Sara Lee, maker of Ball Park Franks, told "GMA" it strives "to provide our loyal consumers with multiple product options."
Ocean Spray said, "NuVal ... does not take into account product qualities beyond those listed on the label."
General Mills said, "Criteria for NuVal are not available to the public, making any actual comparisons impossible."
Click HERE to see full statements from the manufacturers.
All the manufacturers were skeptical that the nuances of food can be boiled down to a couple of digits. But Dr. Katz of Yale argued that's exactly what doctors have done for years at their patients' annual physicals.
"If expert training and medicine enables me and my colleagues to sum up the health of a person, we can certainly sum up the healthfulness of a loaf of bread," he said.
Safeway offers a Food Flex program in which the supermarket will use your club card records to analyze the foods you've purchased for the past three months and tell you how they compare to national nutritional recommendations.
I tried it and learned my family could stand to eat more protein and fiber and less sodium. Oops!
The program also suggests healthful alternatives for shoppers.
For example, I could switch from Safeway's regular turkey breast cold cuts, which have 860 milligrams of sodium, to Safeway's Eating Right turkey breast, which has 526 milligrams.
Instead of Lucerne fat-free vanilla light yogurt with just 5 milligrams of protein, I could buy Lucerne fat-free plain yogurt, which has twice as much protein.
And if I trade in my butter lettuce for romaine, I would get 4 grams of fiber per serving instead of just one.
Painless tweaks for better nutrition.