Effects of interventions based on the theory of planned behavior on sugar-sweetened beverage consumption intentions and behavior.

There is increasing concern about the health risks of added dietary sugar, perhaps particularly when consumed in beverages that contain no essential nutrients (e.g., sodas). The purpose of this experiment was to examine the relative and combined efficacy of three interventions based on the theory of planned behavior (TPB) for motivating reductions in sugar sweetened beverage (SSB) consumption. Four-hundred-thirty undergraduates were randomised in a 2*2*2 factorial design. Participants received either information designed to increase awareness of the risks of SSB consumption or control information, and received either information about SSB consumption norms or no norms information, and either made plans to reduce their SSB consumption or engaged in a control planning task. Results demonstrated that the interventions, separately and in conjunction, resulted in greater intentions to reduce SSB consumption in the future, and there was evidence that these effects were mediated by the effects the interventions had on the TPB constructs. Further, the risks information resulted in more behaviors indicative of preparations to alter SSB consumption and those who engaged in the SSB planning task reported significantly lower SSB consumption at follow-up compared to controls. The three interventions utilized showed promise for altering SSB consumption intentions and behavior and, given their brevity and low cost, have potential to be developed into large scale community-based interventions that may lead to meaningful public health benefits.