Evaluating the relative impact of multiple healthy food choice interventions on choice process variables and choices.

Fiscal tools-taxes and/or subsidies-are increasingly used to address diet-related health problems. However, some studies have found that these tools are markedly more effective if attention is drawn to the tax or subsidy, suggesting that the price change alone may go unnoticed in the complex food environments that consumers face. Interventions that prompt individuals to consider health during choice show promise for promoting healthy food choices in both simple laboratory settings and complex, real-world markets. In this pre-registered study, I examine the impact of dietary fiber health prompts and/or dietary fiber subsidies on the per-serving fiber content of foods chosen, the documented set of products considered, and (self-reported) nutrition information use by participants in an online supermarket setting. Participants were randomized to one of four conditions: 1) control, 2) subsidy, 3) fiber prompt, and 4) fiber prompt + subsidy. Results show that both the prompt and prompt + subsidy conditions significantly increase fiber content of foods chosen (with the latter having a larger effect). While all three interventions influence the probability of using nutrition information during food choice and affect the set of products that respondents consider relative to the control condition, the effects were larger for the prompt and prompt + subsidy conditions. A multiple mediation analysis illustrates that both direct and indirect (through the set of products considered and the use of fiber information during choice) pathways lead to the significant overall increase in fiber content of selected foods.