An online-based intervention to promote healthy eating through self-regulation among children: study protocol for a randomized controlled trial

BACKGROUND: Despite the enormous investment governments allocate to fight obesity, its worldwide prevalence is still on the rise. Moreover, the majority of the programs implemented are still targeting adults struggling with overweightness and focusing on transmitting knowledge about food. However, research shows that obesity prevention is more efficacious and cheaper, and beliefs about healthy eating have a stronger influence on eating behavior than declarative knowledge about food. In fact, knowledge about healthy eating only influences weight status when combined with self-regulation competences. Thus, the main goal of the current project is to develop and evaluate the efficacy of an online preventive intervention program, the HEP-S. This program is designed to promote and develop a set of transversal skills and strategies, related to self-regulation, on the healthy eating domain among school-aged children. METHODS: A three-armed randomized controlled trial will be conducted in several schools in Portugal. It will include a standard control group, with no intervention; an online intervention group, with the program for 20 weeks; and an enhanced online intervention group, with the program for 20 weeks embedded with gamification strategies throughout the program. Per research group, 40 groups of about 15 children each will be recruited and measured at five different time points. The three research groups will complete the same assessment protocol at the same timings (baseline, post-intervention, and 3, 6, and 9 months’ follow-ups). The assessment protocol will include anthropometric and psychological measures. The primary outcome measures will be the development of self-regulation skills for healthy eating over time, the development of self-efficacy attitudes, knowledge about healthy eating over time, and others. The secondary outcome measures will include the effect of gamification strategies, engagement, and satisfaction with the program, among others. The program will comprise the following: (i) a weekly group synchronous videoconference session with a trained educational psychologist serving as a mediator and (ii) a weekly parental involvement activity. Narratives, or story-tools, embedded with self-regulation strategies are at the core of the intervention. DISCUSSION: The program may play an important role in preventing risky and unhealthy eating behaviors by focusing on the development of self-regulation skills and strategies among elementary school children. TRIAL REGISTRATION: ClinicalTrials.gov NCT04099498. Registered on 23 September 2019.