Abstract
OBJECTIVES: Food liking influences food choice and the most-liked foods are often energy dense. Previous studies found that both food liking and energy density predicted the size of portions selected by adults. To extend these findings, we investigated the independent and combined effects of food liking and energy density on portion selection in children. METHODS: In two laboratories, 67 children aged 7–16 years (49% girls; 16% with overweight or obesity) completed a computerized survey to assess characteristics of 20 common foods. Children were shown images of the foods and used 100-point scales to rate how much they liked the food (liking) and how much they would eat at a specified meal (portion selection). The energy density (ED) of the foods ranged from 0.3 to 4.9 kcal/g. The survey displayed five images of food amounts at 10%, 30%, 50%, 70%, and 90% of the scale. The portion size of the 50% image was used as the reference amount and was based on mean intake for similar aged children from a U.S. national survey. Individual energy needs were estimated using the Dietary Reference Intake equations. RESULTS: There were independent effects of children's liking ratings and food ED, which did not interact to influence portion selection (p = 0.21). Across all foods, food liking had a strong effect on the portion size selected (p < 0.0001); the magnitude of this effect depended on age (−0.04 ± 0.02; p = 0.015). Food energy density had a smaller effect (p = 0.04) that also depended on age (−0.39 ± 0.15; p = 0.010). Younger children selected larger portions (relative to the reference portion) from higher-ED foods than lower-ED foods; conversely, older children selected smaller portions from higher-ED foods. The effects of age remained significant when adjusted for individual energy needs. The effects on portion selection of either food liking or energy density were not influenced by children's sex, BMI-for-age percentile or BMI z-score. CONCLUSIONS: These results confirm that food liking and food ED are significant determinants of portion selection in children. The finding that liking affected portion selection even for low-ED foods has implications for promoting healthy eating habits in children. Serving larger portions of well-liked low-ED foods such as fruits and vegetables can be a strategy to promote children's intake. FUNDING SOURCES: NCRR, NCATS, NIDDK.