The future of healthy weight loss could involve party platters filled with mini-sandwiches, because people tend to eat less when the food is broken into smaller pieces, according to a new study.
Even though its nearly impossible to guess the number of jellybeans in a jar, both people and animals use numbers to judge how much food is present.
In a study  presented at the meeting of the Society for the Study of Ingestive Behavior, researchers tested this by training rats to associate two parts of a maze with either a large food pellet, or 30 smaller pellets. Both contained the same amount of calories, but the rats showed a preference for running to the area with the smaller pieces of food.
The researchers also looked at how people respond to portion sizes. They provided over 300 college students with either a whole bagel, or one cut into quartersagain, both the same total calories. Researchers then brought out a complimentary meal, and let the students choose how much to eat.
Students that were given the cut-up bagel ate less calories, both from the bagel and the following meal. This, suggests researchers, is because the greater number of small pieces are more satisfying and filling.
Other studies have shown that how we perceive food can affect how much we eat, and weight loss. One found that edible stop signs  inserted into snack food can prevent overeating. Others have shown that smell  is an important indicator of quantity of food eaten.
The Arizona State University study has not yet been published, so its still preliminary. In the meantime, you can test this out the next time you are having a party. See which of your friends eat morethose with the tiny sandwiches or the ones with the foot-long subs.