The Effect of Number of Pieces of Food on Perceptions of Quantity and Food Intake

Previously we found that subjects ate less from a four-piece bagel than from the same bagel served whole. Here, we determined if subjects differed in their perception of the amount of food based on the number of pieces of food served and measured the effects of these judgments on the amount of food consumed. A total of 213 (140 male, 73 female) undergraduate students with a mean age of 19 years participated in this study. Subjects were shown a whole food and the same food cut into pieces and asked which they perceived to be larger either before or after consuming that food, or not asked at all. We found that subjects ate less from a whole bagel than from a four-piece bagel. Furthermore, significantly more subjects perceived the whole bagel to be more food when asked this question after consumption of the bagel than before. People may be more familiar with the amount of satiation expected from a whole bagel than the four-piece bagel and this perceptual bias may be influenced by recent exposure to food, which ultimately may affect food intake.