Dietary species richness as a measure of food biodiversity and nutritional quality of diets

Abstract

Biodiversity is key for human and environmental health. Available dietary and ecological indicators are not designed to assess the intricate relationship between food biodiversity and diet quality. We applied biodiversity indicators to dietary intake data from and assessed associations with diet quality of women and young children. Data from 24-hour diet recalls (55% in the wet season) of n = 6,226 participants (34% women) in rural areas from seven low and middle-income countries were analyzed. Mean adequacies of vitamin A, vitamin C, folate, calcium, iron, and zinc and diet diversity score (DDS) were used to assess diet quality. Associations of bio diversity indicators with nutrient adequacy were quantified using multilevel models, receiver operating characteristic curves, and test sensitivity and specificity. A total of 234 different species were con sumed, of which <30% were consumed in more than one country. Nine species were consumed in all countries and provided, on average, 61% of total energy intake and a significant contribution of micro nutrients in the wet season. Compared with Simpson’s index of di versity and functional diversity, species richness (SR) showed stronger associations and better diagnostic properties with micronutrient ad equacy. For every additional species consumed, dietary nutrient ade quacy increased by 0.03 (P < 0.001). Diets with higher nutrient adequacy were mostly obtained when both SR and DDS were max imal. Adding SR to the minimum cutoff for minimum diet diversity improved the ability to detect diets with higher micronutrient ade quacy in women but not in children. Dietary SR is recommended as the most appropriate measure of food biodiversity in diets.