RESUMEN
Large portion sizes of food can lead to excessive energy intake and weight gain in young children. Although portion size guidance is available, parents are often unaware it exists. Our systematic grey literature review aimed to identify the portion size guidance resources in the United Kingdom and Ireland, aimed at users (e.g., parents and childcare providers) responsible for feeding preschool-aged children. We describe who the resources are aimed at, how they are informed and whether the recommended portion sizes are consistent across resources. Resources were identified via advanced Google searches, searching reference lists and contacting experts. Resources that provided quantifiable portion size information (e.g., grammes) were included. Portion sizes (g) were extracted and energy equivalents (kcal) were calculated. Portion sizes were analysed by food group and by eating occasion. Twenty-two resources were identified. Median portion sizes were consistent across resources for fruit (40 g [IQR = 40-50]) and vegetables (40 g [IQR = 30-40]). Variability was observed in portion size and/or energy content for dairy (60 g [IQR = 25-93]), protein (72 kcal [IQR = 44-106]) and starchy (41 g/71 kcal [IQR = 25-80/56-106]) food groups. The range in size of an average eating occasion was large (90-292 g). This review identifies resources that could help caregivers to choose appropriate portion sizes for preschool-aged children but also highlights how future resources could be improved.