Snacking, beverage, ‘super sizing' cited for U.S. obesity
A National Institutes of Health funded study shows how US adults have become obese over the past 30 years. According to the study, conducted by University of North Carolina, Chapel Hill researchers, a combination of eating factors shows how the obesity epidemic has crept up on Americans. Over time, Americans have found more occasions to eat and slowly have been piling the plates with larger portions.
According to the researchers, 'super sizing' and consuming a variety of drinks to stay hydrated - something we're convinced is necessary - has produced an unhealthy, overweight society.
The study is thought to be the first to look at three factors that have ‘super-sized’ America’s waistlines - portion sizes, food energy density and eating frequency.
Barry Popkin, Ph.D., the study’s senior author and W.R. Kenan Jr. Distinguished Professor of Nutrition at the UNC Gillings School of Global Public Health explains, “This study shows how this epidemic has crept up on us. The negative changes in diet, activity and obesity continue and are leading to explosions in health-care costs and are leading us to become a less healthy society. “
The study, published in PloS Medicine was performed "Because obesity causes illness and premature death", according to the journal's editors who say "it is essential that the obesity epidemic is halted and, if possible, reversed.
But before public health policies can be formulated to prevent obesity, we need to understand what is driving the epidemic. Many experts believe that increases in the total daily intake of energy from food and drink, irrespective of changes in physical activity, are enough to explain the observed increases in weight at the population level since the 1970s."
Calorie intake creeps up since 1970’s
In the study, taken from surveys of dietary intake among U.S. adults between 1977–78, 1989–91, 1994–98 and 2003–06, the researchers found Americans are taking in more calories – 570 more calories per 24 hours, to be precise.
Americans consumed 2,374 calories a day in 2003–06, compared to 1,803 in 1977–78.
But where did the calories come from? According to the researchers, we’re eating larger food portions and more often. Most of the increase comes from snacking, more food on the plate and from beverages.
Popkin says, “First, the food industry started ‘super sizing’ our portions, then snacking occasions increased and we were convinced we needed to drink constantly to be hydrated.”
At each survey point, the study showed more calories were being consumed by the respondents. Between 1977–78 and 1989–91, larger eating portions accounted for a 15 calorie increase, with an insignificant amount of calories from eating occasions. But by the next survey point, things changed.
Between 1994–98 and 2003–06, the researchers found 39 more calories a day were being consumed, with portion size accounting for just 1 calorie more a year.
The findings might not be entirely accurate, notes Popkin, due to self-reporting.
Still, the researchers say the study shows ‘super-size’ food portions, beverage consumption and snacking have all contributed to obesity in the U.S. that has crept up over the past 30 years. Preventing obesity may be as simple as snacking less, buying fewer groceries to put on the plate and saying no “Do you want to super-size that?”
Duffey KJ, Popkin BM (2011)
Energy Density, Portion Size, and Eating Occasions: Contributions to Increased Energy Intake in the United States, 1977–2006.
PLoS Med 8(6): e1001050. doi:10.1371/journal.pmed.1001050