Comparing the nutritional value of an apple with that of an orange is like comparing, well, apples and oranges. It gets more complicated when choosing between a russet potato and barbecue potato chips.
To help consumers with such comparisons, a growing number of supermarkets are now giving shoppers a simple tool—a rating system—that's separate from the existing nutritional label and any packaging claims. "For 30 years we've been telling consumers what foods to avoid," says Robert Murray, director of the Center for Healthy Weight and Nutrition at Nationwide Children's Hospital in Columbus, Ohio, and cofounder of a rating system used in school vending machines. "Now it's time to start telling them what foods to look for and help guide them through the store to make smart choices."
One of the first such rating systems, called Guiding Stars, was launched by Maine-based Hannaford Bros. in its 164 supermarkets throughout New England and New York. Meat, dairy, fresh produce, and packaged goods receive either a one-, two-, or three-star rating—corresponding to a good, better, or best nutritional score. Developed by a team of nutrition scientists and public-health experts, the formula credits a product for the presence of vitamins, minerals, dietary fiber, and whole grains and debits for added sugar, saturated and trans fats, cholesterol, and sodium.
More than 70 percent of Hannaford's products that have been considered, however, received no stars at all. Some critics claim that this ignores too many of a store's offerings and makes it difficult for shoppers to tell which foods may have just missed the cutoff for a star and which were toward the bottom of the nutrition spectrum. Hannaford's response: "Highlighting the foods with the most nutrition per calorie and not rating the 'best of the worst' was what our customers wanted," says Julie Greene, the company's director of healthy living.
Since its debut in 2006, Guiding Stars has had a marked impact on consumers' buying patterns, according to Greene. Sales of products with stars are outpacing those without—in some cases by wide margins. Starred packaged foods like pasta and canned soups sold at 2½ times the rate of unstarred items while sales of breakfast cereals with stars were more than three times higher than those without. Want milk with that? Try the three-star skim, which beat out no-star whole. Hannaford's parent company, Belgian-based Delhaize Group, is now expanding Guiding Stars to its subsidiary grocery chains Sweetbay and Food Lion.
While the three-tiered system is relatively simple and straightforward, says David Katz, the director of the Yale-Griffin Prevention Research Center, it lacks a level of differentiation among similar foods. It can't help consumers choose, for example, among several two-star yogurts.
Katz and a team of physicians and nutrition scientists, including the president of the American Cancer Society and the inventor of one of the first food-rating systems, the glycemic index, have developed their own program, the Overall Nutritional Quality Index. The ONQI, like Hannaford's system, considers a product's healthful content—vitamins, minerals, antioxidants, and omega fatty acids—as well as its unhealthful qualities like sodium, sugar, saturated fat, and cholesterol. The difference lies in ONQI's 100-point scale, which better highlights small differences between foods than Guiding Stars, according to Katz. "The formula also measures the biological quality of amino acids, the glycemic load, and energy density to calculate how the concentrations of particular nutrients in a food compare to the recommended concentrations in a healthy diet," he adds. They plan to launch ONQI in supermarkets across the country by fall of this year and to offer an interactive online guide.
Some experts are worried, though, that rating systems like ONQI may cause shoppers to neglect portion control and to choose too many foods of the same type. "I'm concerned that people may eat the ice cream with the highest-rated number, or the highest-rated muffin or candy and skip out on fruits, vegetables, dairy, and meat," says Brian Wansink, executive director of the USDA's Center for Nutrition Policy and Promotion and a professor of consumer behavior at Cornell.