Universal Subconstructs of a Healthy Diet for Children and Adolescents: A Critical Review.

To monitor diets among children and adolescents, a thorough understanding of the underlying subconstructs of a healthy diet is needed to inform what should be measured. The aim of this study was to identify universal subconstructs of a healthy diet for children and adolescents aged 2-19 y, understand alignment with subconstructs for adults, and inform recommendations for metrics that aim to monitor the healthiness of diets among children and adolescents at global and national levels. A critical narrative review was carried out in 3 phases. Phase 1: A systematic review of literature published between 2014 and 2024 was conducted. A subset of articles (n = 100) was purposefully sampled based on predefined characteristics. Then, content analysis was performed to identify subconstructs of healthy diets. Phase 2: The identified dietary subconstructs were compared with the 6 subconstructs for adults recognized by the Healthy Diets Monitoring Initiative (HDMI). Phase 3: The identified subconstructs were compared with existing healthy diet metrics concurrently identified by HDMI as suitable for global monitoring of child and adolescent diets. Eight subconstructs specific to children and adolescents were identified: nutrient, energy, and food group requirements; foods and nutrients to limit or avoid; food group diversity and variety; macronutrient and energy balance; nutrient-rich foods or food groups; food safety; eating frequency; and eating regularity. Compared with the 6 subconstructs of adult healthy diets identified by HDMI, 2 subconstructs differed in their operationalization and 2 child- and adolescent-specific subconstructs were considered to be not conceptually distinct. Diet metrics identified as suitable for global monitoring of child and adolescent diets reflect nutrient, energy, and food group requirements; foods and nutrients to limit or avoid; and food group diversity and variety but no other diet subconstructs. The findings inform the development and validation of healthy diet metrics for children and adolescents.