Minimum Dietary Diversity for Adolescents: Multicountry Analysis to Define Food Group Thresholds Predicting Micronutrient Adequacy among Girls and Boys Aged 10-19 Years

Background: Adolescents' diets have been overlooked in nutrition information systems, interventions, and policies. The minimum dietary diversity for women (MDD-W) indicator has been validated to signal greater micronutrient adequacy among nonpregnant women from lowand middle-income countries, but there is limited evidence for valid food group thresholds among boys or nonpregnant nonlactating girls. Objective: To define a food group threshold that reflects minimum dietary diversity for adolescents. Methods: This multicountry study evaluated the test characteristics of a 10 -point food group diversity score (FGDS)-underlying MDD-W-and food group thresholds to predict the micronutrient adequacy of diets from single 24-h recalls or food diaries (24-HRs) among 83,935 adolescents aged 10-19 y and repeated 24-HRs among 75,480 adolescents from upper-middle and high-income countries. Results: FGDS was lowest among adolescents in lower-middle countries (3.5 +/- 1.1) and greatest in high-income countries (5.4 +/- 1.3 points). Using single 24-HRs, 1 -point increments in FGDS performed identically to predict a higher mean adequacy ratio among boys and girls (5.1 percentage points; 95% confidence interval: 5.0, 5.2; P < 0.001). MDD-W (i.e., >= 5 food groups) performed well in predicting a mean adequacy ratio of >0.60 among adolescents from upper-middle and high-income countries, whereas a >= 4 food group cutoff showed a superior balance between sensitivity, specificity, and percentage correctly classified in low (only girls) and lower-middle-income countries (boys and girls). In contrast, using repeated 24-HRs, the mean probability of adequacy levels among adolescents were too high and homogeneous (i.e., all mean probability of adequacies > 0.60) to define an optimal food group threshold. Conclusions: MDD-W can be extended to boys and girls aged 10-19 y from upper-middle and high-income countries. Furthermore, an adapted indicator using a >= 4 food group threshold signals higher micronutrient adequacy in low and lower-middle-income countries. Food group cutoffs to predict the micronutrient adequacy of usual intakes should be validated using repeated 24-HRs in populations where a lower proportion of adolescents meet mean dietary requirements.