Sodium Reduction in US Households' Packaged Food and Beverage Purchases, 2000 to 2014

Abstract

Importance: Initiatives to reduce sodium in packaged foods have been launched in the United States, yet corresponding changes in the amount of sodium that US households obtain from packaged foods have not been evaluated, to our knowledge.

Objective: To assess 15-year changes in the amount of sodium that US households acquire from packaged food purchases, the sodium content of purchases, and the proportion of households that have purchases with optimal sodium density.

Design, setting, and participants: Longitudinal study of US households in the 2000 to 2014 Nielsen Homescan Consumer Panel, a population-based sample of households that used barcode scanners to record all packaged foods purchased throughout the year. Time-varying brand- and product-specific nutrition information was used for 1 490 141 products.

Main outcomes and measures: Sociodemographic-adjusted changes in mean sodium per capita (mg/d) and sodium content (mg/100 g), overall and for top food group sources of sodium, and the proportion of households that have total purchases with sodium density of 1.1 mg/kcal or less.

Results: In a nationwide sample of 172 042 US households (754 608 year-level observations), the amount of sodium that households acquired from packaged food and beverage purchases decreased significantly between 2000 and 2014 by 396 mg/d (95% CI, -407 to -385 mg/d) per capita. The sodium content of households' packaged food purchases decreased significantly during this 15-year period by 49 mg/100 g (95% CI, -50 to -48 mg/100 g), a 12.0% decline; decreases began in 2005 and continued through 2014. Moreover, the sodium content of households' purchases decreased significantly for all top food sources of sodium between 2000 and 2014, including declines of more than 100 mg/100 g for condiments, sauces, and dips (-114 mg/100 g; 95% CI, -117 to -111 mg/100 g) and salty snacks (-142 mg/100 g; 95% CI, -144 to -141 mg/100 g). However, in all years, less than 2% of US households had packaged food and beverage purchases with sodium density of 1.1 mg/kcal or less.

Conclusions and relevance: In this nationwide study, significant reductions in sodium from packaged food purchases were achieved in the past 15 years. Nonetheless, most US households had food and beverage purchases with excessive sodium density. Findings suggest that more concerted sodium reduction efforts are needed in the United States.

Figure 1.. Sodium From US Households’ Packaged Food and Beverage Purchases and Trends in Total Purchases, 2000 to 2014

Values are the adjusted mean sodium (mg/d) (A) or weight (g/d) (B) per capita from households’ packaged food and beverage purchases from retail food stores in a given year, determined from multivariable, longitudinal linear regression models regressing purchases on indicator variables for year; values for table salt were determined from a 2-part model, including (1) a longitudinal probit model of the probability of purchasing and (2) a longitudinal log-linear regression of the amount purchased among purchasers. P values for time trends were derived from multivariable regression models treating year as a continuous variable, including linear, quadratic, and cubic terms as appropriate. All models were adjusted for household size and composition, race/ethnicity, income, educational level, and geographic market, and means were predicted at the distribution of race/ethnicity by income from US Census Bureau data. Data are from the Nielsen Homescan Consumer Panel, including 172 042 US households (754 608 year-level observations). ^aSignificantly different from 2000 (P < .001 by Wald postestimation test).

Figure 2.. Sodium Content of Packaged Foods and Beverages Purchased by US Households, 2000 to 2014

Values are the adjusted mean sodium content of households’ packaged food and beverage purchases from retail food stores in a given year, determined from multivariable, longitudinal linear regression models regressing purchases on indicator variables for year. P values for time trends were derived from multivariable regression models treating year as a continuous variable, including linear, quadratic, and cubic terms as appropriate. All models were adjusted for household size and composition, race/ethnicity, income, educational level, and geographic market, and means were predicted at the distribution of race/ethnicity by income from US Census Bureau data. Data are from the Nielsen Homescan Consumer Panel, including 172 042 US households (754 608 year-level observations). ^aSignificantly different from 2000 (P < .001 by Wald postestimation test).

Figure 3.. Sodium Density of Packaged Foods and Beverages Purchased by US Households, 2000 to 2014

Data are from the Nielsen Homescan Consumer Panel, including 172 042 US households (754 608 year-level observations). P values for time trends were derived from multivariable, regression models treating year as a continuous variable, including linear, quadratic, and cubic terms as appropriate. All models were adjusted for household size and composition, race/ethnicity, income, educational level, and geographic market, and values were predicted at the distribution of race/ethnicity by income from US Census Bureau data. ^aValues are adjusted 25th, 50th (median), and 75th percentile sodium density of households’ packaged food and beverage purchases from retail food stores in a given year, determined from multivariable quantile regression models regressing purchases on indicator variables for year with clustering on the household. ^bValues are the adjusted percentage of households that have total packaged food and beverage purchases with sodium density of 1.1 mg/kcal or less in a given year, determined from multivariable longitudinal logistic regression models regressing the binary outcome of having purchases with sodium density of 1.1 mg/kcal or less on indicator variables for year. ^cSignificantly different from 2000 (P < .001 by Wald postestimation test).