A process evaluation of an adolescent weight management intervention: findings and recommendations

Process evaluation is valuable in guiding development of effective intervention programmes but rare in adolescent weight management. This paper presents a process evaluation of the Loozit(®) randomized controlled trial, a community-based behavioural lifestyle intervention for obese 13-16 year olds. Adolescents were randomized to receive the two-phase Loozit(®) group programme, with (n = 73) or without (n = 78), additional therapeutic contact (telephone coaching, short message service and/or emails) in Phase 2. Quantitative and qualitative process data were collected. Facilitators used a standardized evaluation form to document participant attendance, and comment on lesson adherence and process delivery. Adolescents and parents completed satisfaction questionnaires at 2-, 12- and 24-month follow-ups. Following the intervention, 14 adolescents who provided informed written consent were interviewed about their experience with additional therapeutic contact. Data were analysed using descriptive statistics, parametric and non-parametric tests to compare group means, and thematic analyses. Group attendance rates averaged 85 and 47% during Phases 1 (0-2 months) and 2 (3-24 months), respectively. Facilitators frequently noted that participants reported making healthy lifestyle changes. Elements enjoyed in the sessions included practical activities, fun active games, resistance training and forming new friendships. Adolescents struggled with setting specific, measurable, achievable, realistic and timely (SMART) goals. Overall, participants were satisfied with the help received including the telephone and electronic contact. More than 80% of participants found the programme changed adolescents' eating and physical activity habits, and 89% of parents reported changing parenting strategies. Future adolescent group-based programmes may enhance participant engagement and programme effectiveness by including more interactive and frequent telephone and electronic contact.