Reducing Young Schoolchildren’s Intake of Sugar-Rich Discretionary Foods and Drinks: Findings from the cluster-randomised intervention study “Are You Too Sweet?”

Danish children’s consumption of sugar-rich foods and drinks is much higher than the recommended. High intake of added sugars has been associated with various adverse health outcomes, including an elevated risk of obesity, poor dental health, and a range of non-communicable diseases. Given that children’s consumption of added sugars escalates throughout school years, and dietary behaviours often persist into adulthood, it becomes imperative to implement preventative measures from early childhood. The primary sources of added sugar in children predominantly stem from energy-dense, nutrient-poor foods, such as cakes, confectionery, sweetened beverages, and snacks. These food items fall outside a healthy dietary pattern and are thus classified as discretionary. Despite many parents striving to provide their children with a nutritious diet, many remain unaware of the appropriate limits of these foods.

In 2019, the “Are You Too Sweet?” project was launched to reduce the consumption of sugar-rich discretionary foods and drinks among children and guide Danish families toward a healthier dietary pattern. The project involved formulating guidelines and tools, which were subsequently to be tested on 100 families with young school-age children. The present thesis constitutes a part of the scientific evaluation of this project. This thesis aims to assess the effectiveness of the intervention study “Are You Too Sweet?” in decreasing the intake of sugar-rich discretionary foods and drinks among children. Additionally, the study aims to analyse the parental practices and theoretical constructs that potentially mediated these changes.

The study was designed as a 3.5-month cluster-randomised, non-blinded, controlled, parallel intervention trial. Six schools in the Danish municipality, Hvidovre, were randomly assigned to either an intervention group (n = 4) or a control group (n = 2). Families with children planned to start at one of the six schools were eligible for participation. In the spring of 2020, school dentists in Hvidovre invited families to participate in the study. During the autumn of 2020, 153 children aged five to seven years were enrolled in the study.

The local school health nurse executed the intervention as an extension of the standard care provided to all Danish preschool class children (0th grade). Families in the intervention group documented their child’s consumption of sugar-rich discretionary foods and beverages using a brief registration tool, which provided an estimate of weekly intake. This estimate was then shared with the school health nurse at the regular school health nurse consultation, leading to personalised guidance on discretionary consumption. Families were also given a box with various materials for use at home, including an AR app, and invited to a Facebook group.

The families in the intervention and control groups registered their child’s full diet by a seven-day dietary record before and after the intervention. Furthermore, parents responded to a questionnaire before and after the intervention, including questions about parental practices, norms, attitudes, and self-efficacy. Linear mixed regression models were used to evaluate dietary changes in Paper II, and statistical mediation analysis was used to explore mediators from the questionnaire in Paper III.

Results from Paper II found no significant changes in the intake of sugar-rich discretionary foods and drinks compared to the control group following the intervention. However, discretionary drinks were reduced significantly by 41% compared to the control group, and a significant decrease in discretionary foods and drinks intake during weekend days was further found. Supplementary analysis of the thesis found that the reduction depended on parental education level, suggesting changes mainly for children of parents with lower education levels. Paper III expanded on this by revealing that a shift in parental norms and attitudes regarding discretionary consumption reserved for special occasions mediated a decreased child sugar intake.

Reflected in the theoretical development, use of materials, and qualitative evaluation of the intervention “Are You Too Sweet?” this thesis demonstrates the potential to increase awareness of sugar-rich discretionary foods and drinks. Limited effects of the intervention might be affected by the COVID-19 situation, although supplementary strategies or structural changes to reach larger effects might be necessary. Establishing normative benchmarks for acceptable consumption plays a pivotal role in health promotion strategies, especially considering the intricate landscape of food availability and marketing of unhealthy foods and drinks. Further, the school health nurses were found to have a pivotal role in the intervention, both as they functioned as a trusted authority and were essential for making the intervention implementable.