LOS ANGELES » Uncle Sam wants you to know more about what you’re eating.

The Food and Drug Administration wants to revise the nutrition facts label — that breakdown of fats, salts, sugars and nutrients on packaging — to give consumers more useful information and help fight the national obesity epidemic.

A proposal is in the works to change several parts of the label, including more accurate serving sizes, a greater emphasis on calories and a diminished role in the daily percent values for substances like fat, sodium and carbohydrates.

It’s the latest attempt to improve the way Americans view food and make choices about what they eat, and comes in the wake of major advances in nutrition regulations by the Obama administration.

Calorie counts are popping up on menus of chain restaurants across the country and the longstanding food pyramid was toppled this year by the U.S. government in favor of a plate that gives a picture of what a healthy daily diet looks like.

The struggle to redesign the labels on every box, can and carton has been in the works since 2003, and some of the changes could be proposed as soon as this year. FDA Deputy Commissioner Michael Taylor cautions not to expect a grand overhaul, but the revamped label does mark a shift to create a more useful nutritional snapshot of foods millions of Americans consume every day.

"There’s no question obesity is a central public health concern that the nutrition facts panel can play a role in. It’s obviously not a magic wand but it can be an informative tool," said Taylor.

For two decades, the black and white label has offered a glance of nutritional information about what’s inside each package, including calories and grams of fats, cholesterol, protein and carbohydrates. Critics have complained it’s confusing and doesn’t offer a simpler way to make a choice about whether it’s good for them — a judgment the industry wants to leave to consumers.

The proposed label is likely to produce several changes, said Taylor.

For starters, portion sizes should better reflect reality. The 2.5 servings listed on a 20-ounce soda bottle are typically slurped up by an individual in one sitting rather than split between a couple and their child. The same goes for a can of soup, where one serving is often listed as two-fifths of a can.

The FDA is also likely to find a way to emphasize calories, which many people rely on for weight control. Other items likely to disappear or change because they haven’t proven useful include calories from fat and the daily percent value numbers that show how much what an average diet should include.

Still, some wish the revisions would go further to list information about the amount of preservatives in a food and the degree of processing it has undergone. Health activists say such changes could help trim waistlines in America.

The food industry wouldn’t like to see many major changes. The current label is easily recognizable and adaptable to food packages of different sizes because it’s simple, said Regina Hildwine, director for science, policy, labeling and standards at the Grocery Manufacturers Association.

Hildwine says her Washington-based group, which represents 300 top food, beverage companies — including Nestle, General Mills Inc., and Coca-Cola Co. — has provided extensive feedback to the FDA in the run-up to their proposed rule.

"I personally talk with FDA on a regular basis to share views and get information and sometimes they call me," said Hildwine.

Advocates believe that the government and industry are too cozy, and that food companies are reluctant to overhaul food labels for fear of their profits being hurt.

"It’s against the industry’s interest to help the consumer make better choices because then they’ll sell less food," said Kelly Brownell, director of Yale University’s Rudd Center for Food Policy and Obesity. "If the population is going to lose weight, it’s going to eat less food, so that means less business for them."

There’s no shortage of ideas on how to improve the label. A recent contest by the University of California, Berkeley and Good Magazine yielded 60 colorful new designs.

A familiar theme popped up: red, yellow and green colors of a traffic light to indicate whether a food is good or bad. Another offered thumbs up and thumbs down on nutrients, depending on how much.

Manufacturers don’t think a stoplight system would work because most foods have a mix of nutrients and diets are not the same for everyone, Hildwine said.

"A color-coded scheme would not be as helpful to consumers as a fact-based approach," she said.

The winning design was created by Renee Walker, whose label is topped by a large blocks of color above the nutrient listing, with each block representing an ingredient. For example, a jar of peanut butter would typically have a big box for peanuts, a smaller box for sugar, and other blocks for other ingredients.

The FDA has long avoided putting qualitative judgments about food on labels in favor of a simple listing of macronutrients, said contest judge and Center for Science in the Public Interest executive director Michael Jacobson.

Before the FDA first introduced the nutrition facts label in 1992, choosy Americans puzzled over a tiny printed listing of ingredients on packages to help determine what to feed their families.

As a result, Americans often relied on gut feelings to choose their diets at a time when the obesity epidemic was taking root.

Dr. David Kessler served as FDA commissioner during what he called a "battle royale" over the first label.

"Every change is a battle with the food industry," said Kessler. "The food label that we implemented — did it harm the food industry in any way? No. In fact, I’m sure they profited from it."

Kessler, now a University of California, San Francisco professor and author, says the label is due for an update.

Like many experts, he’d like to see the new label address how much ingredients are processed.

A pie-chart could, for example, show how much of a jar of tomato sauce is from actual tomatoes, and how much is sugar, fats, sodium, water and whatever else may be in it.

Not that all food processing is bad. Skim milk and lean meat have been skimmed and trimmed of fat. Frozen vegetables are typically captured at peak ripeness without introduction of preservatives or sodium.

But many highly processed foods are stuffed with unpronounceable and nutritionally questionable substances. Add fat, sugar and salt, as processed foods so often do, Kessler said, and you have the perfect recipe for an American-style obesity epidemic.