Though media stories about obesity are still prevalent, what gets left out is that American obesity rates have stabilized.

It's unclear why. Some papers claim it was due to the lingering stagnant economy. People go out to eat less, they shop smarter. But a new paper claims it is health food advocacy that has done its job and the leveling off (and, in some demographics, decline) started during the better economy of the Bush years, when  more information and efforts were aimed at producing healthier food choices and eating habits.

"We found U.S. consumers changed their eating and food purchasing habits significantly beginning in 2003, when the economy was robust, and continued these habits to the present," said first author Shu Wen Ng, assistant professor of nutrition at The University of North Carolina at Chapel Hill's Gillings School of Global Public Health. "These changes in food habits persist independent of economic conditions linked with the Great Recession or food prices. The calorie consumption was declining at a rate of about 34 calories less per year among children aged 2-18 between 2003 and 2010 (vs. only 14 kcal/day among adults decline per year). The declines in food purchases after adjusting for all the economic changes was also at a rate of 34 kcal/capita per year among households with children between 2000 and 2011."

Ng adds that this dramatic turn in dietary behavior is more likely the outcome of sustained and persistent public health efforts aimed at raising awareness about the importance of healthy eating, providing better information about food choices, and discouraging unhealthy dietary choices.

The researchers used both nationally representative dietary intake data along with longitudinal data on daily food purchases from hundreds of thousands of Americans. The study samples included combined datasets from the NHANES study, which covered households comprising 13,422 children and 10,791 adults from 2003-2011; and the Nielsen Homescan Panel, which contains food purchase data from 57,298 households with children and 108,932 households without children.

The data show that calories declined more among children than adults and that the proportional decline in calories was greatest among calories from beverages.

Researchers then turned their analysis to examining how much of this decline was the result of the Great Recession and the year of large increases in food prices preceding the recession. If we looked only at the impact of the increases in unemployment related to the Great Recession, the study showed that each 1 percent increase in the unemployment rate in the area where respondents lived was associated with a 2-4 kcal/capita/day increase in calories purchased. This is small relative to the major declines that occurred over time.

"This analysis is significant as we found the largest declines were among households with children. However these declines did not occur uniformly. There were no significant declines in caloric intake observed among adolescents (12-18y), non-Hispanic black children and those whose parents did not complete high school," said Barry Popkin, Distinguished Professor of nutrition at UNC Gillings. "This suggests that certain subpopulations are still unable or unwilling to make these dietary changes."

While Popkin noted that the specific contributors for these changes in behavior are not quantifiable, he suggested that greater attention by the public health community and journalists to obesity overall, particularly to soft drinks and other high-calorie sugary beverages and the changes made by food companies or retailers may have produced significant rises in the awareness among consumers about the role of food, particularly when it comes to caloric beverages in affecting obesity and health.



Citation: Shu Wen Ng, Meghan M Slining, and Barry M Popkin, 'Turning point for US diets? Recessionary effects or behavioral shifts in foods purchased and consumed', Am J Clin Nutr March 2014 ajcn.072892 doi: 10.3945/​ajcn.113.072892. Source: University of North Carolina at Chapel Hill