Decreasing consumption of sugar-sweetened beverages and Raising tap water consumption through Interventions based on Nutrition and sustainability for Kids: study protocol of the "DRINK" cluster randomised controlled trial

BACKGROUND

Effectiveness of actions to reduce sugar-sweetened beverage (SB) consumption in children still needs to be improved. Furthermore, the growing concern about sustainable food systems encourages to develop sustainability-based interventions. The objective of this cluster randomised controlled trial is to evaluate the long-term effectiveness of nutrition- and environmental sustainability-based interventions on the reduction in SB intake and on the increase in tap water consumption in 3rd to 6th grade primary school children (8 to 11 years of age).

METHODS

Forty-eight French-speaking Belgian primary schools (equivalent to around 3500 pupils involved in the evaluation) are randomised using a factorial plan: (i) control, (ii) nutrition-based intervention, (iii) sustainability-based intervention, and (iv) both. The interventions (encouragement of water breaks; provision of posters, leaflets, reusable cups, and glass bottles; website; meetings at school) were undertaken from February 2022 to June 2023. Evaluation includes questionnaires for the children and their parents on various determinants of dietary behaviour, a 4-day diary to collect information on the child's beverage consumption, and audits at schools. The first evaluation was conducted in Spring 2021 before any intervention, with the two post-intervention evaluations being held in 2022 and 2023. The main quantitative judgement criterion will be the change over time in the mean SB consumption (in ml/day) in the intervention groups compared with the control group. Given the context of the research (school), the safety of the intervention, and the content of data collection, a consent was acknowledged as unnecessary by the Ethical Committee of the Faculty of Psychology (ULB; n°073/2021), but children and parents are explicitly informed of their right to refuse to fill in the questionnaires.

DISCUSSION

Multicomponent interventions based on nutrition and on environmental sustainability, alone or mixed, will provide an original and topical insight into health promotion at school around dietary behaviours. The dissemination plan will enable to widely inform stakeholders, school staff, and families, in addition to the scientific community through the usual medium (articles, conferences), about the research findings in 2024-2025.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN99843102. Retrospectively registered on 25 May 2021.

Tax on sugary drinks and trends in daily soda consumption by family affluence: an international repeated cross-sectional survey among European adolescents

BACKGROUND

The WHO recommends soda taxes to reduce sugar consumption, but the effect across socioeconomic groups is unclear.

OBJECTIVES

We assessed 16-y trends in daily soda consumption among adolescents in 4 European countries with a soda tax and 5 comparison countries, by family affluence.

METHODS

Five rounds of the international "Health Behaviour in School-Aged Children" school-based survey were used (school years 2001/2002 to 2017/2018, repeated cross-sectional design). Finland, France, Belgium, and Portugal introduced or updated a soda tax during this period. For comparison, we selected 5 neighboring countries without such a tax. Nationally representative samples of adolescents aged 13 and 15 y (n = 165,521; 51.2% girls) completed a standardized questionnaire, including a question on soda consumption frequency. Using the family affluence scale (FAS), we categorized adolescents into lower-, middle- or higher-affluent groups. Changes in daily soda consumption were assessed in each country independently.

RESULTS

Before taxation, daily soda consumption was more likely among lower-affluent adolescents in France and Belgium (P < 0.001, socioeconomic inequalities) and was similar across FAS groups in Finland and Portugal (no inequalities). After the tax, daily soda consumption was reduced across all FAS groups in Finland, Belgium, and Portugal (P_interactions ≥ 0.33). In France, a posttax decrease was observed only among lower-affluent adolescents (OR_lower, 0.76; 95% CI: 0.60, 0.96; reduced inequalities). During the same periods, socioeconomic patterns remained stable in 3 comparison countries (P_interactions ≥ 0.38), and larger reductions in daily soda consumption were observed among middle- or higher-affluent adolescents compared with lower-affluent adolescents in the remaining 2 comparison countries (P_interactions ≤ 0.08, increased inequalities).

CONCLUSIONS

Socioeconomic patterns did not change after the tax implementation in 3 out of 4 countries, and socioeconomic inequalities were reduced in France. Taxing sodas might be an effective measure to attenuate, or at least not exacerbate, socioeconomic inequalities in adolescent daily soda consumption. Am J Clin Nutr 20XX;xx:xx-xx.

Sixteen-year trends in adolescent consumption of sugar-sweetened soda in six European countries with a soda tax and comparison countries: a repeated cross-sectional survey analysis

OBJECTIVE

To examine changes in the proportions of daily, weekly and occasional consumers of sugar-sweetened soda in six European countries that introduced/updated a tax between 2001-2002 and 2017-2018 and in neighbouring comparison countries (without a tax).

DESIGN

Repeated cross-sectional surveys.

SETTING

Health Behaviour in School-aged Children study, spanning five survey years (school years 2001-2002 to 2017-2018).

PARTICIPANTS

Nationally representative samples of 13-year- and 15-year-old adolescents (n 236 623, 51·0 % girls).

RESULTS

Tax sizes (€0·02/l to €0·22/l) and pre-tax soda consumption were heterogeneous across countries. Prevalence of daily soda consumption reduced in the survey year following tax implementation in Latvia (from 17·9 to 11·9 %, P = 0·01), Finland (4·2 to 2·5 %, P = 0·001), Belgium (35·1 to 27·8 %, P < 0·001) and Portugal (17·4 to 14·9 %, P = 0·02), but not in Hungary (29·8 to 31·3 %, P = 0·47) or France (29·4 to 28·2 %, P = 0·27). However, reductions were similar (Finland) or smaller (Belgium, Portugal) than those in the comparison countries, except in Latvia where the reduction was larger (Pinteraction < 0·001). Prevalence of weekly soda consumption remained stable (Finland, Hungary and France) or increased (Latvia, Belgium); only Portugal experienced a decline (P < 0·001), which was larger than in the comparison country (Pinteraction < 0·001). Prevalence of occasional soda consumption (<1x/week) did not rise after implementation of the tax in Latvia, Finland, Hungary, France or Belgium, or the rise was similar to the comparison country in Portugal (Pinteraction = 0·15).

CONCLUSIONS

Countries with a soda tax did not experience larger beneficial changes in post-tax adolescent consumption frequency of soda than comparison countries. Further studies, with different taxation types, are needed in the adolescent population.

The cost of diets according to diet quality and sociodemographic characteristics in children and adolescents in Belgium

This study aims to estimate cost variations according to diet quality and sociodemographic characteristics in children. Data (n = 1,596; 5-17 y) from the Belgian National Food Consumption Survey were used. The "Kidmed index" and dietary patterns (DP) identified through principal component analysis were used to assess diet quality. Daily diet cost was estimated after linking the consumed foods with the GfK ConsumerScan panel food prices. The mean diet cost was 4.68€/day (SEM: 0.05). Adjusted for covariates and energy intake, the mean diet cost was 9.1% higher in the highest Kidmed adherence (vs. the lowest) and 6.2% higher in the tercile T3 (vs. T1) of the "Healthy" DP score. It was 4.8% lower in the T3 (vs. T1) for the "Junk food" DP score. Diet cost was higher in 12-17 year-olds (vs. 5-11 years) and in medium and high educated household (vs. the lowest). These findings support policies to make healthy diets more affordable.

Ten-year changes in diet quality among adolescents and young adults (Food Consumption Survey 2004 and 2014, Belgium)

PURPOSE

To estimate the 10-year change in the overall nutritional quality of adolescent and young adult's diet, as measured by the modified Nutrient Profiling System of the British Food Standards Agency individual Dietary Index (FSAm-NPS-DI) which funds the Nutri-Score development, and in different components of this score, overall and according to the individual characteristics.

METHODS

Two 24-h dietary recalls were carried out in 15- to 39-year-old respondents included in the Belgian Food Consumption Surveys in 2004 (n = 1186) and 2014 (n = 952). The weighted mean individual FSAm-NPS-DI was computed from all foods and beverages consumed, converted into a scale from 0 to 100 (from the poorest to the most favorable diet), and compared between survey years. Subject characteristics associated with the score, along with the mean daily intake of food groups, energy, and nutrients were explored in multiple linear regressions stratified by survey year and age group.

RESULTS

The weighted mean daily FSAm-NPS-DI significantly increased between 2004 and 2014 [2004: 55.3 (SEM: 0.2) vs. 2014: 57.4 (0.5), P < 0.001 in 15- to 18-year olds; 55.0 (0.6) vs. 58.1 (0.4), P < 0.001 in 19- to 25-year olds; 57.1 (0.4) vs. 58.5 (0.3), P < 0.01 in 26- to 39-year olds]. SFA intake decreased in all age groups, and sugar-sweetened beverage, sugar, sodium, and fiber intakes decreased among 15‒18-year olds. The nutritional quality changed unevenly according to sociocultural characteristics, levels of education and regions being the main sources of disparities.

CONCLUSION

The quality of diet improved overall between 2004 and 2014 among young people in Belgium, an uneven change that need to be confirmed in future surveys, following the implementation of the Nutri-Score.

The cost of diets according to nutritional quality and sociodemographic characteristics in Belgium

Introduction

Prices of foods may influence purchases and therefore, the overall quality of diets. Our objective was to estimate cost variations according to the nutritional quality of diets and to identify sociodemographic characteristics associated with the cost differences in adults' diets.

Methods

Data from adults (N = 1,158; 18-64 years) included in the 2014-2015 Belgian National Food Consumption Survey were used. Dietary assessment was based on two 24-h dietary recalls and a food frequency questionnaire. The “Mediterranean Diet Score” (MDS) and the “Healthy Diet Indicator” (HDI) were used to assess diet quality. Daily diet cost was estimated after linking the consumed foods with the 2014 GfK ConsumerScan panel food price data. Associations were estimated using linear regressions.

Results

The mean diet cost was 5.79€/day (SEM: 0.07). Adjusted for covariates and energy intake, it was significantly higher in the highest (T3) tercile of both scores than in the lowest tercile (T1) (MDS: T1=5.60€/d (0.09) vs. T3=6.03€/d (0.10); HDI: T1=5.42€/d (0.09) vs. T3=6.34€/d (0.10)). Higher intake of fruits, vegetables, fish, dairy products, vegetable oil, fibre and potassium and lower intake of free sugars were associated with higher diet cost. Both diet quality and cost were higher in 35-64-year-old (vs. 18-34 years), active (vs. students) and post-secondary education (vs. secondary education or lower) respondents. The association between quality and cost of diets was weaker in males and among individuals with higher education levels.

Conclusions

Healthier diets are more expensive than less healthy diets in Belgium. These findings contribute to a better understanding of social inequalities in diet in order to support public health policies and actions.

Key messages

Strategies need to be developed to improve the affordability to a healthy diet. In particular, messages promoting healthy diet targeted to the vulnerable populations should better consider the food cost.

Socioeconomic Disparities in Diet Vary According to Migration Status among Adolescents in Belgium

Little information concerning social disparities in adolescent dietary habits is currently available, especially regarding migration status. The aim of the present study was to estimate socioeconomic disparities in dietary habits of school adolescents from different migration backgrounds. In the 2014 cross-sectional “Health Behavior in School-Aged Children” survey in Belgium, food consumption was estimated using a self-administrated short food frequency questionnaire. In total, 19,172 school adolescents aged 10–19 years were included in analyses. Multilevel multiple binary and multinomial logistic regressions were performed, stratified by migration status (natives, 2nd- and 1st-generation immigrants). Overall, immigrants more frequently consumed both healthy and unhealthy foods. Indeed, 32.4% of 1st-generation immigrants, 26.5% of 2nd-generation immigrants, and 16.7% of natives consumed fish ≥two days a week. Compared to those having a high family affluence scale (FAS), adolescents with a low FAS were more likely to consume chips and fries ≥once a day (vs. <once a day: Natives aRRR = 1.39 (95%CI: 1.12–1.73); NS in immigrants). Immigrants at schools in Flanders were less likely than those in Brussels to consume sugar-sweetened beverages 2–6 days a week (vs. ≤once a week: Natives aRRR = 1.86 (95%CI: 1.32–2.62); 2nd-generation immigrants aRRR = 1.52 (1.11–2.09); NS in 1st-generation immigrants). The migration gradient observed here underlines a process of acculturation. Narrower socioeconomic disparities in immigrant dietary habits compared with natives suggest that such habits are primarily defined by culture of origin. Nutrition interventions should thus include cultural components of dietary habits.