Portion Size Study in Young Children

Snacks served in a large portion size increase energy intake in preschool-aged children, according to a recent study from The University of Tennessee at Knoxville and published in the Journal of the American Dietetic Association.

Snacks served in a large portion size increase energy intake in preschool-aged children, according to a recent study from The University of Tennessee at Knoxville and published in the Journal of the American Dietetic Association. 

The study looked at children between the ages of two and five attending full day preschool at the Early Learning Center on the Tennessee Knoxville campus. Three hours following a family style lunch, the children were asked to evaluate their hunger level as well as their food likes and dislikes. Then they were given a snack, asked not to share it with others, and to eat as little or as much of the snack as they liked. 

The amount of the snack consumed was determined by subtracting post-snack weight from pre-snack weight. Additionally, snack energy intake was determined using the Nutrition Data System for Research software. 

While greater energy was consumed in the large portions as compared to the small portions, there was no main effect of energy density on energy intake. However, the effect of portion size on snack intake was significant. Regardless of energy density, energy intake increased when snacks were offered in larger portion size.

“Portion size is an environmental cue. The cue triggers the behavior of eating. A larger cue most likely triggers a larger response. Eating continues because the food is there,” says Shannon Looney, MPH, RD, Doctoral Student in the Department of Nutrition, University of Tennessee, Knoxville. 

Interestingly, previous studies on entrees in this area have found energy intake to be substantially affected by energy density, but not portion size – and found no interaction between energy density and portion size in preschool-aged children. What makes this current study significant is that it looks at snacks specifically. Since young children consumer a large amount of energy from snacks, it was important to look at the relationship that snack portion size and energy density has on energy intake in this age group. 

“Investigating snack consumption is important because there has been an increase in snack consumption. Consuming more snacks may contribute to greater caloric intake. Additionally, many snack foods are energy-dense providing extra calories which, over time, can impact weight status,” says Looney.

With child obesity on the rise, it is crucial that food industry professionals gain a greater understanding of dietary environmental factors that influence energy intake. As children may consume multiple snacks within a day and week, controlling snack portion size may be an environmental strategy that can reduce excessive caloric intake in young children.

“Retailers have and need to continue to provide snacks in appropriate portions. Currently pre-portioned snack foods are more expensive, thus, retailers may consider reducing the cost of pre-portioned snacks,” says Looney.   

The influence of dietary environmental factors on weight status is important in the battle against obesity. Looney adds that, based on this study, the results can not be generalized to the adult population. Nevertheless, the same study could be designed for adults to investigate the impact of portion size and energy density of snack foods.