Harnessing the Small Victories: Goal Design Strategies for a Mobile Calorie and Weight Loss Tracking Application

We investigate the role of small victories, in the form of short-term goal achievements, on long-term health outcomes. Using novel large-scale data from a popular mobile calorie and weight management application, we track the daily health outcomes across a large number of users. The application sets a salient daily budget for calories, and by comparing cases in which the users are under versus over-budget, we document empirical patterns about the role of reference-dependence calorie consumption and future weight loss. Motivated by these patterns, we estimate a dynamic structural model of calorie consumption with reference-dependent utility and serial correlation to evaluate various hypothetical goal design schemes. First, we show that adaptive goal designs are more effective at encouraging disciplined calorie consumption than goal designs that are uniformly applied to all users. Second, our analysis of goal personalization reveals that users with high initial BMI may benefit the most from challenging goals. Third, we demonstrate that exposing users to a variety of means towards goal achievement may be worthwhile.