error in data collection? No information
3.2 Were sufficient study characteristics considered for both review authors and readers to be able to interpret the results? Probably yes
3.3 Were all relevant study results collected for use in the synthesis? Probably yes
3.4 Was risk of bias (or methodological quality) formally assessed using appropriate criteria? Probably yes
3.5 Were efforts made to minimise error in risk of bias assessment? No information
Concerns regarding methods used to collect data and appraise studies Unclear

All studies appeared to be included in the review. The analysis methods were not pre-defined in the review, therefore it was not possible to assess if these were subsequently reported appropriately. Narrative synthesis was performed; this was considered appropriate. The quality of the included studies was not appropriately considered in the synthesis.

4.1 Did the synthesis include all studies that it should? Probably yes
4.2 Were all pre-defined analyses reported or departures explained? No information
4.3 Was the synthesis appropriate given the degree of similarity in the research questions, study designs and outcomes across included studies? Probably yes
4.4 Was between-study variation minimal or addressed in the synthesis? Probably yes
4.5 Were the findings robust, e.g. as demonstrated through funnel plot or sensitivity analyses? Probably yes
4.6 Were biases in primary studies minimal or addressed in the synthesis? Probably yes
Concerns regarding synthesis and findings Unclear

Abstract

BACKGROUND: Both the prevalence of childhood obesity and the consumption of sugar-sweetened beverages (SSBs) have increased globally. The present review describes interventions that reduce the consumption of SSBs in children and determines whether this leads to subsequent changes in body fatness. METHODS: Three databases were searched from 2000 to August 2013. Only intervention control trials, 6 months in duration, which aimed to reduce the consumption of SSBs in 100 children aged 2-18 years, and reporting changes in body fatness, were included. The quality of selected papers was assessed. RESULTS: Eight studies met inclusion criteria. Six interventions achieved significant (P 0.05) reductions in SSB intake, although this was not always sustained. In the two interventions providing replacement drinks, significant differences in body mass index (12- or 18-month follow-up) were reported (P = 0.001 and 0.045). The risk of being overweight/obesity was reduced (P 0.05) in three of the five education programmes but in one programme only for girls who were overweight at baseline and in one programme only for pupils perceived to be at greater risk at baseline. In the one study that included both provision of water and education, the risk of being overweight was reduced by 31% (P = 0.04) in the intervention group. CONCLUSIONS: The evidence suggests that school-based education programmes focusing on reducing SSB consumption, but including follow-up modules, offer opportunities for implementing effective, sustainable interventions. Peer support and changing the school environment (e.g. providing water or replacement drinks) to support educational programmes could improve their effectiveness. Home delivery of more suitable drinks has a big impact on reducing SSB consumption, with associated reductions in body weight.Copyright © 2014 The Authors. Journal of Human Nutrition and Dietetics published by John Wiley Sons Ltd on behalf of British Dietetic Association.