Restaurant menus can make it difficult to tell how much added sugar is hiding in a drink, dessert or other menu item. New research suggests a clear warning at the moment someone places an order may influence the choice they make.
In an online randomized controlled trial, researchers tested added-sugar warning labels on restaurant menus with more than 10,000 adults across the United States. Participants who saw the most effective label selected meals containing more than 10 fewer grams of added sugar on average than those who ordered from menus without warning labels.
The study, published in The Lancet Public Health, looked at simulated orders from full-service and fast-food restaurant menus. It did not track real-world purchases, measure how much sugar participants ultimately consumed or examine whether warning labels improved health over time.
Still, the findings suggest that design matters when restaurants provide nutrition information. The most effective warning was a black triangle containing a spoon and exclamation point, paired with the words “SUGAR WARNING.” The label appeared directly next to menu items high in added sugar and was displayed at the same height as the menu text.
“This is a substantial amount, as the daily recommended limit for added sugars is 50 grams,” said Jennifer Falbe, a UC Davis professor and senior author of the study.
Researchers also tested a taller red icon-only label. Participants who saw that version selected meals containing almost 7 fewer grams of added sugar on average than participants who ordered from menus without warnings.
The findings build on earlier research suggesting that menu warnings may be more effective when people actually notice them. A previous online trial tested a smaller icon-only label and found more modest changes in simulated orders. Only 21% of participants recalled seeing the label.
The new study was designed to test labels that would be more difficult to overlook. Researchers compared the icon-plus-text label with the larger icon-only version and also examined two thresholds for deciding which menu items should carry a warning.
One threshold applied a label when a serving contained at least 50% of the U.S. Food and Drug Administration’s Daily Value for added sugar. The other applied the label at 100% of the Daily Value. Researchers did not find a meaningful difference between the thresholds on the limited number of menus tested.
The study arrives as California lawmakers consider Senate Bill 869, a proposal that would require certain chain restaurants to place an added-sugar warning icon next to beverages containing at least 50% of the FDA Daily Value per serving. The proposal would apply to chain restaurants with 20 or more locations and could cover items such as fountain drinks and blended beverages.
New York City already requires added-sugar warning labels for certain restaurant items containing at least 100% of the Daily Value.
Warning labels are not a complete solution for reducing added sugar intake. The online study asked participants to make hypothetical choices rather than spend their own money in real restaurants. Actual orders can be shaped by many other factors, including price, taste, hunger, habit and convenience.
The study also did not show whether diners would respond to warning labels in the same way after seeing them repeatedly over time. Some people may become accustomed to the icons or choose the same items despite the additional information.
But restaurant nutrition information is only useful when people can understand and notice it. The findings suggest that a visible, easy-to-interpret warning may help diners recognize high-sugar options and make a more informed decision before they order.
The study was funded by the American Diabetes Association and Bloomberg Philanthropies.