Front-of-package food labels: A narrative review

Front-of-package (FOP) labels may help shoppers make healthier food choices. The objectives of this review are, first, to establish the effectiveness of different FOP labels at enabling shoppers to identify which foods are healthy and which are not healthy, and, second, to assess whether different FOP labels induce shoppers to buy healthier foods. Some labels are nutrient-specific, such as Multiple Traffic Lights (MTL) and Guideline Daily Amounts (GDA). These labels state the content per serving of energy and of several substances, most commonly saturated fat, sugar, and sodium (or salt). Warning labels are another type of nutrient-specific FOP label (e.g., for food high in added sugar). Summary labels, such as Nutri-Score and labels with stars, translate the components of the food into a single value that indicates how healthy it is. Studies on FOP labels lack consistency. The majority of such studies indicate that they help shoppers to distinguish between healthy and less healthy foods. The designs that appear to be most successful in this regard are MTL, warning labels, and Nutri-Score. Labels based on GDA or that included stars were much less successful. Many studies using a simulated shopping situation reported that shoppers exposed to FOP labels had an increased intent to purchase healthier foods. Warning labels were the most consistently successful FOP design followed by MTL, Nutri-Score, and labels that included stars, while GDA failed in almost every study. Very few studies have been carried out in real-world supermarkets; the findings indicate that FOP labels or shelf labels may achieve a small degree of success (<2.0%) at persuading shoppers to buy healthier foods. Those advocating for effective FOP labels must resist opposition from food corporations.