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 biodiversity 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 consumed, 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 micronutrients in the wet season. Compared with Simpson’s index of diversity and functional diversity, species richness (SR) showed stronger associations and better diagnostic properties with micronutrient adequacy. For every additional species consumed, dietary nutrient adequacy increased by 0.03 (P < 0.001). Diets with higher nutrient adequacy were mostly obtained when both SR and DDS were maximal. Adding SR to the minimum cutoff for minimum diet diversity improved the ability to detect diets with higher micronutrient adequacy in women but not in children. Dietary SR is recommended as the most appropriate measure of food biodiversity in diets. Significance Current research linking biodiversity and human diets has used metrics without justification from a nutritional point of view. Diet species richness, or a count of the number of different species consumed per day, assesses both nutritional adequacy and food biodiversity of diets for women and children in rural areas. The positive association of food species richness with dietary quality was observed in both the wet and the dry season. Food biodiversity contributes to diet quality in vulnerable populations in areas with high biodiversity. Reporting the number of species consumed during dietary assessment provides a unique opportunity to cut across two critical dimensions of sustainable development—human and environmental health—and complements existing indicators for healthy and sustainable diets.

Background: Ankober District has long been inhabited by people who have a long tradition of using medicinal plants to treat human ailments. Overexploitation of medicinal plants coupled with an ever-increasing population growth, deforestation and agricultural land expansion threatens plants in the area. Hence, this study aimed at documenting and analyzing the plant-based ethnomedicinal knowledge of the people in order to preserve the dwindling indigenous knowledge. Methods: Ethnobotanical data were collected using semi-structured interviews, focus group discussions, participant observation and walk-in-the-woods. Quantitative approaches were used to determine Informant Consensus Factor (ICF) and Fidelity level (FL) values. Statistical tests were used to compare the indigenous knowledge on medicinal plants among different informant categories. Results: A total of 135 medicinal plant species belonging to 128 genera and 71 botanical families were reported to treat human diseases in the District. Families Asteraceae (12 species, 9%) and Fabaceae (10, 7.4%) were found to be best represented in the area. About 44% of preparations were reported to be obtained from roots. Significant difference (P < 0.05) was observed on the mean number of medicinal plants reported by groups of respondents compared within age, literacy level and experience parameters. Highest ICF values were recorded for gastro-intestinal & parasitic and dermatological disease categories (0.70 each) indicating best agreement among informants knowledge on medicinal plants used to treat aliments in these categories. Highest fidelity level values were recorded for Zehneria scabra (95%) and Hagenia abyssinica (93.75%) showing conformity of knowledge on species of best healing potential. Podocarpus falcatus was ranked first in a direct matrix ranking exercise of multipurpose medicinal plants. The output of preference ranking exercise indicated that Olea europaea subsp. cuspidata was the most preferred species to treat atopic eczema. Conclusion: The study revealed that Ankober District is rich in medicinal plant diversity and associated indigenous knowledge. However, anthropogenic factors coupled with acculturation and very poor conservation efforts threaten medicinal plant survival in the area. Promoting a complementary in situ and ex situ conservation strategy for medicinal plants of the District is highly recommended.