It seems like a simple equation: Small plate equals less food equals lower calories. But it doesn’t necessarily add up.

That was one of the findings of a study published by Meena Shah, professor of kinesiology in the Harris College of Nursing & Health Sciences, and colleagues. The findings were published in the Journal of Human Nutrition and Dietetics in December.

“Plate size does not affect energy intake in either the normal weight or overweight or obese subjects,” Shah says.

The study was conducted by Rebecca Schroeder ’10 when she was an undergraduate at TCU. Later, Walker Winn ’10 joined the effort. Beverley Adams-Huet, faculty and biostatistician from the UT Southwestern Medical Center at Dallas developed the statistical modeling and helped analyze and interpret some of the data.

The study examined 10 normal-weight women and 10 overweight or obese women over two different days at lunch. Subjects were randomly assigned to consume lunch using either a small (21.6 cm) or large (27.4 cm) plate.

The meal, which consisted of spaghetti and tomato sauce, was served in an individual serving bowl. Each subject was asked to self-serve the food from the bowl onto the assigned plate and instructed to eat until satisfied. The meal was consumed alone and without any distractions. During the second lunch, each subject went through the same procedure but using the alternative size plate.

“Plate size did not have any impact on energy intake, possibly because people eat until they are full regardless of what size tableware they use.” Shah says.

“Overweight or obese subjects reported lower levels of hunger and desire to eat before the meals and felt less full after the meals compared to normal weight subjects, despite there being no difference in energy consumption between the two groups,” Shah adds. “This suggests that overweight or obese individuals may have a lower ability to sense hunger and fullness than normal-weigh individuals.”