Developing a Scale to Visually Evaluate BMI from Twitter Profile Pictures

Julia Morris, University of Washington
Stephanie Carson, University of Washington
Alina Arseniev, University of Washington
Gilad Amitai, University of Washington
Ali Shojaie, University of Washington

Data from social media networks, and Twitter in particular, are a promising new source for research on the social determinants of behaviors related to obesity. Up to this point, a major limitation has been difficulty in obtaining objective measures of body mass index (BMI) from Twitter users. In this paper, we develop a scale for visual estimation of BMI from Twitter profile photos. The scale uses reference Twitter images with known BMI information and asks coders to place photos of users with unknown BMI in the BMI category that most closely matches the photos. We describe an experimentation plan for refining this scale and present preliminary results from pretesting.