Does Milk Portion Size or Energy Density Affect Preschool Children's Lunch Intake?

Abstract

Government‐sponsored programs, such as the Child and Adult Care Food Program, recommend serving age‐appropriate portions of lower‐energy‐dense milk in order to moderate energy intake while promoting a nutrient‐dense diet. It is unclear, however, to what extent changes in milk portion size and energy density (ED) affect children's intake of both milk and the accompanying foods. To evaluate these recommendations, controlled studies are needed to determine if these factors influence children's intake of a meal served in their usual eating environment. Using a 2‐by‐2 crossover design, we investigated the influence of typical variations in milk portion size and ED on intake when milk was served with a standard lunch. Experimental meals were served once a week for 4 weeks in childcare classrooms and was consumed ad libitum by 125 children aged 3–5 y (67 boys and 58 girls). Across the 4 meals, unflavored milk was varied in portion size (9 fl. oz. or 6 fl.oz. [recommended]) and ED (3.25% full‐fat [0.61 kcal/g] or 1% low‐fat [0.42 kcal/g; recommended]). The foods served at the meal (chicken, pasta, broccoli, and bananas) were not varied. The results showed that serving the larger portion of milk increased milk energy intake by 20±3 kcal (27%; P<0.0001) compared to serving the smaller portion, but had no significant effect on food intake or meal energy intake. Serving higher‐ED milk increased milk energy intake by 31±2 kcal (44%) and decreased food energy intake by 26±6 kcal (10%) compared to serving lower‐ED milk (both P<0.0001). Thus, across all children, the change in milk ED did not influence total energy intake at the meal. The effects of milk portion size and ED were not influenced by most child characteristics, such as age, body size, and parent‐reported eating behaviors; however, the effect of milk ED on intake did differ significantly by sex. For boys, serving higher‐ED milk decreased food energy intake by 43±8 kcal (16%; P<0.0001) and did not affect total energy intake compared to serving lower‐ED milk. For girls, consuming more energy from the higher‐ED milk did not lead to a significant compensatory reduction in food energy intake and an additional 24±10 kcal (7%; P=0.03) was consumed over the entire meal. This suggests that boys, but not girls, adjusted their food energy intake in response to changes in ED of milk consumed with lunch. These results showed that serving larger portions of milk could promote milk intake without affecting total energy intake at a meal. However, the provision of lower‐ED milk is appropriate for preschool nutrition programs, since some children did not fully adjust their intake in response to higher‐ED milk and increased their lunch energy intake.Support or Funding InformationUSDA NIFA Grant 2011‐67001‐30117 and National Institutes of Health Grant DK082580.