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A GPS for Better Nutrition? Looking Under the Hood at Hy-Vee’s NuVal System - Page 2 PDF Print E-mail
News/Features - Health
Written by Jeff Ignatius   
Thursday, 21 July 2011 05:51

The NuVal Algorithm

While NuVal is a proprietary rating system, its Web site (at NuVal.com/science) offers a basic breakdown of what’s measured and how it affects the score.

The system includes a calculation for “numerator nutrients,” which are “considered to have generally favorable effects on health.” These include fiber, folate, Vitamin A, Vitamin C, Vitamin D, Vitamin E, Vitamin B12, Vitamin B6, potassium, calcium, zinc, Omega-3 fatty acids, total bioflavonoids, total carotenoids, magnesium, and iron.

That number is then divided by the calculation for “denominator nutrients,” considered to have “generally unfavorable effects on health”: saturated fat, trans fat, sodium, sugar, and cholesterol.

Other factors considered in determining the final 1-to-100 score are protein quality, fat quality, glycemic load, and energy density.

The algorithm was built on and tested against “face validity,” which Katz explained by way of a few questions: “What are the foods the most expert people think are most nutritious? What are the foods the most expert people think are less nutritious? You start there, and you build around that.”

He admitted that face validity is “not a very high standard. But frankly we don’t have a gold standard for measuring nutritional quality of an individual food. In some ways it’s perfectly obvious; everybody agrees that spinach is a really nutritious food, and everybody agrees that marshmallows are not. But based on what? ... You really have to beat up on that to get people to figure out what’s going on.”

Since the algorithm was finalized, 90,000 foods have been scored – including more than 20,000 carried by Hy-Vee. This is done through the method of “imputation” – which involves analyzing data about the food rather than the physical food itself. “If you have the ingredients, and you have nutrition facts, there’s only basically a very narrow, fixed way those ingredients can come together to produce those nutrition facts,” Katz explained. “So you can reverse-engineer the rest ... .” Through that process, he added, one could generate as many as 150 nutrient entries for a food, but NuVal uses approximately 30.

It’s also worth noting that the factors that determine a food’s NuVal score are not all available on the nutrition panel – such as the biological quality of protein.

And there are labeling practices and regulations (and loopholes) that NuVal is designed to get around. Omega-3 fatty acids – considered good for your health – are not universally declared by manufacturers, for instance, but NuVal calculates them. On the negative side, there are rounding rules through which manufacturers claim foods have no trans fat because they’ve made the serving size small enough that trans fat is less than half a gram; NuVal includes that trans fat in its calculations.

“We have to go beyond the nutrition-fact panel ... ,” Katz said.

We’re Not Telling You What to Eat”

NuVal isn’t the only nutrition-rating system.

The Guiding Stars system (GuidingStars.com) is more widely used – in place at more than 1,600 grocery stores – and is more reductive, giving foods zero, one, two, or three stars based on nutritional content.

Jewel (with three stores on the Illinois side of the river) uses the Nutrition iQ system (JewelOsco.com/nutritioniq), which is less reductive and uses colored labels to denote foods that have, for example, good fiber, good protein, low sodium, vitamins, minerals, or 100-percent juice.

And stores generally are focusing more on nutrition. Walmart earlier this year unveiled a new nutrition initiative – including reformulating products and “developing strong criteria for a simple front-of-package seal that will help consumers instantly identify truly healthier food options such as whole-grain cereal, whole-wheat pasta, or unsweetened canned fruit,” according to a press release.

But because Hy-Vee dominates the Quad Cities market – and because no other local grocer outside of Jewel has a nutrition-rating system – NuVal is the focus here. (I visited Aldi, Fareway, Save-a-Lot, Schnucks, Target, and Walmart.)

The nature of NuVal makes it ideal for side-to-side comparisons of similar foods. Katz said NuVal allows consumers to make informed decisions about not just nutrition but also value. While many people think “better” foods cost significantly more, that’s typically not the case. “There’s the opportunity to trade up nutritionally” without paying much (if any) more, Katz said.

A longer-term goal, he said, is to get people to compare products across categories and not just within them. “NuVal is universal,” Katz said. “It’s the same scoring system from soup to nuts. So it also is pointing out: You probably should spend a little more time in the produce aisle, and you should maybe spend a little less time in the cookie aisle. ... We do hope that it will not only empower people to make better choices within a given aisle, but over time will also nudge them to spend more time in aisles that have the most nutritious choices.”

If the gentleness of that statement isn’t clear enough, part of the marketing genius of NuVal is that it doesn’t impose itself. The shelf tags themselves are unobtrusive and easy to ignore when you’re buying Chips Ahoy! (a 6, by the way), and Katz was careful to say that there’s no number below which one shouldn’t buy. (Anything below 10, he said, should be a “rare and occasional thing.”)

He stressed that “people who use a GPS system don’t want to be told where to go. They just want to be told how to get there. NuVal was really designed with that concept in mind. We’re not the boss of you, and we’re not telling you what to eat.”

The aim, he said, is to choose a more nutritious food whenever possible – even if you’re still buying candy and cookies: “In every category and whatever the range, you have the opportunity to trade up, even when you’re indulging yourself.”

This was echoed by Hy-Vee’s Comer, who said the store doesn’t want to prevent people from buying low-scoring foods. “We wanted to give our customers an easy way to evaluate products and make healthier choices,” she said. “We think it’s working.”

Dietitian Macon gave some examples of how she uses NuVal: “I ... create cut-off points when I am shopping with my kids. It takes the pressure off of Mom; I’m not the bad guy for saying ‘no’ to a low-scoring food. My kids know that scores below a certain number are treats in our house, not everyday foods.

“NuVal makes it easier to see the value in making healthy choices for my family, even if those choices have a higher price tag. The food we eat is probably the biggest investment we make in our health most days. I divide the price by the NuVal score as I shop and realize that even if the price is higher, often I pay less for each nutrient in that food than I would if I chose a lower-scoring, lower-priced product.”