Big Portions Lead To Overeating, Even If Food Tastes Bad

Large portions push people to overeat -- even if it's food they don't like, according to a new study.

Researchers gave moviegoers stale popcorn in big buckets, and they ate 34 percent more than those given the same stale popcorn in medium-sized containers.

Tasty food created even larger appetites: When served fresh popcorn in large tubs, people ate 45 percent more than those given fresh popcorn in medium-sized containers.

"We're finding that portion size can influence intake as much as taste," said researcher Brian Wansink, a professor of marketing and applied economics at Cornell University. "Large packages and containers can lead to overeating foods we do not even find appealing."

The study is published in the September/October issue of the Journal of Nutrition Education and Behavior.

The researchers gave 158 moviegoers either medium (4.2 oz) or large (8.4 oz) tubs of free popcorn that was either fresh or 14 days old. The researchers asked the moviegoers to describe the popcorn after the movie, and they weighed how much popcorn was left in the containers.

As expected, the 14-day-old popcorn was described with such remarks as "stale" and "it was terrible."

When the moviegoers were asked if they thought they ate more because of the size of the container, 77 percent of those given the large tubs said they would have eaten the same amount if given a medium container.

"This means that the moviegoers were unaware that the exceptional amount they ate was due to the size of the container," Wansink said in a news release.

But there's a silver lining to the findings: Portion sizes can be used to increase the consumption of less appetizing, but healthy foods, such as raw vegetables, Wansink said.

"While a small bowl of raw carrots might make for a good afternoon snack, a large bowl might be even better," he said.