Sodium Intake in the U.S.: Evidence From Scanner Data

Abstract

Diet quality can be improved via two factors: healthier product offerings by food manufacturers and healthier purchasing habits of consumers. In this paper, we take a closer look at sodium, a food constituent identified as an important determinant of several acute health problems. In 2009, food manufacturers in the U.S. voluntarily committed to substantial reductions in sodium content through a self-regulatory process known as the National Salt Reduction Initiative (NSRI). The NSRI set sodium reduction targets for 2012 and 2014, where the targets were based on a sales-weighted average of the sodium content across products. While the existing evidence suggests that the NSRI was partially successful in reducing sodium intake, a limitation of using a sales-weighted measure as a metric is that it conflates two effects: reformulation efforts by food manufacturers (the focal point of the initiative) and changes in consumer purchasing behavior. In this paper, we use UPC-level nutrition data on the near-universe of all packaged food products in the U.S. over 2007-2015 to quantify each effect. We find that the two effects exerted strikingly opposing forces, nearly canceling each other out: while reformulation efforts contribute to a 53% reduction in sodium intake, the changes in consumer shopping behavior increase the intake by 48.3%. Furthermore, our results show that lower income households as well as ethnic and racial minority groups experience the smallest sodium reductions. The results suggest that policy interventions towards reducing the sodium intake should focus on altering consumer behavior, especially in vulnerable populations.