University Park, Pa -- A Penn State study has shown that portion control is as important for developing healthy eating habits among preschoolers as it is for adults.
In the first published study of the effect of portion size on food intake in preschoolers, 3-year-olds offered a larger than usual serving of macaroni and cheese resisted the opportunity to overeat -- but 5-year-olds ate up.
Dr. Barbara J. Rolls, who holds Penn State's Guthrie Chair of Nutrition in the College of Health and Human Development, is lead author of the study. She says, "Young children have a natural capacity to self-regulate their food intake but our study indicates that sometime between the age of 3 and 5 years of age, they learn to ignore their internal hunger signals and respond instead to other cues, including portion size.
"For children who have learned to be responsive to environmental cues instead of hunger, offering them large portions can promote overeating and produce overweight," she adds.
Rolls, who is co-author of the new best selling weight management book, "Volumetrics: Feel Full on Fewer Calories," adds, "Our study strengthens the link between the increasing availability of 'supersized' portions in restaurants and grocery stores and the increasing prevalence of overweight among U.S. adults and children."
Several previous studies at Penn State and elsewhere have shown that adults eat more when served large portions. The current study, the first with children, shows that the learned behavior of ignoring internal hunger cues has very early roots, reaching back to the preschool period.
Portion control in our overfed society is as important for preschoolers as it is for adults, Rolls adds.
The study is detailed in a paper, "Serving Portion Size Influences 5-year-old But Not 3-year-old Children's Food Intakes," in the current issue of the Journal of the American Dietetic Association. Her co-authors are Dr. Dianne Engell, who spent a sabbatical at Penn State, and Dr. Leann L. Birch, professor and head of the Department of Human Development and Family Studies.
Thirty-two preschool children enrolled in daycare programs at Penn State's University Child Development Lab participated in the study with their parents' permission. There were 8 boys and 8 girls who were about 3 and half years old and 6 boys and 10 girls who were about 5. On three different days, during their regular lunch period, the children were served either a small, medium or large portion of macaroni and cheese, carrot sticks, applesauce and milk.
For the younger children, the macaroni and cheese portions were two thirds cup, one and one-sixth cup and one and two-thirds cup respectively. The older children received either one-cup in the small portion, one and a half cups in the medium portion and 2 cups in the large portion. The medium size portion was based on the U.S. Department of Agriculture recommended serving size for 3- and 5-year olds.
All portions were served in the same size bowl, and all food was weighed before and after lunch to determine the amount the children consumed.
The older children, but not the younger children, ate more of the macaroni and cheese when served the large portion. The older children, but not the younger children, also consumed more calories from the entire meal when served the larger portion of macaroni and cheese.
"We don't have all of the answers yet about why children begin to ignore their internal hunger cues," Dr. Rolls notes. "However, it's clear from this study that serving children larger than recommended portions encourages them to eat more than is necessary or prudent for their long term good health."
EDITORS: Dr. Rolls is at (814) 863-8482 or e-mail bjr4@psu.edu
Journal
Journal of the American Dietetic Association