Walmart is now the largest grocery store chain in the country, and a new study says that the more supercenters the company opens, the heavier the people living nearby become.

From the Montreal Gazette:

The researchers found that one new Walmart supercentre per 100,000 residents meant an average weight gain of 1.5 pounds per person sometime over a 10-year period dating from the store’s opening. It also boosted the obesity rate by 2.3 percentage points, meaning that for every 100 people, two who weren’t obese ended up in that category after a superstore opened.

One of the study’s authors says the root cause is both the low cost of food at Walmart and the quality of the food sold there.

“I think the most obvious story is that Walmart lowers the price of foods and a lot of the foods it has big price advantages on are the processed, inner-aisle types of food that aren’t that good for you,” explains the researcher from the University of North Carolina, Greensboro.

Additionally, he believes that Walmart’s price-slashing has a ripple effect at other stores: “It’s not just about Walmart underselling the competitor. It’s about the competitors cutting their prices in response to competition from Walmart. Someone might never step foot in a Walmart, but they still might pay less for their food.”

The study, which will be published in the March issue of the Journal of Urban Economics, found that women, low-income families and those in less densely populated areas are the ones most likely to experience weight gain after a new Walmart opens.

“We don’t want people to look at this and immediately say Walmart is evil. We want people to realize this is one of many things that are going on, and maybe some are good and some are bad,” said the study’s co-author. “Certainly our results should not be taken as, ‘Ban all Walmarts.’ It’s part of a very broad debate.”

Packing on the pounds blamed on . . . weight for it . . . Walmart [Montreal Gazette]

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.