Serving Bowl Selection Biases Amount of Food Served

Abstract

Background and objectives: Recent studies have emphasized that a size-contrast illusion leads unknowingly consumers to serve and eat more food when using larger dinner plates and serving spoons. Such a size-contrast illusion would not, however, be operating when one serves from a common serving bowl. Exploring if and how serving bowls might bias intake offers the potential to uncover other mechanisms through which environmental cues influence behavior.

Methods: In this between-subjects experiment, eighty six participants served themselves pasta either from a large serving bowl (about 6.9 liter capacity) or from a medium-sized serving bowl (about 3.8 liter capacity). After eating their fill, they completed a questionnaire, and their remaining pasta was weighted.

Results: When given a larger serving bowl, diners served 78% more pasta (425.9 versus 283.9, p< 0.001), even though they did not rate the food as any tastier, or otherwise notable (all ps>0.24). In contrast to studies involving large-sized plates and spoons, people serving from larger bowls appeared to realize they served more and rated themselves as marginally more full afterwards.

Discussion: These findings again highlight the role that external cues play in food consumption and show the importance of considering the size of serving bowls containing multiple portions in relation to nutrition education on weight loss and maintenance. Instead of a size-contrast illusion driving the results, a different mechanism, such as consumption norms may operate on such occasions.

Keywords: Serving bowl size; portion size, food intake, external cues