The research team, led by Janet Tapkigen of Tampere University together with colleagues from the Kenya Medical Research Institute, King’s College London, and Tampere University, set out to map how the drivers of Nairobi’s food system interact and how different stakeholders experience them. Using the High Level Panel of Experts (HLPE) framework as an analytical scaffold, the researchers conducted focus group discussions, in-depth interviews, and key informant interviews with 42 participants drawn from Nairobi’s major markets, county government sectors, and research institutions. Through deductive and inductive content analysis of the transcripts, they identified fifteen distinct drivers shaping the city’s food system, ranging from climate change and infrastructure to globalisation, social media, and cooking fuel availability.

What makes the findings striking is that climate change did not appear as a single isolated pressure. It cut across nearly every other driver the researchers documented, acting as what the authors describe as a cross-cutting force that amplifies existing weaknesses throughout the supply chain. Heavy rains in food-producing regions such as Garissa cut off roads and destroyed crops, reducing the flow of produce into the city. Flooding disrupted planting cycles, forcing farmers to harvest prematurely and creating humid storage conditions favourable to aflatoxin growth, a hidden food safety threat that participants said often goes unnoticed until contaminated food reaches consumers. Damaged roads then forced traders onto longer alternate routes, hiring tractors at additional cost, expenses that were passed directly down the supply chain to shoppers in the form of higher prices.

The study’s systems mapping revealed that the largest number of drivers converge at the point of food retail and consumption, where their combined effects land hardest on food availability, affordability, and accessibility. This convergence helps explain a troubling cascade documented by participants: climate-driven shortages raise prices, rising prices push low-income households away from fresh produce toward cheaper, energy-dense processed foods, and that dietary shift in turn elevates the risk of diet-related noncommunicable diseases such as obesity and diabetes. One researcher interviewed for the study captured the substitution logic plainly, noting that when fruit and vegetables become inflated in cost, consumers choose bread over oranges, shifting toward processed options that carry long-term health consequences.

Equally revealing is how differently the various stakeholder groups perceived the same system. Retailers and young people working in the markets focused on climate impacts as disruptions to supply chains, prices, and the availability of goods. Experts and policymakers, by contrast, emphasised the effects of climate change on agricultural productivity. Community members highlighted food prices and economic constraints above all. Policymakers singled out land issues and inadequate policy frameworks, while experts flagged globalisation, urbanisation, and advertising as forces reshaping dietary habits. These divergent perceptions, the authors argue, are not noise to be averaged away but essential information, because they reflect each group’s position, power, and vulnerabilities within the food system itself.

That question of power runs through the paper’s most consequential argument. The researchers found that stakeholders’ roles and positioning within the city’s food system determine which impacts occur, which drivers are considered influential, and whose vulnerabilities persist. Youth and retailers, embedded in food retail and distribution, centred their concerns on access and affordability. Policymakers, oriented toward economic growth, prioritised productivity. Meanwhile, the informal food system that provides over 80 percent of Nairobi’s food distribution, retail, and purchases remains poorly integrated into formal regulatory frameworks, leaving it exposed to supply chain disruptions and limiting its capacity to deliver safe, nutritious diets. The study traces this structural stagnation to historical roots: Nairobi’s major markets, including Wakulima and City Market, have undergone minimal development since the 1960s, and planned expansions from 1970 were never implemented.

The technical details of the food supply chain illustrate how inefficiencies compound at every stage. Food travels from farms to primary markets on earth roads before continuing to Nairobi on tarmac, distributed informally by trucks, carts, private vans, passenger buses, and motorcycles. Packaging relies on sacks and crates, sometimes repurposed fertiliser sacks that can introduce harmful chemicals, and open vans expose produce to dust, exhaust fumes, and weather. Along this long chain of rural brokers, wholesalers, city intermediaries, and retailers, multiple taxation points drive up transaction costs, spoilage, and waste. One policymaker estimated that as much as 80 percent of what is produced never reaches a fork, ending up instead in landfills, roadsides, and dump sites, where it contributes to methane emissions.

Governance failures emerge as a decisive constraint on transformation. Although Kenya’s 2010 constitution devolved significant powers, resources, and functions such as agriculture and health to 47 counties, participants reported that the national government remains the primary lead and that sectoral policies often fail to address food systems because of limited awareness of how different sectors can contribute. Implementation of both sectoral and intersectoral policies is hampered by inadequate funding, limited capacity, transitioning governments, staff shortages, and resistance to change within departments. Kenya, like few other countries in the WHO Africa region, lacks food-based dietary guidelines, and although a food environment policy was drafted in 2018, participants described it as weak, with consumer awareness remarkably low. Unregulated television advertising was flagged as a particular concern, with one researcher reporting that roughly 40 percent of advertisements at peak viewing times promoted unhealthy foods.

Despite these entrenched problems, the study does not conclude that transformation is impossible, only that it remains limited under current conditions. The authors identify potential pathways including investment in cold-chain infrastructure, regulatory frameworks for the informal food sector, shortened supply chains, and strengthened intersectoral coordination across county boundaries, which is essential given Nairobi’s dependence on food from a broad geographic hinterland. They also extend the HLPE framework itself, arguing that while it offers a valuable systems-based approach, it requires local adaptation: it does not sufficiently unpack how political processes shape the entire system, nor does it capture the specific mechanisms and conditions under which drivers interact. The researchers recommend that future analyses explicitly map who holds power and how that power shapes priorities in practice.

The broader lesson extends well beyond Nairobi. Because food system drivers interact rather than operate in isolation, the authors argue that interventions must target combinations of active drivers within a specific context, demanding multisectoral collaboration and a genuine systems perspective. Siloed policies, they warn, are likely to prove ineffective unless the connections between climate, infrastructure, economy, and governance are addressed together, an approach consistent with frameworks such as Health in All Policies. For the millions of rapidly urbanising cities across sub-Saharan Africa, where over half the region’s population is projected to live in urban areas, the message is clear: global food system trends provide the backdrop, but it is local perceptions, local power dynamics, and local realities that determine whether transformation actually happens, and for whom.

Subject of Research: Stakeholder perceptions of the drivers and interactions shaping Nairobi's informal urban food system

Article Title: Do global food system trends reflect local realities? Perceptions of stakeholders

Article References: Tapkigen, J., Kaduka, L., Mbuka, S., Pulkki, J., Harding, S., & Koivusalo, M. (2026). Do global food system trends reflect local realities? Perceptions of stakeholders. PLOS Sustainability and Transformation, 5(10), e0000287. https://doi.org/10.1371/journal.pstr.0000287

Image Credits: AI Generated

DOI: 10.1371/journal.pstr.0000287

Keywords: urban food systems, Nairobi, climate change, food security, informal food sector, HLPE framework, food governance, stakeholder perceptions, sub-Saharan Africa, diet-related noncommunicable diseases, food supply chains, intersectoral policy