Global Variation in the Cost of a Nutrient Adequate Diet by Population Group

Abstract

Background: Nutrient deficiencies limit human development, and could be caused by the high cost of locally available foods needed to meet nutrient requirements. In this study, we identify the populations whose nutrient needs are most difficult to meet with existing global food systems. Methods: Using the most recent collection of global food prices (ICP 2017), we compute least-cost diets within upper and lower bounds for energy and 20 nutrients for healthy population across 20 demographic groups in 172 countries. Findings: Diet costs per day have a global median of $2.30 (IQR: 1.95-2.75) in 2017, and are highest for males 14-18 y/o at $2.85 [95%CI: 2.83, 2.88]. For females, cost per day is highest during pregnancy and lactation, exceeding cost for adult males 19-50 y/o. Energy-adjusted costs per 1,000 kcal have a global median of $0.94 (IQR: 0.79-1.12), and are higher for females throughout the life course, peaking for adolescent girls 9-13 y/o and women above 70 y/o at $1.17 [95% CI: 1.15, 1.19] and $1.18 [95% CI: 1.17, 1.19]. Meeting needs at least cost uses more animal-source foods in higher income countries, and more plant-source foods in lower income countries. Diet costs are most sensitive to requirements for calcium, iron, zinc and vitamins C and E, and upper bounds on carbohydrates and sodium. Interpretation: Diets with adequate nutrients are unaffordable for many demographic groups, especially women. Results can help guide agriculture and food policy or transfer programs to support populations at risk of inadequate intake. Funding Statement: UKAid and the Bill & Melinda Gates Foundation Declaration of Interests: The authors declare no competing interests.