Children who become familiar with a snack food will expect it to be more filling, finds a new study.
This finding is important because it reveals one way in which children over-consume snack foods and increase their risk of becoming overweight.
Children are at risk of obesity due to consumption of energy-rich snack foods that are often high in calories and associated with weight gain.
The study led by psychologists at the University of Bristol aimed to establish whether familiarity with snack foods would change the children's expectations about fullness.
The researchers found that familiarity helps children (11- to 12-year-olds) to predict the fullness that is associated with snack foods, which, in turn, informs appropriate decisions about portion sizes.
The team also discovered that children who were infrequent consumers tended to rely on the physical appearance of the food, for example volume, in their judgments about fullness.
This strategy would be expected to promote selection of larger portion sizes.
"Presenting children with a wide variety of different snack food products may make it difficult to predict their fullness. Our study suggests that if parents choose to give snack foods to their children, they may wish to stick to the same products," said Dr Charlotte Hardman, one of the authors from the Nutrition and Behaviour Unit in the University's School of Experimental Psychology.
The findings were published in the American Journal of Clinical Nutrition.