Since 2006, New York City (NYC) has attempted to reduce sugary drink consumption through several population-based initiatives, media campaigns and policy proposals. We estimated trends in the relative market share of sugary drinks and other beverage categories in NYC, using over 5 years of weekly, point-of-sale data from a retailer sample. We used an interrupted time series approach to assess whether changes in NYC beverage purchasing patterns occurred following the announcement of a proposed portion cap rule for consumer purchases of sugary drinks. Overall, market share of sugary drinks declined in NYC between 2010 and 2015. While the proportion of beverage volume sold that was sugary drinks was stable prior to the May 2012 portion cap rule announcement, decreases of 1.25% per year were observed in the period following the announcement compared to the period before (95% confidence interval (CI) - 1.60, - 0.90). Water/seltzer market share was increasing prior to the announcement and increased by an additional 1.03% per year in the post-announcement period (95% CI 0.48, 1.57). City-led efforts to increase public awareness about sugary drink-associated health risks in NYC may have led to reductions in consumer purchases of these beverages. Though never implemented, the portion cap proposal and accompanying media coverage may have contributed to decreases in sugary drink sales.
Keywords: Consumer behavior; Food policy; Interrupted time series analysis; New York City; Portion cap rule; Sugary drinks.