Building more supermarkets won't solve the obesity crisis

An analysis has challenged the notion that obesity rates can be reduced by improving access to supermarkets offering healthy food, finding that the bulk of soft drinks and junk foods are purchased in supermarkets.

The 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 access to healthy foods.

The study, published in the European Journal of Clinical Nutrition, looked at data from the National Health and Nutrition Examination Survey of 4204 adults who reported their daily food intake in two, non-consecutive 24-hour periods in 2011 and 2012.

The analysis found that nearly half (46.3%) of adults consumed sugar-sweetened beverages and 88.8% ate discretionary foods such as cookies, pastries, ice-cream, cakes, popcorn and candy on any given day.

Sugar-sweetened beverages add an average 891 kJ/day to the diet, the researchers found, while discretionary foods added an average of 1836 kJ/day, with the largest portion of both products coming from supermarket shelves.

“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 has led the US government to spend almost US$500 million since 2011 to improve access to supermarkets and grocery stores in underserved communities. States and municipalities have offered financial incentives to build new grocery stores or to increase the amount of fresh food available in convenience stores and petrol 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 for obesity prevention, it is only helpful if people replace junk food with healthy food.

“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.”