Conceptual Links between Landscape Diversity and Diet Diversity: A Roadmap for Transdisciplinary Research

Even low levels of tree cover improve dietary quality in West Africa

Forests are attracting attention as a promising avenue to provide nutritious and "free" food without damaging the environment. Yet, we lack knowledge on the extent to which this holds in areas with sparse tree cover, such as in West Africa. This is largely due to the fact that existing methods are poorly designed to quantify tree cover in drylands. In this study, we estimate how various levels of tree cover across West Africa affect children's (aged 12-59 months) consumption of vitamin A-rich foods. We do so by combining detailed tree cover estimates based on PlanetScope imagery (3 m resolution) with Demographic Health Survey data from >15,000 households. We find that the probability of consuming vitamin A-rich foods increases from 0.45 to 0.53 with an increase in tree cover from the median value of 8.8 to 16.8% (which is the tree cover level at which the predicted probability of consuming vitamin A-rich foods is the highest). Moreover, we observe that the effects of tree cover vary across poverty levels and ecoregions. The poor are more likely than the non-poor to consume vitamin A-rich foods at low levels of tree cover in the lowland forest-savanna ecoregions, whereas the difference between poor and non-poor is less pronounced in the Sahel-Sudan. These results highlight the importance of trees and forests in sustainable food system transformation, even in areas with sparse tree cover.

Estimates and trends of zero vegetable or fruit consumption among children aged 6-23 months in 64 countries

Children require a diverse diet, that includes vegetables and fruits, to support growth and development and prevent non-communicable diseases. The WHO-UNICEF established a new infant and young child feeding (IYCF) indicator: zero vegetable or fruit (ZVF) consumption among children aged 6-23 months. We estimated the prevalence, trends, and factors associated with ZVF consumption using nationally representative, cross-sectional data on child health and nutrition in low-and-middle-income countries. We examined 125 Demographic and Health Surveys in 64 countries conducted between 2006-2020 with data on whether a child ate vegetables or fruits the previous day. Prevalence of ZVF consumption was calculated by country, region, and globally. Country trends were estimated and tested for statistical significance (p<0.05). Logistic regression analysis was used to examine the relationship between ZVF and child, mother, household, and survey cluster characteristics by world region and globally. Using a pooled estimate of the most recent survey available in each country, we estimate the global prevalence of ZVF consumption as 45.7%, with the highest prevalence in West and Central Africa (56.1%) and the lowest in Latin America and the Caribbean (34.5%). Recent trends in ZVF consumption varied by country (16 decreasing, eight increasing, 14 no change). Country trends in ZVF consumption represented diverse patterns of food consumption over time and may be affected by the timing of surveys. Children from wealthier households and children of mothers who are employed, more educated, and have access to media were less likely to consume ZVF. We find the prevalence of children aged 6-23 months who do not consume any vegetables or fruits is high and is associated with wealth and characteristics of the mother. Areas for future research include generating evidence from low-and-middle-income countries on effective interventions and translating strategies from other contexts to improve vegetable and fruit consumption among young children.

Wild foods contribute to women's higher dietary diversity in India

Wild foods, from forests and common lands, can contribute to food and nutrition security. Most previous studies have established correlations between wild food consumption and children's dietary diversity in Africa, but other groups and geographic contexts remain understudied. Here a rigorous quasi-experimental method was combined with monthly interval data to assess the contribution of wild foods to women's diets. We collected 24 h diet recall data monthly, from November 2016 to November 2017, from 570 households in East India. We found that wild foods contributed positively to diets, especially in June and July (when consumption of wild foods was highest). Women who consumed wild foods had higher average dietary diversity scores (13% and 9% higher in June and July, respectively) and were more likely to consume nutrient-dense, dark-green leafy vegetables than those who did not. Our results underscore the importance of policies that increase knowledge of wild foods and protect people's rights to access forests and other common lands for improved nutrition.

Un-yielding: Evidence for the agriculture transformation we need

There has been a seismic shift in the center of gravity of scientific writing and thinking about agriculture over the past decades, from a prevailing focus on maximizing yields toward a goal of balancing trade-offs and ensuring the delivery of multiple ecosystem services. Maximizing crop yields often results in a system where most benefits accrue to very few (in the form of profits), alongside irreparable environmental harm to agricultural ecosystems, landscapes, and people. Here, we present evidence that an un-yielding, which we define as de-emphasizing the importance of yields alone, is necessary to achieve the goal of a more Food secure, Agrobiodiverse, Regenerative, Equitable and just (FARE) agriculture. Focusing on yields places the emphasis on one particular outcome of agriculture, which is only an intermediate means to the true endpoint of human well-being. Using yields as a placeholder for this outcome ignores the many other benefits of agriculture that people also care about, like health, livelihoods, and a sense of place. Shifting the emphasis to these multiple benefits rather than merely yields, and to their equitable delivery to all people, we find clear scientific evidence of win-wins for people and nature through four strategies that foster FARE agriculture: reduced disturbance, systems reintegration, diversity, and justice (in the form of securing rights to land and other resources). Through a broad review of the current state of agriculture, desired futures, and the possible pathways to reach them, we argue that while trade-offs between some ecosystem services in agriculture are unavoidable, the same need not be true of the end benefits we desire from them.

Role of Wild Food Environments for Cultural Identity, Food Security, and Dietary Quality in a Rural American State

Wild foods are primary components of traditional and Indigenous food systems that are valued for food security while being vulnerable to global change. This case study examines practices, experiences, and perceptions associated with wild food environments through a household survey in the rural American state of Montana. Findings highlight that wild food environments contribute to cultural identity, sense of place, food security, and dietary quality of surveyed households while being vulnerable to loss of traditional ecological knowledge as well as climate and land-use change. Of the 182 informants, 80% hunt, 83% fish, and 68% forage wild botanicals. More than half of the informants agreed that wild food procurement is part of their cultural identity (66%). Collectively, informants procure more than 172 wild food species with the most prevalent being deer, waterfowl, elk, trout, bass, a range of berries, mushrooms, and botanicals used medicinally. Participants have a multidimensional value system where wild food procurement is valued for diets, recreation, family time, spirituality, and connection to the environment. The majority of participants agreed that the consumption of wild foods contributes to the nutritional quality (87%) and diversity (82%) of their diets while lowering food costs (59%). At least half of the informants reported observing changes in climate patterns over the past decade including increased temperature (50%) and more extreme and variable weather patterns (38%) that they perceive are impacting wild food environments including shifts in wild game, fish, and edible plant populations. Based on findings, we support that wild food environments and associated bio-cultural resources are a critical place to understand, conserve, and promote for nutrition. We thus advance the concept of “conservation for nutrition”. Community engagement, education, and policy plans are called for to promote wild food environments toward supporting sustainable diets and planetary health.

Deforestation reduces fruit and vegetable consumption in rural Tanzania

Two billion people across the planet suffer from nutrient deficiencies. Dietary diversification is key to solving this problem, yet many food and nutrition security policies, especially in low- and middle-income countries, still focus on increasing agricultural production and access to sufficient calories as the main solution. But calories are not all equal. Here, we show how deforestation in Tanzania caused a reduction in fruit and vegetable consumption (of 14 g per person per day) and thus vitamin A adequacy of diets. Using a combination of regression and weighting analyses to generate quasi-experimental quantitative estimates of the impacts of deforestation on people’s food intake, our study establishes a causal link between deforestation and people’s dietary quality.

Strategies to improve food and nutrition security continue to promote increasing food via agricultural intensification. Little (if any) consideration is given to the role of natural landscapes such as forests in meeting nutrition goals, despite a growing body of literature that shows that having access to these landscapes can improve people’s diets, particularly in rural areas of low- and middle-income countries. In this study, we tested whether deforestation over a 5-y period (2008–2013) affected people’s dietary quality in rural Tanzania using a modeling approach that combined two-way fixed-effects regression analysis with covariate balancing generalized propensity score (CBGPS) weighting which allowed for causal inferences to be made. We found that, over the 5 y, deforestation caused a reduction in household fruit and vegetable consumption and thus vitamin A adequacy of diets. The average household member experienced a reduction in fruit and vegetable consumption of 14 g⋅d⁻¹, which represented a substantial proportion (11%) of average daily intake. Conversely, we found that forest fragmentation over the survey period led to an increase in consumption of these foods and dietary vitamin A adequacy. This study finds a causal link between deforestation and people’s dietary quality, and the results have important implications for policy makers given that forests are largely overlooked in strategies to improve nutrition, but offer potential “win–wins” in terms of meeting nutrition goals as well as conservation and environmental goals.

Climate, landscape diversity, and food sovereignty in arid Australia: The firestick farming hypothesis

OBJECTIVE

Climate change has long been recognized as a significant driver of dietary diversity and dietary quality. An often overlooked aspect of climate change are shifts in fire regimes, which have the potential to drastically affect landscape diversity, species distributions, and ultimately, human diets. Here, we investigate whether the fire regimes shaped by Indigenous Australians change landscape diversity in ways that improve dietary quality, considering both the diversity and the quantity of traditional foods in the diet.

METHODS

We use structural equation modeling to explore two causal models of dietary quality, one focused on the direct effects of climate change and resource depression, the other incorporating the dietary effects of landscape diversity, itself a product of fire-created patchiness. We draw on a focal camp dataset covering 10 years of observations of Martu foraging income in the Western Desert of Australia.

RESULTS

We find strong support for the hypothesis that fire-created patchiness improves diet quality. Climate change (cumulative 2-year rainfall) has only an indirect effect on dietary quality; the availability of traditional foods is mediated primarily through the landscape diversity shaped by fire.

CONCLUSIONS

Our model suggests that the loss of the indigenous fire mosaic may lead to worsening availability of traditional foods, measured as both caloric intake and diet diversity. Because the effects of rainfall are mediated through landscape diversity, increased rainfall may not compensate for the recent changes in fire regimes resulting from the loss of Aboriginal fire from the landscape.