(WOIO) - Cities, towns, even the entire state of California have either banned plastic bags, or are taxing people who use them. Here in Ohio,
. But at least one study shows reusable bags have an unintended consequence, which could affect your health.
Heather McNamara has used reusable grocery bags for as long as she can remember, but used to use plastic.
"I would come home with 15 to 20 grocery bags. It is wasteful," McNamara said.
While people might be saving the Earth, researchers found that by using reusable bags, some allow themselves to put more junk food in their shopping carts. The idea surprised McNamara.
"It doesn't make a lot of sense, but it might be true," she said.
Harvard and Duke University
from shoppers. They found that those who use reusable totes buy a lot more organic foods, but also end up filling their carts with more junk food than an average plastic bag user.
Experts call it "Moral Licensing." Dr. Ritesh Saini, a marketing professor, says it happens subconsciously.
"One good thing liberates you, in the sense it gives you a license to engage in something that's not all that great," said Saini.
Moral licensing is not limited to reusable bags alone. It's a phenomena many of us experience in daily life, such as eating a piece of cake after a big workout.
"Seems like we are keeping some kind of a mental clock ticking in our mind," Saini explains. "We are giving ourselves positive or negative brownie points."
Since it is our subconscious at work, we don't even realize when we do it.
To avoid getting into the tote bag trap, it comes down to will power and awareness. McNamara has gained more of that now.
"Definitely, when I go to the grocery store, I will be more aware of what I'm putting in my basket."
Another surprising finding of the study is that people in cities where they are required by law to use reusable grocery bags bought fewer sugary treats.