A study published in American Journal of Clinical Nutrition evaluated if the presence of a shelf nutrition label had an effect on grocery purchases.
Food labels enable consumers to make informed food choices using the information on the sides of the package, including ingredients, allergens, and nutrition facts. Nutrition facts are especially important to help consumers make healthy food choices at the point of purchase. However, despite the presence of nutrition labels on food products worldwide, obesity and associated chronic illness are still prevalent in many countries, and the consumption of “unhealthy” food may be a potential culprit.
In 2011, after a review of the theory and evidence associated with food labels, the Institute of Medicine’s Committee on Examination of Front-of-Package Nutrition Rating Systems and Symbols recommended a development of food labels on the front of packages or on the shelf tags that would provide a clear ranking of the healthfulness of the product. Healthfulness refers to how wholesome a product is in contributing to an overall healthful condition.
NuVal Shelf Nutrition Labels
NuVal is a type of shelf nutrition label developed by Nuval, LLC. The labels score food on a scale of 1 (worst) to 100 (best) on the basis of more than 30 micro-and macronutrient properties of food.
For the 1.0 version of NuVal, scores are highly correlated with the Healthy Eating Index in 2005, as well as a lower risk of chronic illness and all-cause mortality. This suggests that consumers could experience health improvements if they make changes to their diet consistent with consuming products with higher scores.
A previous study analyzing household purchasing data across NuVal and non-NuVal retailers found that consumers purchased more healthy products the retailer that utilized NuVal codes.
Nuval 2.0 reflects the latest dietary guidelines
In 2014, NuVal’s scoring algorithm changed to reflect the latest US Dietary guidelines and scientific evidence. Called NuVal 2.0, the updated algorithm improved differentiation between food products compared to its predecessor, NuVal 1.0. This update resulted in lowered NuVal scores for some products and raised scores for others.
Researchers evaluated the impact of the shift to NuVal 2.0 to on consumer purchases at one American supermarket chain before and after the update.
For the study, they focused on yogurt products because several yogurt scores showed large changes after the upgrade to NuVal 2.0. These results were coupled with market research survey data that identified the percentage of consumers who indicated that NuVal influenced their purchasing patterns. The results of their study are published in the American Journal of Clinical Nutrition.
Researchers obtained market research data from 665 adults in June 2016. These adults were members of an online panel who shopped at one of two US supermarket chains that employed the NuVal scoring system. The survey provided insights on the percentage of respondents who reported ever noticing NuVal scores and understood that these scores indicated the nutritional value of the product, and recognized that higher scores indicated healthier products. The survey also indicated what percentage of those respondents stated that NuVal scores had ever influenced the foods they bought.
NuVal scores have an impact on shopping behaviour
The results showed that 44% of the survey participants stated they had noticed NuVal scores posted in the stores; of these, 32% knew the scores related to nutritional value and healthiness of products and knew that a higher score was better. Fifteen percent of these individuals stated that NuVal scores often or sometimes influenced their food purchases, while 8% of respondents reported using NuVal scores to influence their milk, yogurt, and dairy purchases. Interestingly, the survey also found that 80.6% of the shoppers surveyed reported they often or sometimes relied on other nutrition information, other than NuVal to make their shopping choices.
Lower scores for yogurts led to fewer yogurt sales
Their analysis revealed that reduced scores indeed translated into reduced demand. Grocery stores sold an average of approximately 355 units of yogurt were sold per week during the NuVal 1.0 period, and this figure dropped to 302 units sold per week in the NuVal 2.0 period. While this likely indicates purchases being influenced by NuVal scores, the authors state that the decline could also be due to other unrelated factors.
The restriction of the analysis to one food category is one limitation of the study. While sales of lower ranked yogurts decreased, it is possible that there were increased sales of other less healthy products.
Other limitations include the inability to control for potential product price changes driven by changes in demand due to labelling, as well as the inability to control for changes in consumer demand for non-yogurt products arising from the shift to NuVal 2.0.
The survey was also limited to a convenience sample of members of an online panel of regular shoppers at one of two grocery chains that utilized NuVal scores. Additionally, the data was not matched between the two analyses; for example, the time frames were different and the store locations were different. The authors suggest that future studies should attempt to replicate these results using a more representative consumer population to validate the study findings.
Benefits of the scoring system
In sum, the findings from this study support the previous findings that front-of-package and shelf labelling using a scoring system like NuVal can improve consumer food purchasing patterns, and may lead to improved health outcomes.
Labels could also be customized to a consumer subset. For instance, consumers with high blood pressure could be provided with reweighted scores that specify which items have “healthier” sodium content, thereby enabling them to choose items that will not exacerbate their conditions. These labels may also be of benefit as part of consumers’ virtual shopping experience and may be easier to implement in the electronic environment.
Written by Sara Alvarado BSc, MPH
Reference: Finkelstein, E., Li, W., Melo, G., Strombotne, K., and Zhen, C. (2018). Identifying the effect of shelf nutritional labels on consumer purchases: results of a natural experiment and consumer survey. American Journal of Clinical Nutrition 107: 647-651.