School-Based Group Motivational Interviewing Shows Promise for Reducing Sugary Drink Consumption in Adolescents

What Is Group Motivational Interviewing and How Does It Work in Schools?

Motivational interviewing (MI) is a well-established, person-centered counseling method originally developed for addiction treatment. It works by exploring and resolving ambivalence about behavior change, drawing on the individual's own motivations rather than imposing external pressure. The DISS (Drinks in Secondary Schools) feasibility study, published in BMJ Public Health, adapted this technique for group delivery in school settings — a novel approach aimed at making the intervention scalable and cost-effective for public health use.

In the study, trained facilitators led group MI sessions with adolescents in East London secondary schools, focusing specifically on sugar-sweetened beverage (SSB) consumption. The sessions encouraged students to reflect on their drinking habits, discuss the health implications, and consider personal reasons for reducing intake. Researchers assessed whether the intervention could be delivered practically within the constraints of a school day and whether students found it engaging and acceptable — both critical questions before a larger randomized controlled trial could be justified.

Why Is Reducing Sugar-Sweetened Beverage Intake So Important for Young People?

Sugar-sweetened beverages remain one of the largest single sources of added sugar in young people's diets across the United Kingdom and globally. According to the World Health Organization, free sugar intake should be below 10% of total energy intake, with additional benefits seen below 5%. Despite public health campaigns and the UK Soft Drinks Industry Levy introduced in 2018, national dietary surveys consistently show that children and adolescents exceed recommended sugar limits, with SSBs contributing a substantial proportion of that excess.

The health consequences are well documented. High SSB consumption is associated with increased risk of obesity, insulin resistance, type 2 diabetes, cardiovascular disease, and dental caries. These associations are particularly concerning in adolescence, when dietary habits are being established that often persist into adulthood. Socioeconomic disparities compound the problem — young people in more deprived areas, such as parts of East London where the DISS study was conducted, tend to have higher SSB consumption. This makes school-based interventions especially relevant, as they can reach young people regardless of family income or home environment.

What Did the DISS Feasibility Study Find?

The DISS feasibility study was designed to answer practical questions about whether group MI could work in a real-world school environment before investing in a full-scale trial. Key outcomes included recruitment and retention rates, fidelity of intervention delivery, and qualitative feedback from participants and school staff. The researchers reported that the intervention was feasible to deliver within normal school operations and that students engaged positively with the group sessions.

Importantly, acceptability was high among both the young people who participated and the school staff who facilitated access. Participants reported that the non-judgmental, exploratory nature of MI felt different from typical health education, which often takes a more didactic approach. The findings suggest that group MI could be a promising, low-cost strategy for public health agencies seeking to reduce adolescent sugar consumption at scale. However, as a feasibility study, it was not designed to measure definitive changes in SSB intake — that would require a subsequent randomized controlled trial with larger sample sizes and longer follow-up periods.