The research – to be presented at the Annual Meeting of the Society for the Study of Ingestive Behavior (SSIB) – investigated how the size and number of food pieces impacted satiety and reward mechanisms, revealing that that both animals and humans find multiple pieces of food to be more filling and rewarding than a single-piece portion of food with equal calorific value.
“Perhaps food in pieces appears bigger and is therefore more rewarding and satiating to both animals and humans,” said the researchers, led by Devina Wadhera of Arizona State University, USA.
Wadhera noted that 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,” explained the team.
"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," suggested Wadhera.
In the first part of the study, food-restricted rats were trained to associate one T-maze arm with 30 (10 mg) pellets and another with 1 (300 mg) food pellet.
Following this training, they were given 12 trials where arm choice and speed to the chosen arm were measured.
The results showed that rats preferred and also ran faster for the arm associated with the multiple (30) 10 mg pellets than that associated with the single 300 mg food pellet.
Wadhera said the finding shows that foods in greater numbers may be more rewarding to animals than an equicaloric, single food pellet.
In the second part of the study, a sample of 301 college students was given a pre-measured 82 gram food portion (bagel) uncut or cut into quarters.
Twenty minutes after the bagel was consumed, subjects were told that they could eat as much or as little from a complimentary test lunch (test meal). Any leftover bagel and test meal was then recorded.
Subjects who received the single, uncut bagel ate more calories from both the bagel and the test meal than those who received the multiple-piece bagel, said the researchers.
“This shows that food cut into multiple pieces may be more satiating than a single, uncut portion of food,” they said.