Object recognition may distort size perception

Effects of Food Environments and Eating Environments on Consumers’ Food Consumption Volume

Even though the influences of eating environments and the food environments on consumption have been discussed, little has been done to examine whether the food environments would be influenced by the eating environments. For example, the size of plate has been proved to have impact on consumers’ consumption volume; it is still unknown whether the eating environment would interact with the food environment and in turn influences consumers’ consumption volume. This research explores the underlying mechanisms how consumers are influenced by the size of bowl when they consume food. In addition, eating environments are also incorporated to discuss their effects on the relationship between bowl size and consumers’ consumption volume. The results indicate people who receive a large bowl with large chopsticks exhibit greater food consumption than those who receive a small bowl with small chopsticks. However, when people use tableware inconsistently, they exhibit similar food consumption. Under bright illumination, people given large bowls with large chopsticks exhibit greater food consumption than those given small bowls with small chopsticks; however, when people use inconsistently sized tableware, they exhibit similar food consumption. Under dim illumination, no significant differences in food consumption amount are evident in association with bowl and chopstick sizes.

Food portion estimation by children with obesity: the effects of estimation method and food type

Several factors influence children's ability to report accurate information about their dietary intake. To date, one understudied area of dietary assessment research relates to children's ability to estimate portion sizes of food. The purpose of this cross-sectional research was to examine food portion size estimation accuracy in 7- to 18-year-old children with obesity. Two within-subject experiments (Experiment 1: n=28, Experiment 2: n=27) were conducted in Edmonton, Alberta, Canada, during 2007-2008. Three types of portion size measurement aids (PSMAs) (eg, measuring cups and spoons, household objects [full and half-sized], and modeling clay) were counterbalanced in a Latin Square design for participants to estimate four types of foods (ie, solid, liquid, amorphous pieces, and amorphous masses). Analyses of variance conducted on percent of signed and absolute errors yielded significant PSMA type×food type interactions (P<0.01) in both experiments. Across all food types, for Experiments 1 and 2, measuring cups and spoons produced the least accurate estimates with respect to absolute error (54.2% and 53.1%, respectively), whereas modeling clay produced the most accurate estimates (40.6% and 33.2%, respectively). Half sizes of household objects also yielded enhanced accuracy (47.9% to 37.2%). Finally, there were significant differences in accuracy between amorphous pieces (eg, grapes) vs amorphous masses (eg, mashed potatoes; P<0.01), indicating that there are qualitative differences in how different amorphous foods are estimated. These data are relevant when collecting food intake data from children with obesity and indicate that different PSMAs may be needed to optimize food portion size estimation accuracy for different food types.

Is Size Misperception of Targets Simply Justification for Poor Performance?

Recent studies show that those who perform poorly on sporting activities involving targets recall the target as smaller than do better performers. Some have attributed the effect to action-specific perception, suggesting perception is influenced directly by how one interacts with an object. We proposed that underestimation of target size may instead serve as a justification for poor performance. We found that inaccurate dart throwers, given an excuse that the darts were of poor quality, were less likely to recall the target as smaller. The findings extend research indicating that perception is influenced by motivational factors, and provide further evidence that size estimates can be distorted by memory errors.

Ice cream illusions bowls, spoons, and self-served portion sizes

BACKGROUND

Because people eat most of what they serve themselves, any contextual cues that lead them to over-serve should lead them to over-eat. In building on the size-contrast illusion, this research examines whether the size of a bowl or serving spoon unknowingly biases how much a person serves and eats.

METHODS

The 2 x 2 between-subjects design involved 85 nutrition experts who were attending an ice cream social to celebrate the success of a colleague in 2002. They were randomly given either a smaller (17 oz) or a larger (34 oz) bowl and either a smaller (2 oz) or larger (3 oz) ice cream scoop. After serving themselves, they completed a brief survey as their ice cream was weighed. The analysis was conducted in 2003.

RESULTS

Even when nutrition experts were given a larger bowl, they served themselves 31.0% more (6.25 vs 4.77 oz, F(1, 80) = 8.05, p < 0.01) without being aware of it. Their servings increased by 14.5% when they were given a larger serving spoon (5.77 vs 5.04 oz, F(1, 80)=2.70, p = 0.10).

CONCLUSIONS

People could try using the size of their bowls and possibly serving spoons to help them better control how much they consume. Those interested in losing weight should use smaller bowls and spoons, while those needing to gain weight--such as the undernourished or aged--could be encouraged to use larger ones. Epidemiologic implications are discussed.

Depiction of an Object's Size in Drawings Subsequent to Interaction with the Object

Subsequent representation of the size of the object in a visuomotor activity was evaluated after an object was used differentially in two ways. 25 female and 17 male students volunteered from general psychology courses and were randomly assigned to a condition in which participants used a small teaspoon to remove sand from a ladle or simply moved the ladle. Those who removed sand drew a representation of a ladle that was taller than did participants who moved the ladle. It appears, given the time-consuming activity of removing sand, the ladle appeared to contain more sand and seemed larger. Findings suggest that the way an object was used may distort memory of its size and that subsequent representation of the size in a visuomotor task can be influenced by that memory.