Increasing water intake of children and parents in the family setting: a randomized, controlled intervention using installation theory

Children and adults in developed countries on average consume too little water, which can lead to negative health consequences. In a one-year longitudinal field experiment in Poland, we compared the impact of three home-based interventions on helping children and their parents/carers to develop sustainable increased plain water consumption habits. Fluid consumption of 334 children and their carers were recorded over one year using on-line specific fluid dietary record. They were initially randomly allocated to three conditions: Control, Information (child and carer received information on the health benefits of water), Placement (in addition to information, free small bottles of still water for a limited time period were delivered at home). After three months, half of the non-controls were randomly assigned to Community (child and carer engaged in an on-line community forum providing support on water consumption). All conditions significantly increased water consumption of children (by 219-567%) and adults (by 22%-89%). Placement + Community generated the largest effects. Community enhanced the impact of Placement for children and parents, and the impact of Information for parents but not children. The results suggest that the family setting offers considerable scope for successful installation interventions encouraging children and carers to develop healthier consumption habits, in mutually reinforcing ways. Combining information, affordances, and social influence gives the best, and most sustainable, results.