SSB taxes and diet quality in US preschoolers: estimated changes in the 2010 Healthy Eating Index.

BACKGROUND: Taxing sugar-sweetened beverages (SSBs) has been proposed as a strategy to combat child obesity. Yet it is unclear how a tax on SSBs might influence the overall quality of diet in preschool children. Thus, we use simulated price increases and the 2010 Healthy Eating Index (HEI-2010) to explore the relationship between SSB taxes and diet quality in preschool children. METHODS: Price and purchase data from the 2009-2012 Nielsen Homescan Panel and a two-part marginal effects model were used to estimate relative changes in purchases with a 20% increase in the price of SSBs. Demand elasticities were applied to dietary intake data for children ages 2-5 years from the National Health and Nutrition Examination Survey (2009-2010 and 2011-2012) to estimate the impact of a 20% SSB tax on dietary intake and quality (HEI-2010). RESULTS: A 20% increase in the price of SSBs was associated with lower total caloric intake (-28 kcal d-1 , p < 0.01), caloric intake from juice drinks (-20 kcal d-1 , p < 0.01), added sugars (-4.1 servings d-1 , p = 0.03), refined grains (-0.63 servings d-1 , p < 0.01) and total meat (-0.56 servings d-1 , p < 0.01). Beneficial decreases in empty calories and refined grains were offset by unfavourable changes in fatty acid profile, total protein, vegetables and fruit, such that total HEI scores (0-100 range) were not meaningfully changed with a 20% increase in SSB price (difference: -0.85, p < 0.01). CONCLUSIONS: A 20% tax on SSBs could decrease caloric intake, and intakes of added sugars and SSBs, but may not improve diet quality as an isolated intervention among US preschool children.