The consumption of larger food portion size(s) (PS) can result in overconsumption and a reduced ability to self-regulate appetite, which has been implicated in the rising prevalence of childhood obesity globally(1). Larger PS of food have sustained effects on energy intake in children(2–4), which has been attributed to the ‘portion size effect’, where more food is consumed when larger quantities are offered(4). This study aimed to explore 3 different PS of a breakfast meal on consumption and satiety levels of children aged 7-10 years.

Parents with their children (n 25) were invited to participate in a within-subject, repeated measures, randomised cross-over study, to compare the PS of a typically consumed breakfast meal (ready-to-eat breakfast cereal [flakes, puffed rice or hoops] with milk) consumed by children under three different PS conditions: self-serve (SS) of typical PS; <25% than SS, and; >25% than SS, with at least 3 days between each experimental PS condition. The children were provided with a 10cm visual analogue scale to rate satiety post-consumption. Repeated measures ANOVA was used to assess differences between the PS consumed and satiety ratings, with paired samples ttests used to compare differences between PS conditions.

Total PS of the breakfast meal consumed was greatest in the SS condition, followed by the >25% than SS with the least PS consumed in the <25% than SS (165.0 ± 72.0g, 138.2 ± 83.3g and 126.0 ± 77.9g respectively, p = 0.011). A significantly higher proportion of the breakfast meal was also consumed in the SS condition compared to both manipulated conditions - SS vs <25% than SS (84.2 ± 19.9% vs 77.2 ± 24.7%, p = 0.030), SS vs >25% than SS (84.2 ± 19.9% vs68.9 ± 28.9%, p<0.001), with a significantly higher proportion consumed in the <25% vs >25% than SS

(77.2 ± 24.7% vs 68.9 ± 28.9%, p = 0.027). Post-consumption, children reported feeling ‘least satisfied’ in the SS condition compared to both other conditions (6.2 ± 2.5cm in SS, 7.5 ± 2.1cm in <25% than SS condition, 7.9 ± 2.1cm in the >25% than SS condition, p = 0.011).

In this exploratory study, children aged 7 to 10 years did not consume a larger amount of food in response to exposure to larger PS. Results suggest that the presentation of smaller PS resulted in higher satiety ratings post-consumption, highlighting the potential of downsizing as a strategy for portion control in children of this age, where needed.