Importance: Tax evaluations have shown effectiveness in reducing purchases of taxed items. However, few studies have looked at changes in overall dietary intake according to national surveys.
Objective: To estimate the contribution of taxed and untaxed beverages and foods to dietary intake over time, and the nutritional dietary profile in total beverages and foods consumed.
Design, setting, and participants: This cross-sectional study used data from 3 National Health and Nutrition Surveys of a nationally representative sample of participants aged older than 1 year in Mexico from 2012 (pretax), 2016, and 2018 (posttax). Data were analyzed from September 2021 to December 2022.
Exposure: Taxes on sugar-sweetened beverages and nonessential energy-dense foods implemented since 2014.
Main outcomes and measures: The outcomes were the contribution of taxed and untaxed beverages to total beverage volume, the contribution of taxed and untaxed foods to total food energy, and the energy density and content of added sugars and saturated fats. Outcomes were assessed with 24-hour recalls (24HR) (2012 and 2016) and Food Frequency Questionnaires (FFQ) (2012, 2016, and 2018), and were adjusted by sociodemographic and macroeconomic variables.
Results: A total of 17 239 participants were analyzed from 2012, 18 974 from 2016, and 30 027 from 2018; approximately 50% were men, and approximately 75% lived in urban areas. According to 24HRs, the contribution of taxed beverages to total beverage volume changed -2.3 (95% CI, -4.4 to -0.2) percentage points from 2012 to 2016, while water increased. The contribution of taxed foods to total food energy changed -3.0 (95% CI, -4.2 to -1.8) percentage points, while untaxed whole grains, processed meats, other animal sources, and sugars and desserts increased. The content in total beverages of added sugars changed -1.1 kcal/100 mL (95% CI, -2.0 to -0.2), and in total foods, the content of added sugar changed -0.6 %kcal (95% CI, -1.0 to -0.2), saturated fat changed -0.8 %kcal (95% CI, -1.1 to -0.4), and energy density changed -9.8 kcal/100 g (95% CI, -13.8 to -5.8). Main results were consistent with the FFQ (up to 2018), with some differences in subgroups and nutritional components.
Conclusions and relevance: The findings of this study on 3 cross-sectional national dietary surveys are consistent with previous evaluations; after tax implementation, there was a decrease in the contribution of taxed items. Furthermore, some unhealthy untaxed items increased, but the content of unhealthful nutritional components, particularly added sugar, in overall beverages and foods decreased.