Abstract
INTRODUCTION: The objective of this study was to quantify changes in the affordability of sugar-sweetened beverages, a product implicated as a contributor to rising rates of obesity worldwide, as a function of product price and personal income. METHODS: We used international survey data in a retrospective analysis of 40 high-income and 42 low-income and middle-income countries from 1990 to 2016. Prices of sugar-sweetened beverages were from the Economist Intelligence Unit's World Cost of Living Survey. Income and inflation data were from the International Monetary Fund's World Economic Outlook Database. The measure of affordability was the average annual percentage change in the relative-income price of sugar-sweetened beverages, which is the annual rate of change in the proportion of per capita gross domestic product needed to purchase 100 L of Coca-Cola in each country in each year of the study. RESULTS: In 79 of 82 countries, the proportion of income needed to purchase sugar-sweetened beverages declined on average (using annual measures) during the study period. This pattern, described as an increase in the affordability of sugar-sweetened beverages, indicated that sugar-sweetened beverages became more affordable more rapidly in low-income and middle-income countries than in high-income countries, a fact largely attributable to the higher rate of income growth in those countries than to a decline in the real price of sugar-sweetened beverages. CONCLUSION: Without deliberate policy action to raise prices, sugar-sweetened beverages are likely to become more affordable and more widely consumed around the world.