Jessica Raneri

Assessing the Potential of Wild Foods to Reduce the Cost of a Nutritionally Adequate Diet: An Example from Eastern Baringo District, Kenya

Background Wild foods and their actual and potential contributions to nutrition security have rarely been studied or considered in nutrition and conservation programs. Objective To study the role of wild food biodiversity in achieving a cost reduction of a nutritionally adequate diet for women and young children in Kenya using linear programming. Methods An ethnobiological inventory of available food biodiversity was carried out by means of focus group discussions, and five wild foods were selected for further modeling. A market survey assessed available food prices by season. Diets were modeled to minimize cost and maximize nutrient adequacy using the Cost of Diet linear programming tool. Modeling was done without and with wild foods. Results The modeled diets without wild species were deficient in iron for all age groups during the dry season, deficient in vitamin B6 and calcium for infants aged 6 to 8 months during the dry season, and deficient in iron and zinc for infants aged 6 to 8 months over the whole year. Adding wild foods, especially Berchemia discolor, to the modeled diets resulted in a lower-cost diet, while meeting recommended iron intakes for women and children between 12 and 23 months of age. Even after integrating wild foods into the model, targeted approaches are needed to meet micronutrient requirements for infants from 6 to 8 and from 9 to 11 months of age. Conclusions An application of linear programming to screen available wild foods for meeting recommended nutrient intakes at a minimal cost was illustrated. This type of study helps to objectively assess the potential of biodiversity to contribute to diets and nutrition.

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

Integrated systems research in nutrition-sensitive landscapes: A theoretical methodological framework

South Asia and sub-Saharan Africa are two regions of the world with the highest concentration of nutritionally vulnerable populations that depend to a large extent on agriculture as an important source of livelihood (Gillespie et al., 2015). The vast majority of farmers in these regions have small landholdings due to land fragmentation (Jayne et al., 2014; Valbuena et al., 2015) and are often constrained in their access to resources and agricultural inputs (Herrero et al., 2010), especially women (e.g., Cole et al., 2015). As a consequence, productivity levels are low, and because income sources are also limited, dependence on surrounding landscapes and ecosystem services is high in terms of safeguarding supplies of clean water, human and animal foods, construction materials and fuel wood. People shape their physical landscapes (Ellis, 2015), influenced by cultures, values and livelihood opportunities (Horlings, 2015). People’s utilization of their physical landscapes is shaped by various conditions such as soil properties, topography, climate and flooding patterns. People’s dependence on their physical landscapes is strong and expected to increase due to climate change, resulting in gradual but persistent changes including adjustments in frequency, timing and severity of anomalies such as droughts and floods (Naylor et al., 2007; Gornall et al., 2010).