Crystal Smit

Social Network Intervention 2 27 BACKGROUND Childhood obesity is among the most serious public health problems in the 21st century (WHO, 2020). At present, 11% of European (CBS, 2012) and 17% of American children (Ogden, Carroll, Kit, & Flegal, 2012) are estimated to be overweight or obese. Beyond the increased risk of becoming obese as an adult, overweight children have a higher risk of developing physical problems such as diabetes and cardiovascular diseases (WHO, 2015). The consumption of sugar- sweetened beverages (SSBs) has been identified as a major contributor to the obesity epidemic (Hu, 2013). Approximately 66% of children consume at least one SSB per day (Han & Powell, 2013), which can lead to an additional weight gain of 6.75 kg in one year (Apovian, 2004). Research suggested that reducing SSB consumption may be an effective way to prevent children from becoming overweight or obese (Hu, 2013). Specifically, targeting SSB consumption by means of promoting water consumption—which has zero calories and can reduce cravings for SSBs—seems to be a promising approach (Hu, 2013). Unfortunately, several interventions that tried to stimulate water consumption have shown limited effects on changing children’s behavior (e.g., Loughridge & Barratt, 2005; Muckelbauer et al., 2009; Visscher et al., 2010). A possible explanation is that most health interventions focused on prevention strategiesonan individual level (Sharma, 2006), even though the social environment has been found to have a strong influence on people’s eating and drinking behavior (Cruwys et al., 2015; Emmons, Barbeau, Gutheil, Stryker, & Stoddard, 2007; Salvy et al., 2012). Especially among adolescents, social influence is an important factor in the initiation and maintenance of consumption behaviors (Patrick & Nicklas, 2005). Ample empirical studies have shown that children and adolescents adjust their intake to that of their table companions (Cruwys et al., 2015; Herman, Roth, & Polivy, 2003; Higgs, 2015). In children, social modeling studies have shown that peers can set a guideline or social norm in food choice and intake which is followed by others (see for review; Cruwys et al., 2015). Most of the social modelling studies have suggested implementing this knowledge into community or social network