Research by Brian Wansink, a professor of marketing and nutritional science at the University of Illinois at Urbana-Champaign, challenges the conventional notion that a person's ability to control eating and stick to a successful diet has solely to do with willpower.
Little-understood contextual cues -- such as how food is displayed and its variety of colors -- can lead people to overindulge and unknowingly bulk up, he says in an article he wrote that has been published in the Journal of Consumer Research.
For example, adults offered six colored flavors of jellybeans mixed together in the same bowl ate 69 percent more than when the colors were each placed in separate bowls.
In another study, moviegoers given M&Ms in 10 colors ate 43 percent more than those offered the same number of M&Ms in seven colors. Wansink and co-author Barbara E. Kahn, a professor of marketing at the University of Pennsylvania, concluded that not just variety, but the perception of variety, stimulates how much a person consumes.
"People eat with their eyes, and their eyes trick their stomachs," Wansink said in an interview. "If we think there's more variety in a candy dish or on a buffet table, we will eat more. The more colors we see, the more we eat."
In the case of jellybeans, a variety of flavors in a bowl was greeted by such comments as "looks really colorful," "feels enjoyable," "satisfied as I ate" and "gives me at least one flavor that I like."
An earlier study by Wansink found that moviegoers given an extra-large bucket of popcorn will eat up to 50 percent more than those given a container one size smaller -- even when the popcorn is stale.
Other studies have found that, hungry or not, office employees will eat more if their desks are stocked with food, or if the food is nearby, or if the package is open, or if th
Contact: Mark Reutter, Business & Law Editor
University of Illinois at Urbana-Champaign