Cross-context equivalence and agreement of healthy diet metrics for national and global monitoring: a multicountry analysis of cross-sectional quantitative 24-hour dietary intake studies

Composite metrics weighting both healthy and unhealthy food groups have limited cross-context equivalence, because a wide range of diets can theoretically return similar scores. Healthy food group (sub)metrics performed comparably, likely indicating strong underlying construct validity (i.e., dietary diversity and nutrient adequacy). For national and global monitoring, refinement and validation of unhealthy food group metrics (i.e., moderation) is recommended to complement healthy food group metrics.