People buy most of their junk food at the supermarket
An analysis of a nationally representative sample of U.S. adults reveals that access to healthy foods in a supermarket does not hinder Americans' consumption of empty calories. In fact, the study found, U.S. adults buy the bulk of their sugar-sweetened beverages and nutrient-poor discretionary foods at supermarkets and grocery stores.
The new findings challenge the "food desert" hypothesis, which posits that a lack of access to supermarkets and grocery stores in some communities worsens the obesity crisis by restricting people's access to healthy foods.
The study, described in the European Journal of Clinical Nutrition, looked at data from 4,204 adults who reported their daily food intake in two, nonconsecutive 24-hour periods in 2011 and 2012. The data came from the National Health and Nutrition Examination Survey. The analysis found that nearly half (46.3 percent) of U.S. adults consume sugar-sweetened beverages and 88.8 percent eat discretionary foods such as cookies, pastries, ice cream, cakes, popcorn and candy on any given day.
Sugar-sweetened beverages add an average 213 calories per day to the diet, the researchers found. Discretionary foods add, on average, 439 calories per day.
The largest portion of those products comes from supermarket shelves, the researchers report.
"More than half of the sugar-sweetened beverages and two-thirds of discretionary foods are purchased in supermarkets and grocery stores," said University of Illinois kinesiology and community health professor Ruopeng An, who led the study.
"Supermarket purchases of these items are about two to four times as large as all the other sources - fast-food restaurants, full-service restaurants, convenience stores, vending machines and other locations - combined."
The food desert hypothesis led the U.S. government to spend almost $500 million since 2011 to improve access to supermarkets and grocery stores in underserved communities. States and municipalities also have made efforts to increase the supply of healthy foods, offering financial incentives to build new grocery stores or to increase the amount of fresh food available in convenience stores and gas stations, for example.
"It is true that supermarkets also are the largest source of healthy food," An said. "But we can't be naïve and think that people only purchase healthy food from supermarkets. They also buy all this junk food from supermarkets and grocery stores."
Adding fruit and vegetables improves the diet, An said. "But from the standpoint of obesity prevention, it is only helpful if people replace junk food with healthy food," he said. "We don't see from our data that the presence of a supermarket has a preventive effect on people's obesity or their junk-food intake."