It sounds ridiculously simple, but a new study of eating habits suggests that using smaller serving utensils may actually help people eat less without realizing it.

Researchers threw an ice cream social to test whether oversized bowls and extra-large ice-cream scoops caused partygoers to dish up more dessert.

"Just doubling the size of someone's bowl increased how much people took by 31 percent," said lead author Brian Wansink, director of the Food and Brand Lab at Cornell University."We also saw that giving people a scoop that was a little bit larger increased things by about 14.5 percent," said Wansink, whose study appears in the September issue of the American Journal of Preventive Medicine.

Eighty-five unaware food and nutrition experts gathered at the ice cream social to celebrate a colleague's achievement. The researchers randomly handed out either 17-ounce or 34-ounce bowls, and provided either 2-ounce or 3-ounce serving scoops. The guests then served themselves.

Diet experts and nutritionist have already documented that subtle environmental clues can influence food consumption. These include music, temperature and whether we're with someone who's eating faster or slower than we are, Wansink said. The visual illusion caused by tableware may be another environmental clue that affects food choice. All but three of the partygoers finished all the ice cream they had put in their bowl.

Each bowl of ice cream was weighed before it was consumed, and each diner was asked to estimate how much ice cream and calories they had taken. Wansink said the study participants — who were, after all, nutrition experts — judged the size and calorie-counts of their portions better than the average person would. But that knowledge did not keep them from taking more ice cream when they were given larger bowls and spoons.

"The fact that even they end up being tripped up by these cues just helps to show how ubiquitous and how subversive these illusions can be," said Wansink.