Shoppers who bring their own reusable bags tend to be environmentally conscientious, but they seem to have other common traits as well. According to a recent study, they have a greater preference for organic items—but also for junk food.
Selecting more naturally grown products makes sense, as it falls in line with an overall awareness about the environment, but researchers believe that bringing personal bags also leads to a sense of virtuousness and a belief that they are doing something good for the world—which is why those shoppers are more likely to indulge in less healthy foods like chips and cookies.
To arrive at these findings, nearly two years of data at one California grocery store were analyzed, comparing purchases made by the same loyalty cardholders when they had their own bags or not.
In a second component, a group of online participants—half who were told they had personal bags and half who did not—were asked to provide a list of ten items they would buy in a hypothetical grocery scenario.
The team believes this study can influence the way stores market, price, and place their products based on their customers' reusable bag habits.
See stores around the world that use reusable bags:
Stores with reusable bags
Study: Shoppers with their own reusable bags shown to buy more junk food
Reusable shopping bags are offered for sale at new Walmart Neighborhood Market, opening its 34,000 square foot store in the Chinatown district of Los Angeles Thursday, Sept. 19, 2013. (AP Photo/Nick Ut)
Isaiah McDaniel bags groceries into a customer's cloth bags at PCC Natural Market Tuesday, Jan. 15, 2008, in Seattle. Paper or plastic could become passe under a measure being pushed by one lawmaker who says plastic grocery bags harm the environment and waste resources. Rep. Maralyn Chase, D-Shoreline, has sponsored a bill that would require grocery stores to provide bags that are made from recyclable paper, compostable plastic, reusable textile materials like canvas, or reusable plastic that is at least 0.09 inches thick. (AP Photo/Elaine Thompson)
An environmentalist uses a reusable bag at a grocery in suburban Quezon City, north of Manila, Philippines, Monday, Sept. 4, 2006. The environment group is calling on the public to use a traditional native bags and reusable items to help in the fight against pollution from the excessive use of plastics. (AP Photo/Aaron Favila)
San Francisco Supervisor Ross Mirkarimi hands out canvas shopping bags, Tuesday, March 27, 2007, in San Francisco. San Francisco's Board of Supervisors on Tuesday is to consider passing an ordinance that would require large supermarkets and pharmacies in the city to replace non-biodegradable plastic bags with reusable or recyclable bags, a move that would make San Francisco the first city in the U.S. to introduce such a ban. Mirkarimi, who sponsored the original version of the ordinance, said the proposal has the support of most supervisors, the city's garbage disposal contractor, and even many smaller retailers, who won't have to comply with the ban. (AP Photo/Ben Margot)
Davon Johnson bags groceries into a customer's canvas bags at a Giant supermarket in Washington on Friday, Jan. 18, 2008. The store has both plastic and paper bags available, and also sells reusable bags in the store. Faced with a growing push in some states and cities to ban or limit use of the plastic bag, often depicted as a poster child for litter, many grocers are urging consumers to bring their own bags or to reuse or recycle the plastic ones. (AP Photo/Jacquelyn Martin)
A woman carries a reusable carrier bag as she exits a shopping centre in Faches-Thumesnil, northern France, on June 27, 2014. A governmental amendment added to the biodiversity bill on June 25, aims for a total ban on single-use plastic bags. AFP PHOTO/PHILIPPE HUGUEN (Photo credit should read PHILIPPE HUGUEN/AFP/Getty Images)
PASADENA, CA - APRIL 22: Cashier Bianca Kurian (L) hands out free reusable grocery bags at a Whole Foods Market natural and organic foods stores which is ending the use of disposable plastic grocery bags in its 270 stores in the US Canada and UK on Earth Day, April 22, 2008 in Pasadena California. The use of reusable bags has increased since a statewide plastic bag recycling law was enacted in July 2007 requiring grocers to provide in-store plastic bag recycling and to sell reusable shopping bags. Some communities have banned disposable single-use plastic shopping bags because they don't break down in landfills, and clog waterways, endangering wildlife, and are a major source of litter. (Photo by David McNew/Getty Images)
WUHAN, CHINA - APRIL 1: (CHINA OUT) Customers pack goods with reusable shopping bags in a super market on April 1, 2008 in Wuhan of Hubei Province, China. The Chinese government has announced a nationwide ban on stores distributing free ultra-thin plastic bags from June 1, 2008. The new rule says all retailers have to clearly indicate the price of their plastic bags and charge customers for the bags. Chinese people use up to three billion plastic bags a day, which caused about 5 million tonnes of crude oil used to make plastic bags for packaging every year, according to reports. (Photo by China Photos/Getty Images)
LOS ANGELES, CA - APRIL 21: Food 4 Less grocery store general clerk Xochil Montenegro (R) hands out a free reusable shopping bag, supplied by the California Grocers Association (CGA) and the City of Los Angeles, to customer Jesus Rios in observance of Earth Day, on the eve of Earth Day, April 21, 2008 in Los Angeles, California. During the two-day program, 50,000 bags are being handed out at about 40 grocery stores to encourage consumers to use reusable bags instead of disposable plastic or paper bags. The use of reusable bag has increased since a statewide plastic bag recycling law was enacted in July 2007 requiring grocers to provide in-store plastic bag recycling and to sell reusable shopping bags. Some communities have banned disposable plastic grocery bags. The free bags provided by the CGA and the city are made of 100% recycled water, soda and food containers. (Photo by David McNew/Getty Images)
LONDON - FEBRUARY 29: A man carries a TESCO's re-usable bag on February 29, 2008 in London, England. The Prime Minister Gordon Brown has stated that he will force retailers to help reduce the use of plastic bags if they do not do so voluntarily. (Photo by Cate Gillon/Getty Images)
LONDON - FEBRUARY 29: A lady sits her M&S re-usable bag down with a plastic bag inside on February 29, 2008 in London, England. The Prime Minister Gordon Brown has stated that he will force retailers to help reduce the use of plastic bags if they do not do so voluntarily. Marks & Spencers have said they will start to charge for their plastic bags in food departments. (Photo by Cate Gillon/Getty Images)