Obesity has become an epidemic in the U.S.. Unlike popular belief that it is the monopoly of certain ethnic groups or those poorly educated, obesity is actually hitting all groups of Americans, said a new report.
All Americans have been getting fatter at about the same rate for the past 25 years, even as the nation saw more leisure time, more fruit and vegetables available, and more exercise.
Since 1970, the average per capita consumption of calories of Americans has risen by about 20 percent, while at the same time there has been a sharp drop in the cost of food as a proportion of disposable income.
“Not only has food been getting cheaper, but it is easier to acquire and easier to prepare,” said Roland Sturm, lead author of the report and a senior economist at RAND, a nonprofit research organization. “It’s not just that we may be eating more high-calorie food, but we are eating more of all types of food.”
Many factors have been blamed for a growing incidence of obesity in the U.S., including fast food, suburban sprawl, the size of prepared meals, poverty, affluence, a lack of exercise and a shortage of access to healthy foods.
Analyzing economic factors that contribute to obesity, Sturm and co-author Ruopeng An found that the cause of obesity is driven by environmental factors that affect all groups.
Americans now have the cheapest food in history, when measured as a fraction of disposal income.
“Not only has the cost of food dropped, but it has become even more available,” An said. “So a smaller share of Americans’ disposable income now buys many more calories.”
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The decline of food expenditures relative to income becomes more dramatic when considering quality factors, such as greater convenience, reduced time needed for preparation, increased variety and the ubiquitous availability of food.
Sturm and An say that effective economic policies to curb obesity remain elusive.
Imposing taxes on foods with low-nutritional value could nudge behavior toward healthier diets, as might subsidies or discounts for healthier foods. But political and popular support for such approaches has been low.
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“The high cost of healthy food may not be the problem as far as obesity is concerned, rather it is the excess availability and affordability of all types of food,” Sturm said. “We need to consider strategies that replace calorie-dense foods with fruits and vegetables, rather than just add fruits and vegetables to the diet.”
“Obesity and economic environments,” Roland Sturm and Ruopeng An, CA: A Cancer Journal for Clinicians online 22 MAY 2014