CHAPEL HILL, N.C. — U.S. households significantly decreased the amount of sodium in their packaged food and beverage purchases by 396 mg per day from 2000 to 2014, according to a study that appeared on-line June 5 in JAMA Internal Medicine. Still, most U.S. households had food and beverage purchases with excessive sodium density in 2014.

The study may be found here.

Researchers from the University of North Carolina in Chapel Hill, N.C., for the study used the 2014 Nielsen Homescan Consumer Panel, a population-based sample of households that used bar code scanners to record all packaged foods purchased. They evaluated three measures: sodium per capita, or the amount of sodium purchased daily per person; sodium content, or the amount of sodium relative to the amount of food; and sodium density, or the amount of sodium relative to the energy (calories) in food.

Besides the drop of 396 mg per day in sodium per capita, the sodium content of households’ packaged foods purchases decreased significantly by 49 mg.  The sodium content of packaged foods purchased declined by 12% overall and by at least 10% for 7 of the top 10 food group sources of sodium. The sodium content decreased significantly for all food sources of sodium, including more than 100 mg per 100 grams for both condiments, sauces and dips, and salty snacks. The sodium density decreased significantly by 84 mg per 1,000 calories.

Despite the significant declines, most U.S. households still had packaged food and beverage purchases with sodium density exceeding 1.1 mg per calorie.

“Our findings support the need for more concerted nationwide efforts to accelerate the pace of sodium reduction, and the U.S. Food and Drug Administration’s recently proposed phased targets for the sodium content of industrially processed foods will likely have a critical role,” the study’s authors said.

The F.D.A. in the June 2, 2016, issue of the Federal Register published a draft guidance called “Voluntary Sodium Reduction Goals: Target Mean and Upper Bound Concentrations for Sodium in Commercially Processed, Packaged, and Prepared Foods.” The F.D.A. guidance said about 75% of sodium consumed by Americans is added to food products before they are sold. The F.D.A. guidance may be found here.

The study in JAMA Internal Medicine included 172,042 households and about 1.5 million products. Support for the study came from the Robert Wood Johnson Foundation, the National Institutes of Health, and the Carolina Population Center and its National Institutes of Health Center grant at the University of North Carolina.

The study’s authors said they recognized the study does not report whether all purchased foods are consumed, but results of waste collection studies suggest consumer-level food loss has not changed in the past 15 years.

“Therefore, trends in sodium purchased may be an adequate reflection of trends in sodium intake,” the study’s authors said.

The study’s authors also said additional studies need to examine whether decreases in sodium from packaged foods were offset by increases in sodium from away-from-home purchases.