The GDD is a collaborative effort to systematically identify, compile and standardize individual-level dietary data on 53 foods, beverages and nutrients (Methods). The GDD uses Bayesian modelling methods to estimate dietary intakes jointly stratified by age, sex, education, level and urbanicity for 185 countries between 1990 and 2018.
Global and regional diet quality in 2018
In 2018, the global mean of the AHEI score was 40.3 (95% uncertainty interval (UI) 39.4, 41.3), with regional means ranging from 30.3 (28.7, 32.2) in Latin America and the Caribbean to 45.7 (43.8, 49.3) in South Asia (Fig. 1). Among components of the score, highest global scores for healthier items were for legumes/nuts (5.0; 4.8, 5.3), followed by whole grains (4.7; 4.5, 5.0), seafood omega-3 fat (4.2; 3.8, 5.1) and non-starchy vegetables (3.9; 3.8, 4.0); among unhealthier items, highest scores (lowest or most favourable intakes) were for sugar-sweetened beverages (SSBs) (5.8; 5.7, 5.9) and red/processed meat (4.8; 4.5, 5.1). However, these score components varied substantially by world region. For example, top scores in South Asia were for higher whole grains and lower red/processed meat and SSBs, while top scores in Latin American and the Caribbean were for higher legumes/nuts and lower sodium.
AHEI score: nine components scored from 0 to 10 each and scaled to ten components (correction for trans fat shown). Healthy components: fruit, non-starchy vegetables, legumes/nuts, whole grains, PUFAs and seafood omega-3 fat; unhealthy components: red/processed meat, SSBs and sodium.
National diet quality in 2018
Only ten countries, representing <1% of the world’s population, had AHEI scores ≥50. Among the world’s 25 most populous countries, the mean AHEI score was highest in Vietnam, Iran, Indonesia and India (54.5 to 48.2) and lowest in Brazil, Mexico, the United States and Egypt (27.1–33.5) (Fig. 2). Most component scores varied substantially across these populous countries. For example, a 100-fold difference was seen in the sodium score, a 90-fold difference in the red/processed meat score and a 23-fold difference in the SSB score. Among the components, the polyunsaturated fatty acid (PUFA) and non-starchy vegetable scores varied the least (two-fold and three-fold, respectively) across populous countries.
Children: ≤1 years to ≤19 years; adults: ≥20 years. The AHEI score ranged from 0 to 100. The mean national score was computed as the sum of the stratum-level component scores and aggregated to the national mean using weighted population proportions for 2018.
Global and regional differences across demographic subgroups
Globally, the mean AHEI score in 2018 was similar among children (39.2; 38.2, 40.3) versus adults (40.8; 39.8, 42.0) (Fig. 1). However, the mean AHEI score was substantially higher among adults compared with children in Central/Eastern Europe and Central Asia, high-income countries, and the Middle East and Northern Africa region. By age, most regions had J- or U-shaped relationships, with the highest scores observed among the youngest (≤5 years) and/or oldest age groups (≥75 years) (Fig. 3).
The AHEI score ranged from 0 to 100. The circles represent the global or regional mean for the age group, and the error bars represent the corresponding 95% UI. The mean and its UI are plotted for the midpoint of each age group (<1, 1–2, 3–4, 5–9, 10–14, 15–19, 20–24, 25–29, 30–34, 35–39, 40–44, 45–49, 50–54, 55–59, 60–64, 65–69, 70–74, 75–79, 80–84, 85–89, 90–94 and ≥95 years).
Among the AHEI components globally, four component scores were lower among children versus adults: fruit (2.2 (2.1, 2.3) versus 2.5 (2.4, 2.5), respectively), non-starchy vegetables (3.1 (3.0, 4.5) versus 4.3 (4.2, 3.2)), SSBs (5.3 (5.1, 5.5) versus 6.1 (6.0, 6.2)) and seafood omega-3 (3.3 (2.9, 4.0) versus 4.7 (4.2, 5.7)), while two others were higher among children versus adults: PUFAs (2.1 (2.0, 2.2) versus 1.4 (1.3, 1.5)) and sodium (4.6 (4.1, 5.1) versus 3.2 (2.9, 3.5)) (Fig. 1).
By sex, the mean AHEI score was generally higher in women versus men globally and regionally, with the greatest differences seen in high-income countries (difference +4.4; 3.8, 5.0), and Central/Eastern Europe and Central Asia (+3.6; 2.1, 5.3) (Extended Data Fig. 1). Evaluating different AHEI components globally, women had modestly higher scores for fruit (+0.2; 0.2, 0.3), non-starchy vegetables (+0.3; 0.1, 0.4) and whole grains (+0.4; 0.2, 0.5).
Evaluating differences according to educational attainment, AHEI scores were greater among individuals with a higher education level globally and in most regions, except in the Middle East and Northern Africa and Sub-Saharan Africa, where no differences were evident (Fig. 4). Among world regions, differences by education were largest in Central/Eastern Europe and Central Asia (+3.6; 2.4, 4.9), Latin America and the Caribbean (+3.5; 0.9, 6.0) and South Asia (+2.9; 1.1, 4.9). Globally, more educated individuals had higher scores for fruit (+0.8; 0.7, 0.9), sodium (+0.7; 0.3, 1.1), whole grains (+0.6; 0.4, 0.8) and non-starchy vegetables (+0.5; 0.4, 0.6). However, in contrast, more educated individuals also had lower scores (less favourable consumption levels) for red/processed meat (−0.6; −0.7, −0.5), SSBs (−0.6; −0.8, −0.4) and nuts and legumes (−0.1; −0.2, −0.1) globally.
AHEI score: nine components scored from 0 to 10 each and scaled to ten components (correction not shown). The absolute difference by education was computed as the difference at the stratum level and aggregated to the global and regional mean differences using weighted population proportions for low (<6 years) and high education levels (≥12 years) only (excludes education level ≥6 and <12 years).
Globally, AHEI scores did not significantly vary by urban versus rural residence (Fig. 5). However, higher scores were evident among urban versus rural individuals in Central/Eastern Europe and Central Asia (difference +2.2; 0.9, 3.5), and Southeast and East Asia (+1.4; 0.6, 2.4), and lower scores among urban versus rural individuals in the Middle East and Northern Africa (−3.8; −5.5, −2.2). Globally, individuals residing in urban areas had higher scores for fruit (+0.2; 0.2, 0.3) and whole grains (+0.2; 0.1, 0.4), but lower scores for SSBs (−0.5; −0.7, −0.4), red/processed meat (−0.4, −0.5, −0.1) and legumes/nuts (−0.1; −0.2, −0.1).
AHEI score: nine components scored from 0 to 10 each and scaled to ten components (correction not shown). The absolute difference by urbanicity was computed as the difference at the stratum level and aggregated to the global and regional mean differences using weighted population proportions.
Changes in dietary pattern scores between 1990 and 2018
Between 1990 and 2018, the mean global AHEI score (standardized to 2018 population distributions) increased by +1.5 (1.0, 2.0). Increasing trends occurred in five of seven regions: Central/Eastern Europe and Central Asia (+4.6; 4.0, 5.3); high-income countries (+3.2; 2.9, 3.5); Southeast and East Asia (+2.7; 1.7, 3.8); the Middle East and Northern Africa (+2.2; 1.4, 3.0); and Latin America and the Caribbean (+1.3; 0.6, 2.0). No significant change was seen in South Asia (0; −0.9, 1.1), and a decreasing trend was seen in Sub-Saharan Africa (−1.1; −1.8, −0.4) (Fig. 6).
AHEI score: nine components scored from 0 to 10 each and scaled to ten components (correction not shown). The absolute difference by time was computed as the difference at the stratum level and aggregated to the global and regional mean differences using weighted population proportions for 2018.
Among AHEI components globally, scores increased over time for non-starchy vegetables (+1.1; 1.0, 1.2), legumes/nuts (+1.1; 1.0, 1.3) and fruit (+0.1; 0.1, 0.2); decreased for red/processed meat (−1.4; −1.5, −1.2), SSBs (−0.6; −0.7, −0.6) and sodium (−0.4; −0.6, −0.2); and remained stable for whole grains (+0.1; 0, 0.2), PUFAs (0; 0, 0.1) and seafood omega-3 (0; 0, 0.1).
Among the most populous countries, the largest absolute improvement in the AHEI score between 1990 and 2018 occurred in Iran (+12.0; 9.9, 13.9), the United States (+4.6; 4.1, 5.1), Vietnam (+4.5; 2.4, 7.2) and China (+4.3; 2.8, 5.9), while the largest declines were found in Tanzania (−3.7; −5.8, −1.5), Nigeria (−3.0; −5.3, −0.7), Japan (−2.7; −3.1, −2.3) and the Philippines (−1.8; −2.7, −0.9) (Fig. 7).
The AHEI score ranged from 0 to 100. The absolute difference between 2018 and 1990 was computed as the difference at the stratum level and aggregated to the national mean differences using weighted population proportions for 2018.
Results for DASH and MED
Detailed findings for the DASH and MED scores are presented in Supplementary Information. Briefly, global mean DASH and MED scores in 2018 were 22.9 (22.6, 23.2) and 4.1 (3.9, 4.2), respectively (Extended Data Figs. 2 and 3). Regionally, means for these scores were consistently higher in South Asia, and lower in Latin America and the Caribbean (Extended Data Figs. 4 and 5). Among population subgroups, global DASH and MED scores were higher among adults compared with children (DASH: 23.2 (22.9, 23.4) versus 22.3 (21.9, 22.7); MED: 4.3 (4.1, 4.4) versus 3.7 (3.5, 3.8)), but did not appreciably differ by sex (Extended Data Figs. 2 and 3). Global mean scores were higher among more versus less educated individuals (difference +2.6 (2.3, 2.8) and +0.3 (0.2, 0.4), respectively) (Extended Data Fig. 7), and, for DASH only, among urban versus rural individuals (+0.4; 0.2, 0.7) (Extended Data Fig. 8). Worldwide, the mean DASH and MED scores increased modestly between 1990 and 2018, by +1.0 (0.8, 1.1) for DASH and +0.3 (0.2, 0.4) for MED (Extended Data Figs. 6 and 9). Across strata in 2018, the inter-correlations of the dietary pattern scores were 0.8 for AHEI and DASH, 0.5 for AHEI and MED, and 0.6 for DASH and MED.