A one to 100-point food rating system would help consumers choose what goes into their carts, says a new study.
However, a nutrition index alone is not enough to change the buying and eating habits of U.S. consumers, said a health behavior expert who was not part of the study.
About 800 adults participated in online marketing research and two-hour focus groups about the NuVal Nutritional Scoring System. The system, based on the Overall Nutritional Quality Index (ONQI), uses an algorithm to score foods based on the nutrients they contain, and is described in the November/December issue of the American Journal of Health Promotion
"In developing the system, we included nutrients of known scientific importance," including vitamins, minerals, omega-3 fatty acids, fat, sugar, sodium, cholesterol and antioxidants, said David Katz, M.D., leader of the ONQI development team and the study''s lead author.
Katz is director of the Prevention Research Center at Yale University-Griffin Hospital in Connecticut.
The system also examines the documented health effects for each nutrient. For example, antioxidants are associated strongly with disease prevention, so foods containing them get a scoring reward, whereas foods containing trans fat receive a penalty because of this fat''s association with heart disease. Fiber- and antioxidant-packed spinach merits a score of 100, whereas sugar-laden soda receives a one.
"All too often patients stumble over the hype on the front of food packaging. They also have difficulty taking the factual details on the back - in the nutrition facts panel and ingredient list - and applying it to making healthy food choices. Most people simply lack the nutritional expertise to do this," Katz said.
Ninety-three percent of consumers agreed that the food scoring system would influence their purchasing decisions at the grocery store. Two-thirds said they would be more likely to shop at a store that had the scoring system compared to one that did not, the researchers found.
Researchers also compared ONQI scores for seven days of the DASH diet, designed to lower blood pressure, to a typical American diet. The more nutritious DASH diet consistently logged a higher score, which indicates that choosing foods with higher NuVal scores will help consumers eat a healthier diet overall, the researchers say.
"The value of the index is more for the scientific audience rather than the consumer at this point," said Dawn Wilson, Ph.D., a professor and health behavior researcher at the University of South Carolina. She said that although the authors conducted an extensive review of the literature, had an expert panel and tested the index against other established indices, they did not examine how well the index predicts changes in health outcomes over time.
"A simple nutritional index is not going to keep consumers from buying or eating the foods they like. Dietary behavior changes require a much more sophisticated approach than simply trying to educate consumers about the nutritional quality of foods," Wilson said.