Low-burden metrics for monitoring healthy diets among nonpregnant females aged 15 to 49 years: a multicountry validation analysis using quantitative 24-hour dietary intake data.
BACKGROUND: Limited nationally representative quantitative dietary intake data and a lack of consensus on lower-burden tools and metrics hinder high-frequency monitoring of healthy diets globally. OBJECTIVES: This study aimed to evaluate the comparative construct validity and potential complementarity of low-burden metrics of a healthy diet among nonpregnant females aged 15 to 49 y. METHODS: Quantitative 24-h dietary intake data collected from 77,118 adolescent and adult females across 27 countries were used to construct low-burden metrics and reference metrics of dietary intake. Associations between mean-standardized low-burden measures or indicators and reference metrics were assessed using linear and logistic mixed-effect models, with Spearman's ρ used for survey-level rank correlations. Test characteristics identified low-burden indicators best differentiated adherence to reference indicators. RESULTS: An indicator reflecting nonconsumption of sweet foods and/or sweet beverages was most robustly associated with greater adherence to <10% energy from free sugars in upper-middle-income countries {odds ratio [OR] [95% confidence interval (CI)]: 5.35 [5.05, 5.66]}. Food group diversity score (FGDS) was most strongly associated with and differentiated higher mean adequacy ratio of micronutrients [β of 1-standard deviation (SD) change: ∼11 percentage points (9, 12); ρ: 0.79], whereas noncommunicable disease-Protect score best reflected consumption of ≥400 g/d of fruits and vegetables [range OR of 1-SD changes (95% CI): 2.56-3.01 (2.40, 3.13) in lower-middle and high-income countries, respectively; ρ: 0.56]. FGDS and Global Diet Quality Score Positive were most consistently associated with achieving ≥25 g/d of fiber and ≥3510 mg/d of potassium across contexts. CONCLUSIONS: Low-burden data collection tools yield valid metrics, enabling high-frequency monitoring of healthy diets across contexts. Specifically, avoiding sweet foods and/or sweet beverages is an indicator for adherence to WHO free sugar guidelines among nonpregnant females in upper-middle-income countries, whereas metrics reflecting nutritious food group diversity strongly reflect better micronutrient adequacy and adherence to WHO guidelines for fruits and vegetables, fiber, and potassium intakes within and across contexts.