Global, regional, and national tuberculosis burden associated with six suboptimal dietary exposures from 1990 to 2021: a comparative risk assessment based on the Global Burden of Disease Study 2021.

BACKGROUND: Tuberculosis (TB) remains a major public health challenge, and nutritional deprivation continues to shape TB susceptibility, progression, and outcomes. However, the population-level TB burden associated with specific suboptimal dietary exposures has not been systematically quantified across countries, sociodemographic settings, and time. We estimated global, regional, and national TB mortality and disability-adjusted life years (DALYs) associated with six suboptimal dietary exposures from 1990 to 2021 using the Global Burden of Disease (GBD) Study 2021. METHODS: We extracted GBD 2021 estimates of TB deaths, DALYs, age-standardized mortality rates (ASMRs), and age-standardized DALY rates (ASDRs) associated with diets high in processed meat, high in red meat, high in sugar-sweetened beverages, low in fruits, low in vegetables, and low in whole grains across 204 countries and territories. The GBD comparative risk assessment (CRA) framework integrates multisource population, dietary exposure, disease surveillance, vital registration, demographic, and published epidemiological data to estimate modelled population-attributable burden. Rates were calculated using population denominators and expressed per 100,000 persons. Temporal trends were assessed using estimated annual percentage changes (EAPCs). Additionally, we applied age-period-cohort (APC) models to isolate the independent contributions of age, calendar period, and birth cohort to both TB mortality and DALY rates associated with suboptimal dietary exposures. RESULTS: In 2021, diet low in whole grains and diet low in fruits were the two largest contributors to diet-associated TB DALYs, accounting for 177,304 DALYs and 164,027 DALYs, respectively. Smaller absolute burdens were associated with low vegetable intake, high red meat intake, high processed meat intake, and high sugar-sweetened beverage intake. From 1990 to 2021, all six exposures showed declining ASDRs and ASMRs, with ASDR EAPCs ranging from -0.94% for diet high in sugar-sweetened beverages to -2.94% for diet low in vegetables and ASMR EAPCs ranging from -1.33% to -3.24%. Globally, the ASDR of diet high in processed meat decreased from 1.92 [95% uncertainty interval (UI): 0.45 to 3.38] to 0.92 (95% UI: 0.22 to 1.58) per 100,000 persons, and the ASMR decreased from 0.06 (95% UI: 0.01 to 0.11) to 0.03 (95% UI: 0.01 to 0.05) per 100,000 persons. Most exposures showed the highest ASDR and ASMR in low-sociodemographic index (SDI) regions and the lowest in high-SDI regions. Men and older adults had higher DALY and mortality rates across most exposures. APC analyses showed negative net drifts for both DALY and mortality rates across all exposures. CONCLUSIONS: The age-standardized TB burden associated with suboptimal dietary exposures declined globally from 1990 to 2021, but substantial absolute burden and socioeconomic disparities persisted. Population-level nutrition-sensitive strategies, including improved access to whole grains, fruits, and vegetables, nutrition support within TB care, and structural reforms addressing food insecurity and inequities in TB prevention and treatment, may complement biomedical TB control programs, particularly in low-SDI settings.