LAUSR

The affordability of healthy diets is a key concern for policymakers and an active area of research. To the best of our knowledge, ours is the first study to examine the cost of nutritionally adequate diets for all population age and sex subgroups at subnational disaggregation over a 10-year monthly time series as well as to extend the least-cost diet framework from individuals to household units who consume shared meals. We use household survey panel data matched with local food composition data, human nutrient requirements (EARs, ULs and AMDRs), and monthly market food prices. The food price data include a standardized list of 51 items comprising those foods accounting for the vast majority of household food spending, covering all food groups. Household data are from the Integrated Household Panel Survey (IHPS) 3-round panel (2010–2017). Using linear programming, we identify the combination of available foods and quantities that meet the specified nutrient requirements at the lowest total cost. Local markets can supply an adequate diet most of the time for some groups but much less often for breastfeeding women and young children, and not at al for children 6–36 months. Where possible, we find that the least-cost individual diet costs 32% of current per capita food spending. For whole households, the local market can meet aggregate nutrient needs 30% of the time. Where possible, it costs 1.8 times household food spending or all total expenditure. Food group analysis reveals households spend more on cereals, meat and roots/tubers, compared to the least-cost adequate diet, but may be under-spending on legumes, milk, fats, and vitamin A-rich fruits. Finding a healthy diet in Malawi's local markets is not always possible for all types of individuals or families of varying composition. Children 6–36 months require immediate attention, including increasing access to complete complementary foods. Guiding households to make smart shifts in their food spending could improve diet quality but is insufficient alone given that adequate shared meals are unaffordable for most families. Year-round access to nutritious, affordable diets will require an increase in availability and lower cost of nutrient-dense foods and economic growth to raise incomes. Bill & Melinda Gates Foundation, CANDASA project.