Quantification of regional variation in ultra-processed food consumption and its sociodemographic correlates across Bangladesh, India, Pakistan, and Sri Lanka: insights from the South Asia Biobank.

Background: Sales of ultra-processed foods (UPFs) are rising in South Asia, yet UPF consumption and its sociodemographic determinants remain largely unknown. We aimed to quantify UPF consumption and investigate its sociodemographic correlates in four countries of South Asia. Methods: Between January 2020 and September 2022, the South Asia Biobank recruited 63,914 participants aged 18 years or older who were resident in Bangladesh, Pakistan, Sri Lanka, and North and South India, and self-reported as being of South Asian ethnicity. We analysed data from 60,714 eligible adults. Dietary consumption was assessed using interviewer-led 24-h recalls. Foods were classified by their degree of processing using the NOVA classification. Two-part multivariable-adjusted regression models examined associations of sociodemographic factors with the likelihood and quantity of UPF consumption. Findings: In Bangladesh, Sri Lanka, and North India, ∼75% of participants reported consuming UPFs during the previous day, versus 41% in South India and Pakistan. Among consumers, UPFs contributed 13-17% of total energy intake, with biscuits being a common source across regions. Other UPFs included sweetened beverages in Pakistan, packaged salty snacks in South India, and breakfast cereals in Bangladesh. Younger age was associated with UPF consumption in Pakistan and Sri Lanka whereas in Bangladesh and North India, older age was. Women were more likely to consume UPFs in all regions except Bangladesh. In Bangladesh, Pakistan, and North India, any level of education above none (i.e., primary, secondary, or higher) was associated with UPF consumption. Among consumers, UPF consumption was lower in married or cohabiting than single people, in all regions. UPF consumption was higher in rural versus urban residents in Bangladesh and Sri Lanka but lower in Pakistan. Interpretation: UPF consumption varied across South Asia by sociodemographic factors including age, gender, and education. Understanding this heterogeneity is crucial when designing interventions aimed at reducing UPF consumption. Our findings of regional variations in the types of UPFs consumed provide valuable insights for targeted interventions. Funding: The South Asia Biobank is funded by the National Institute for Health Research.