Multiple Pieces of Food Are More Rewarding Than an Equicaloric Single Piece of Food in Both Animals and Humans
Both humans and animals use number as a cue to judge quantities of food, with larger numbers usually associated with larger quantities. Therefore, a food portion cut into multiple, bite-sized pieces may perceptually look more and therefore elicit greater satiation than the same portion presented as a single, large piece.
So a big 1 lb steak doesn't look as filling as 4 quarterpounders.....
Devina Wadhera, the lead author, suggests that "cutting up energy-dense meal foods into smaller pieces may be beneficial to dieters who wish to make their meal more satiating while also maintaining portion control."