When Chilly Billy’s owner Bill Marker looks around his frozen yogurt shop, he said he rarely sees people throw away containers that aren’t empty. That could be because customers can choose their own portion size.

University of Minnesota researchers found that when restaurants provide flexible portion sizes, like Chilly Billy’s does, customers eat healthier portion sizes, have improved satisfaction and waste less food.

“People really don’t waste anything, as far as I can see, and I think that’s partially because of the pay-by-the-weight system,” Marker said.

After the Natural Resources Defense Council reported in 2012 that Americans waste about 40 percent of food, with restaurant portion sizes being a substantial contributor, University researchers set out with a grant from the Food Policy Research Center to find a healthy solution for businesses that would help reduce waste.

The researchers collected data from a commercial restaurant and a nonprofit cafeteria, which they said they couldn’t disclose, before and after implementing smaller portion sizes for some dishes. The preliminary research found more than a quarter of customers were willing to buy the smaller portions and could reduce almost 90 percent of meat waste.

Sarah Berkowitz, a nutrition graduate student who contributed to the research, said both eateries have decided to continue offering the reduced portion sizes.

“The businesses weren’t sure how their customers were going to react and if it was going to work for them, but it did,” she said.

Providing flexible portion sizes, Berkowitz said, could be a good option for small businesses that want to draw in more health-conscious customers and produce less waste.

Marni Surdy, a sustainable design junior who waitresses at Annie’s Parlour in Dinkytown, said she can typically fill a plate with
leftover food when she cleans up any given table.

Annie’s offers half and full sizes for their large malts and fries, but only has one size for burgers and entrées. Surdy said she usually warns her tables before they order a full-size basket of fries that the basket can feed four to six people.

“If people get a full [size], there’s almost always food left over,” Surdy said.

She estimates that about two thirds of her customers order the half-size option.

Biomedical engineering sophomore Amanda Dahl said she sometimes chooses the larger portioned option so she has leftovers to bring home for lunch the next day. But on days when she isn’t heading home, she chooses a smaller option if it’s available, she said, because she knows she won’t finish a larger size.

Smaller portion sizes are often better options for students, Berkowitz said, because they are cheaper, healthier and better for the environment.

“It depends on the restaurant, but overall I think restaurants should consider it,” Dahl said, “just because it gives freedom to the customers and it’s really no different for the cooks to make it.”