Q. Can using a smaller plate "trick" you into eating less food?

A. Using smaller serving dishes and plates is an easy way to cut calories. The more food that is on our plates, the more we eat. This is true for children as young as 5 as well as adults.

Penn State researchers studied 3- to 5-year-olds who were fed lunch on two different days at their preschool. Lunches differed only in the portion size of the entree. When given a larger portion, older preschoolers ate more. Younger preschoolers did not. The 3-year-olds ate in response to internal hunger signals, while the 5-year-olds were influenced by the amount served rather than physical hunger.

In a study published in the June 2005 issue of Appetite, Cornell University researchers examined food intake in preschool children for five to seven days in daycare centers. The more food children were served, the more they ate, regardless of what they'd eaten the previous day or how big their breakfast was. Also, the more snacks children were offered, the greater their total daily food and calorie intake.

Similar results have been found in adults. University of Illinois researchers invited 35 graduate students to a party. Half the partiers took a snack of Chex Mix from four-quart serving bowls; the others used two-quart serving bowls. Those using the bigger bowls took 42 percent more than those using the smaller bowls.

Penn State researchers provided 23 adults with all their meals for two 11-day periods. During one of the 11-day periods, standard portion sizes were served. During the second 11-day period, the same meals were served, but the portions were 50 percent larger. Participants consumed an average of 16 percent more calories daily during the large-portion period.

In the early 1900s, the average dinner plate was 7 inches wide. Today it is 10 inches. Many restaurants use 12-inch plates. No wonder it is difficult to gauge an appropriate size portion.

If you use a smaller plate, you will put less food on it. It will look like lots of food, making you think you are getting enough to eat. If you start a child off with a small portion, they can always ask for more if they are not full. Teaching children to rely on their own sense of fullness may help prevent obesity later on.

Amy Tousman is a registered dietitian with the Health Education Center of Straub Clinic & Hospital. Hawai'i experts in traditional medicine, naturopathic medicine and diet take turns writing the Prescriptions column. Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; islandlife@honoluluadvertiser.com; or fax 535-8170. This column is not intended to provide medical advice.