Association between salt substitutes/enhancers and changes in sodium levels in fast-food restaurants: a cross-sectional analysis.

BACKGROUND: Restaurant foods have high sodium levels, and efforts have been made to promote reductions. The objective of this study was to understand if salt substitutes and enhancers are associated with changes in sodium levels in fast-food restaurants.

METHODS: A longitudinal database (MENU-FLIP) containing nutrition information for Canadian chain restaurants with 20 or more locations nationally was created in 2010 and updated in 2013 and 2016. In 2016, when available, ingredient lists were collected from restaurant websites and searched for the presence of salt substitutes/enhancers. Changes in sodium levels (per serving) and the prevalence of salt substitutes/enhancers in 222 foods from 12 of the leading fast-food restaurant chains were compared across 3 time points.

RESULTS: Sixty-nine percent of foods contained a salt substitute/enhancer. Substitutes/enhancers were found in every restaurant chain ( n = 12) for which ingredient data were available. The most common substitutes/enhancers were yeast extracts (in 30% of foods), calcium chloride (28%), monosodium glutamate (14%) and potassium chloride (12%). Sodium levels in foods that contained substitutes/enhancers decreased significantly more (190 ± 42 mg/serving) over the study period than those in foods that did not contain a substitute/enhancer (40 ± 17 mg/serving, p < 0.001).

INTERPRETATION: Salt substitutes and enhancers are prevalent in restaurant foods and are one means by which restaurants may be lowering sodium levels in their foods. At this time, the potential consequences of these findings, if any, are uncertain.