Effects of portion size and energy density on young children's intake at a meal

Abstract

Background: Large portions of energy-dense foods are one feature of obesity-promoting dietary environments. Entrée portion size has been shown to influence energy intake at meals by young children. The role of energy density (ED) in children's response to portion size, however, is unknown.

Objective: We aimed to test the effects of portion size and ED on children's food and energy intakes at a meal.

Design: Participants were 53 (28 girls and 25 boys; 15 Hispanic, 20 black, 16 white, 2 other race) 5- to 6-y-old children [mean (+/-SD) body mass index percentile: = 61 +/- 28]. A 2 x 2 within-subjects design was used to manipulate entrée portion size (250 compared with 500 g) and ED (1.3 compared with 1.8 kcal/g). Fixed portions of other familiar foods were provided. Weighed intake, food preference, and weight and height data were obtained.

Results: Effects of portion size (P<0.0001) and ED (P<0.0001) on entrée energy intake were independent but additive. Energy intake from other foods at the meal did not vary across conditions. Compared with the reference portion size and ED condition, children consumed 76% more energy from the entrée and 34% more energy at the meal when served the larger, more energy-dense entrée. Effects did not vary by sex, age, entrée preference, or body mass index z score.

Conclusions: These findings provide new evidence that portion size and ED act additively to promote energy intake at meals among preschool-aged children.

FIGURE 1

Effects of portion size and energy density (ED) on food intake. Ref, reference; Lg, large. ANOVA was used to test the effects of portion size and ED on food intake, adjusted for child's age, sex, ethnicity, BMI z score, entrée preference, and eating ≥95% of the reference portions (n = 53). Data are presented as LS means (±SEMs); different letters signify mean differences, P < 0.01. Main effects of portion size on entrée intake in grams (F = 21.25, P < 0.0001) and total grams consumed at the meal (F = 9.04, P < 0.01) were observed. Portion size did not affect gram intake of other foods (F = 0.32, P = 0.57). ED did not affect gram intake of the entrée (F = 0.00, P = 0.97), other foods (F = 0.01, P = 0.91), or the total grams consumed at the meal (F = 0.00, P = 0.95). Portion size effects on food intake did not interact with ED.

FIGURE 2

Effects of portion size and energy density (ED) on energy intake. Ref, reference; Lg, large. ANOVA was used to test the effects of portion size and ED on energy intake, adjusted for child's age, sex, ethnicity, BMI z score, entrée preference, and eating ≥ 95% of the reference portions (n = 53). Data are presented as LS means (±SEMs); different letters signify mean differences, P < 0.01. Main effects of portion size on entrée energy intake (F = 19.87, P < 0.0001) and total meal energy (F = 13.34, P < 0.001) were observed. Main effects of ED on entrée energy intake (F = 19.79, P < 0.0001) and total meal energy (F = 19.07, P < 0.0001) were observed. Neither portion size (F = 1.55, P = 0.21) nor ED (F = 0.01, P = 0.92) affected the energy intake of other foods. Portion size effects on energy intake did not interact with ED.