In a study performed by Brian Wansink (author of Mindless Eating) and his graduate students, he proves that the larger the container put before you, the more you’ll eat.

Wansink and his graduate students offered free popcorn to moviegoers one afternoon. Every person who bought a ticket was given either a medium-size or large-size bucket of popcorn. The catch? The popcorn was stale, made 5 days earlier. As the movie progressed, people would eat some, put the bucket down, then pick it up a little while later.

As Wansink notes:

“It might not have been good enough to eat all at once, but they couldn’t leave it alone.”

When the movie ended, the viewers given the large buckets of popcorn were asked the following:

“Some people tonight were given medium-size buckets of popcorn, and others, like yourself, were given these large-size buckets. We have found that the average person who is given a large-size container eats more than if they are given a medium-size container. Do you think you ate more because you had the large size?”

Most disagreed, thinking they weren’t that easily led.

Well, the proof was in the pudding…or in this case the popcorn. The large-size popcorn group ate 53% more popcorn than the medium-size group, whether they wanted to believe it or not. The test was run repeatedly, from Pennsylvania to Illinois to Iowa, and the results remained the same: people eat more when given a bigger container.

And this was stale popcorn! One viewer said it was like eating “Styrofoam packing peanuts.” People ate a considerable amount from either group, regardless of the unpleasant taste.

Moral of the story? Size counts even when taste isn’t that great. It’s not the only factor that comes into play when we overeat but its something to consider. This is why we need to be on guard when we see the phrases “all you can eat” and “jumbo!”