Abstract
INTRODUCTION: Diet is a major modifiable risk factor for cardiometabolic disease; however, interpretable measures capturing impacts of overall diet on health that can be easily used by policymakers at the global/national levels are not readily available. METHODS: We developed the International Diet-Health Index (IDHI) to measure health impacts of dietary intake across 186 countries in 2010, using age-specific and sex-specific data on country-level dietary intake, effects of dietary factors on cardiometabolic diseases and country-specific cardiometabolic disease profiles. The index encompasses the impact of 11 foods/nutrients on 12 cardiometabolic diseases, the mediation of health effects of specific dietary intakes through blood pressure and body mass index and background disease prevalence in each country-age-sex group. We decomposed the index into IDHI(beneficial) for risk-reducing factors, and IDHI(adverse) for risk-increasing factors. The flexible functional form of the IDHI allows inclusion of additional risk factors and diseases as data become available. RESULTS: By sex, women experienced smaller detrimental cardiometabolic effects of diet than men: (females IDHI(adverse) range: -0.480 (5th percentile, 95th percentile: -0.932, -0.300) to -0.314 (-0.543, -0.213); males IDHI(adverse) range: (-0.617 (-1.054, -0.384) to -0.346 (-0.624, -0.222)). By age, middle-aged adults had highest IDHI(beneficial) (females: 0.392 (0.235, 0.763); males: 0.415 (0.243, 0.949)) and younger adults had most extreme IDHI(adverse) (females: -0.480 (-0.932, -0.300); males: -0.617 (-1.054, -0.384)). Regionally, Central Latin America had the lowest IDHI(overall) (-0.466 (-0.892, -0.159)), while Southeast Asia had the highest IDHI(overall) (0.272 (-0.224, 0.903)). IDHI(overall) was highest in low-income countries and lowest in upper middle-income countries (-0.039 (-0.317, 0.227) and -0.146 (-0.605, 0.303), respectively). Among 186 countries, Honduras had lowest IDHI(overall) (-0.721 (-0.916, -0.207)), while Malaysia had highest IDHI(overall) (0.904 (0.435, 1.190)). CONCLUSION: IDHI encompasses dietary intakes, health effects and country disease profiles into a single index, allowing policymakers a useful means of assessing/comparing health impacts of diet quality between populations.