WASHINGTON — The Obama administration on Thursday will propose the first major revamp of nutrition labels in more than two decades, an update that would emphasize calorie information, include the amount of added sugars and revise serving sizes to reflect how people really consume food.

The revision is aimed, in part, at addressing serious public health issues, including obesity and other chronic diseases. Administration officials believe the new labels could lead consumers to make more healthful food choices and encourage the food industry to reformulate some products, particularly those with high amounts of added sugar.

First Lady Michelle Obama, who has made better nutrition a focus of her "Let's Move!" initiative to battle childhood obesity, is slated to announce the Food and Drug Administration proposal at the White House with top administration officials.

"Our guiding principle here is very simple: that you as a parent and a consumer should be able to walk into your local grocery store, pick up an item off the shelf, and be able to tell whether it's good for your family," she said in a statement.

Thursday's announcement will begin a 90-day period for public comments on the proposal. The administration plans to release a final rule within the next year, although there is no deadline.

Given the costs tied to revising the labels, found on about 700,000 products, the FDA is proposing an implementation period of two years after the rule is issued, an administration official said.

The Grocery Manufacturers Assn., which represents more than 300 companies, said "the time is right for an update," called the proposal "a thoughtful review" and promised to work with the FDA. But the organization also said: "It is critical that any changes are based on the most current and reliable science. Equally as important is ensuring that any changes ultimately serve to inform, and not confuse, consumers."

On the proposed label, the calorie count would appear in larger, bold typeface. The updated label would also include a separate entry in the sugar section to differentiate between added sugar and natural sugar.

Administration officials said that would help consumers comply with dietary guidelines recommending Americans decrease added sugar intake. But Marion Nestle, a professor of nutrition at New York University, predicted that the move could prompt push-back from food companies, which have a powerful Washington lobbying operation.

"The food industry is really eager for people to not know how much sugar there is," she said.

Still, some public health advocates said that the added sugar category doesn't go far enough. The FDA should also display the amount of sugar as a percentage of recommended daily value, argued Michael F. Jacobson, the executive director of the Center for Science in the Public Interest. "So many people consume far too much," he said.

Jacobson noted that the American Heart Assn. recommends women consume no more than 25 grams of added sugar per day and men no more than 35 grams per day, while one can of soda contains about 40 grams.

To ensure compliance with the proposed requirement, companies would have to keep records of added sugar for FDA inspection.

The FDA proposal would also revise serving sizes to reflect the most recent data on consumer habits. The serving size for soda is currently 8 ounces, but consumers often drink soda in 12-ounce cans or even larger bottles.

The current rules allow manufacturers to use a larger serving size, as some soda makers do, but the proposed rule would require the serving size to be at least 12 ounces.

With the update, the serving sizes set in 1994 would increase for some products, such as ice cream, while sizes for other products, such as yogurt, would decrease.

"The serving sizes for many foods are a joke now — the half-cup of ice cream, 2-ounce muffins and bagels, which haven't been seen in decades," said Jacobson, praising proposed revisions.

For certain items that are typically finished all at once, such as a 20-ounce soda bottle, the updated label will also require manufacturers to display nutrition information for the entire package.

If a food package is two times the serving size and could be consumed all at once, such as a 24-ounce soda bottle, the FDA would require a dual-column label with a breakdown by both serving size and container size.

The administration officials, who discussed the proposal on the condition that they not be identified, said an economic analysis indicated the new label could bring between $20 billion and $30 billion in benefits at a cost of about $2 billion over 20 years, but did not provide details of the study.

The food industry, which would be responsible for updating the labels on its products, would bear much of the cost.

Citing obesity as one of the primary reasons for the update, the administration officials acknowledged that the label alone will not solve the epidemic but said it could help curb it.

Obesity rates have remained steady for most Americans, although a study released this week by the Centers for Disease Control and Prevention showed a 43% drop over the past decade for 2- to 5-year-old children.

The updated nutrition label would also highlight different supplements than the current one. Food producers would no longer be mandated to include Vitamins A and C on the label. Instead, they would be required to display values for potassium and Vitamin D, more of which the FDA recommends the U.S. population consume.

daniel.rothberg@latimes.com