The researchers compared four different labeling systems and found that the Nutrition Facts label currently required on most food products in the US and Canada was least useable. That label, which lists the percent daily value of several nutrients, took more time to understand and led to nutrition choices hardly different from chance. Another label type, NuVal, enabled quick and nutritious choices. NuVal is a shelf sticker used in some American food markets, which indicates the overall nutritional value of each food item with a number from 1-100.
Resolving “nutrition conflicts”
“Food shoppers typically have a limited amount of time to make each food choice, and they find the Nutrition Facts labels to be confusing and difficult to use,” says Peter Helfer, lead author and PhD student in Psychology and Neuroscience at McGill. “One product may be low in fat, but high in sugar, while another product may be just the opposite. Nutrition Facts labels can highlight nutrition conflicts but fail to resolve them. Even educated and motivated shoppers have difficulty picking out the most nutritious product with these labels.”
NuVal scores are calculated by nutrition experts at several universities, including Yale, Harvard, and Northwestern, and emphasize both the positive and negative aspects of each food. By reducing nutritional content to a single number, NuVal labels resolve nutrition conflicts.
Two other labeling methods produced mixed results. The Traffic Light system used in the UK allowed for a bit more nutritious choices than chance. But it took more time to use, because the colors of several traffic lights have to be counted and compared. Labels that certify some foods as nutritious, but not others, are used in Denmark, Sweden, and Canada. These allowed quick decisions, but did not increase nutritious choices. “Such certification labels are not sufficiently discriminating to produce consistently better nutrition. They also create controversies about exactly where to draw the line between nutritious and harmful foods,” says co-author Thomas Shultz, Professor of Psychology and Computer Science at McGill.
The widespread availability of low-nutrition, high-calorie food is believed to be an important cause of an epidemic of obesity and associated diseases throughout the world. Shultz argues that “Empowering consumers to make healthier food choices with valid and useful nutrition labeling could help to stem this epidemic. If consumers have the information to make nutritious choices, this could nudge food sellers and producers to improve their products.”
Picture: compared labelling systems (%Daily Value, Traffic Light, NuVal, and Heart)
The effects of nutrition labeling on consumer food choice: a psychological experiment and computational model
Peter Helfer, Thomas R. Shultz
Annals of the New York Academy of Sciences, Dec. 2014