Crystal Smit

Evaluation of the Motivation Process 5 95 promising effects of using self-determination theory-based techniques in social network interventions to motivate influence agents and, indirectly, their peers. BACKGROUND The prevalence of childhood overweight and obesity has increased at an alarming rate worldwide (WHO, 2020). The increasing consumption of sugar-sweetened beverages (SSBs) has been identified as a major contributor to these rising levels (Luger et al., 2017). The majority of children (61%) consume at least one SSBs on a given day with an average of 132.5 kcal/day (Bleich, Vercammen, Koma, & Li, 2018). Reducing the consumption of SSBs has proven to be an effective strategy to decreaseweight gain in children (Hu, 2013). Inparticular, replacing the consumption of SSBs with water seems to be a promising approach (Zheng, Rangan, et al., 2015). Unfortunately, data from several countries suggest that children’s daily water consumption is below recommended levels (Drewnowski et al., 2013; RIVM, 2019; Sui, Zheng, Zhang, & Rangan, 2016; Vieux et al., 2017). There is therefore a need for interventions aimed at promoting water consumption among children and thus reducing their SSBs consumption. However, recent evidence identifies that previous interventions have only had small positive effects on the water and SSB consumption of children (Vargas-Garcia et al., 2017). A promising method for interventions may be to incorporate the influence of the social environment in order to promote water consumption among children. There is sufficient evidence that the social environment strongly influences the consumption behavior of children (Cruwys et al., 2015; Herman, 2015; Higgs, 2015; Patrick & Nicklas, 2005). As children grow older, their susceptibility to peers increases, peaking during early adolescence (Steinberg & Monahan, 2007). Extensive systematic reviews have therefore also shown that peers play an important role in children’s food choice and intake (Salvy & Bowker, 2013; Salvy et al., 2012). For example, peers can establish a social guideline (i.e., social norm) on food choice and intake which can be followed by others (Stok et al., 2016). In social modelling studies, children also appear to directly adjust their intake to that of their table companions (Cruwys et al., 2015). Children also tend to consume more