Food sales data show families are cutting back on calories

American families with kids bought 101f ewer calories per person per day in packaged foods in 2012 than they did in 2007, according to an analysis of a pledge by big food companies to reduce calories in the marketplace. It’s an “impressive” accomplishment but not sufficient to reverse childhood obesity, experts say.

The assessments, published last month in the American Journal of Preventive Medicine, follow an earlier report on the work of the Healthy Weight Commitment Foundation, 16 big food companies that agreed to reduce by 1.5 trillion the total calories they sold by 2015.

That mark has been exceeded significantly: The companies, which together account for about a third of all the calories in the market place, reduced calories sold from2007 through 2012 by an average of 78 per person, or 6.4 trillion total.

Though noteworthy, it won’t reverse obesity, especially among children, the poor and some minority groups, according to independent evaluations of the project conducted by scientists funded by the Robert Wood Johnson Foundation.

“There has been a cultural shift in this country; especially households with kids have really started buying fewer calories,” Barry Popkin, a professor in the School of Public Health at the University of North Carolina, said by phone. Popkin and Shu Wen Ng, also of the University of North Carolina, wrote the evaluation of what people bought using Nielsen Homescan data of more than 61,000 households.

“The calories purchased has really gone down. And most of the decline is in the kind of food you and I would call junk food or junk beverages,” Popkin said. “Whatwe don’t have is an increase in beans, whole grains, produce” — change that might come if those foods became cheaper relative to packaged products, he said.

“The steepest declines in sales were reported for the least healthy products. The net effect being that as total calories sold declined, there has been a shift toward healthier foods purchased. In other words, both food quantity and quality is starting to improve,” Derek Yach, executive director of the health research firm the Vitality Institute, said in an email.