PRINCETON, N.J. — An effort launched in 2009 aimed at reducing obesity rates in the United States has far exceeded expectations thanks to steps taken by 16 food and beverage companies that pledged to make modest but meaningful progress toward reducing the number of calories in the marketplace.

As initially planned, the effort by 2012 was supposed to cut only about 12% of the excess calories needed to return obesity rates to what researcher called pre-epidemic levels. Instead, a study of the progress made to date suggests more than 60% of the excess calories have been removed from the food supply.

An independent, interim review of the calories cutting initiative of the Healthy Weight Commitment Foundation (H.W.C.F.) was published Sept. 17 in the American Journal of Preventive Medicine and was written by a group of researchers including Shu Wen Ng, Meghan M. Slining and Barry M. Popkin, all of the Department of Nutrition at the University of North Carolina at Chapel Hill.

In their original pledge, the 16 companies collectively pledged to remove 1 trillion calories from the marketplace by 2012 and 1.5 trillion by 2015. The evaluation, which was funded by the Robert Wood Johnson Foundation (R.W.J.F.), found the companies sold 6.4 trillion fewer calories in the United States in 2012 than in 2007, exceeding their 2012 goal by 540% and already exceeding their 2015 goal by 427%.

“Having 16 companies make individual changes that collectively cut 6.4 trillion calories is beyond impressive,” said James S. Marks, a senior vice-president at the R.W.J.F. “Imagine the impact if other industry leaders stepped up to make similar — or bigger — commitments to make and market lower-calorie, healthier products for families.”

The researchers tracked the companies’ progress by linking Nielsen Scantrack and Homescan data with the Nutrition Facts Panel on product packages.

“This linkage across tens of thousands of products allowed researchers to track consumer trends more thoroughly than ever before, demonstrating (for the first time) that the cumulative impact of these trends can be credibly tracked and measured,” according to an accompanying editorial looking at the research of Dr. Ng and his colleagues.

“Completing this evaluation is itself an impressive achievement,” the editorial said.

Aggregating the data, the researchers found American families with children bought 101 fewer calories per capita each day from packaged foods in 2012 than in 2007. Of the 101 calories, 78 were attributed to companies participating in the H.W.R.F. pledge.

The largest calorie cuts came from sweets and snacks (-21 calories); grain products such as ready-to-eat cereal and granolas (-17 calories); fats, oils, sauces and condiments (-15); and beverages (-14).

Offering perspective on the 101-calorie reduction, the editorial cited data suggesting an average of 161 calories per day would need to be reduced from the intake of children aged 2-19 years old to reduce current childhood obesity rates to pre-epidemic levels.

“The daily caloric reduction documented from H.W.C.F. companies is significant, but not sufficient to reverse the youth obesity epidemic,” the authors said.

They said the findings mirror positive trends indicated in recent years regarding obesity trends, particularly reports regarding young children.

“However, such early victories are fragile and must be bolstered and expanded to ensure continued progress,” they said. “Moreover, there is considerable evidence that obesity prevention initiatives are failing to reach communities of color and low-income communities equitably and thereby risk exacerbating existing obesity and health disparities.”

The writers urged other food companies not part of the pledge “to join the movement and launch similar initiatives to increase their low-calorie offerings and strongly promote healthier offerings.”

Dr. Marks of the Robert Wood Johnson Foundation echoed those comments and urged participating companies to “do even more to ensure that healthier choices are the easy and affordable choices for families.”

Addressing questions of how the calorie cuts would affect the businesses of participating companies, the researchers cited data indicating that between 2007 and 2001, better-for-you and lower-calories foods and beverage were leading drivers of successful financial performance for companies.