With one-third of U.S. adults obese and another third overweight, it's pretty clear that Americans need to change their diets and eat healthier foods. But how?
The federal government and public health officials have favored putting more information on food labels and on restaurant menus to help people make better choices. But listing calories, fat, sugar and other nutrients may still fall short in changing people's behaviors, according to one expert. Instead, she suggests, give foods a simple numerical score to indicate health value.
In a paper published in the Journal of the Academy of Nutrition and Dietetics, Dr. Joanne E. Arsenault and her colleagues propose a food rating system that gives consumer a score for almost every food product they purchase. A number could be posted on the front of a package or on a grocery-store bin to indicate the ranking.
Such a system would be quicker than studying the nutrition facts panel on a product and would bring some badly needed consistency to the marketplace, Arsenault, a nutrition policy analyst at Research Triangle Institute, told TakePart.
"I think most people believe consumers need or want something simpler in addition to all the information that's available on the nutrition facts panel—something they can quickly look at to assess the quality of a food," she said.
Manufacturers and other groups have made attempts to identify healthy foods. The Food and Drug Administration has a "heart healthy" label while the American Heart Assn. licenses a "heart check" symbol. Kraft has a "sensible solution" label and PepsiCo has a "Smart Spot" designation for some products. But there has been growing criticism that a single, unified food-rating system is needed.
"One of the problems with this whole field is there are a lot of systems out there," she says. "It can add to consumer confusion when there are several different systems. I think the government is trying to figure out how and if they should regulate this for companies."
Several nutrition research groups have attempted a rating system. However, the Research Triangle Institute system, which was funded by Department of Health and Human Services, is different in a key respect: Unlike other approaches to rate the health value of foods, this system doesn't weigh nutrients equally.
The system is based on data from 16,500 participants, taken from the 2005-2008 National Health and Nutrition Examination Survey, to predict an overall dietary quality score called the Healthy Eating Index. Using this statistical model, the researchers found that eight nutrients—seven nutrients and added sugars—were most important to explain the Healthy Eating Index score. The algorithm included positive weighting for protein, unsaturated fat, fiber, calcium and vitamin C and negative weighting for saturated fat, sodium and added sugars.
"How do you weigh the nutrients? Are they equally important or should some be weighted differently than others? That was probably the most difficult part," Arsenault says. "Hardly any of the other systems have tried to do that."
The researchers found that adding more nutrient information didn't change the score much. The model based on eight nutrients was similar to a model based on 16 nutrients. So, the authors concluded: "Inclusion of additional nutrients would be unlikely to improve the algorithm."
Fruits and vegetables score the highest and sweet snacks the lowest. For example, raw spinach scores 215.7 compared to sweetened soft drinks, which scored -24.8.
There are some surprises in the scoring system, such as the score for dill pickles, -240.9, which is based on its super-high sodium content. Italian dressing, reduced calorie, fat-free was scored -115.1.
"That came up low because it's high in sodium and it's not particularly high in nutrients, such as vitamins, that would drive up the score higher," Arsenault says.
An advantage to the RTI algorithm is that it can easily be used to rate the nutritional quality of overall diets as well as individual foods. But there is more work to do, Arsenault says. While shoppers could stand in a grocery store and compare the scores on cereal boxes to find a higher score, the system would be meaningless without using comparisons. The next step is to create a method to indicate which scores are in a healthy or unhealthy range.
"That is the hard part—putting a value on these numbers and deciding what is a good cutoff or how to break the numbers down into good, middle or bad," Arsenault says. "The actual number may not be that helpful in itself. We would have to do more research on that."
Question: Would you like to see food products rated on a numerical scale to indicate health quality? Tell us what you think in the comments.