Among the proposed changes in the more than 500 pages of regulations for the revised Nutrition Facts label are adjustments in the daily values, or reference daily intakes, of a range of nutrients such as sodium and calcium. The daily value for calcium, based on a 2,000- calorie diet, would go up from 1,000 milligrams to 1,300 milligrams, for example, and for potassium, from 3,500 milligrams to 4,700 milligrams. The reference intake for fiber would increase from 25 grams to 28 grams.

These changes could complicate matters for food manufacturers. While the Food and Drug Administration has estimated the food industry will spend about $2 billion on the label changes, some estimate that costs will be much higher, and go beyond the label itself.

“There’s going to be a huge investment to changing their whole marketing strategies,” said Jillian Wein Riley, an associate with the consulting firm Reed Smith and a former FDA attorney. “One cup of milk would have 23 percent of the daily value [for calcium], whereas it’s 30 percent now. From a marketing perspective, a fifth doesn’t sound nearly as good as a third.”

But whatever the costs associated with the changes, the FDA insists the benefits are worth it. The new information could cut obesity-related health care costs by up to $30 billion over the next two decades, the agency has said.

Some critics question those numbers. Bruce Silverglade, an attorney and food regulation specialist with OFW Law, worked to get the original labeling law passed in 1990. “We know that the changes are going to cost the food industry billions of dollars, that’s for sure,” Silverglade said shortly after the proposed changes emerged. “But the estimated benefits are more elusive and depend on a myriad of factors.”