Mapping the consumer foodshed of the Kampala city region shows the importance of urban agriculture

Sub-Saharan Africa is experiencing rapid urbanisation alongside high levels of food insecurity, intensified by global shocks such as COVID-19 and the Russia-Ukraine war. Urban growth is transforming consumption and production patterns and reshaping supply chains. Urban demand is rising, and middle- to high-income groups are shifting towards more protein-rich and animal-based diets. Meanwhile, urban expansion threatens croplands in urban and peri-urban zones, affecting regional food provision. There is ongoing debate on the role of urban agriculture in urban food systems. Some argue its contribution to urban foodsheds is limited and raise concerns over food quality and safety, while others find positive associations with dietary diversity and emphasize co-benefits such as reduced transport costs and climate adaptation. Access to urban agricultural land often favors established urban dwellers over recent migrants. Authorities frequently frame food systems as rural production issues, delaying integration into urban planning. However, food accessibility—shaped by poverty, socio-economic segregation, proximity, price volatility, market disruptions, and land-use change—is a core urban challenge. As cities influence peri-urban and rural production and connect to global markets, understanding foodsheds—the geographic areas from which populations derive food—is critical. While localized foodsheds can reduce transport costs and emissions and strengthen local economies, over-reliance on local self-sufficiency may reduce resilience to shocks; diversified, multi-scalar foodsheds are recommended. There is a gap in empirical, spatially explicit foodshed mapping methodologies in SSA, especially from the consumer perspective and incorporating informal systems. This study aims to: (i) trace the locations of food sources for households across socio-economic groups and vendor types, and (ii) quantitatively map and delineate household foodsheds across geographic scales, starting from consumers and tracing food via vendors to origins.

The paper reviews debates on urban agriculture’s role in SSA food systems, contrasting studies that find limited contributions and potential quality/safety issues with those highlighting positive links to dietary diversity and climate co-benefits. It situates foodshed concepts in prior literature that advocates for localized systems and urban self-sufficiency, noting potential advantages (reduced transport costs/emissions, strengthened local economies) and vulnerabilities (reduced resilience to shocks). The authors discuss calls for diversified foodsheds balancing local, regional, and global supply to mitigate risks. They identify a methodological gap in empirical foodshed mapping in SSA, where most studies focus on potential capacity (largely North American/European cases) or supply-side flows (e.g., West African city studies counting shipments) rather than consumer-origin tracing in semi-informal systems. The review underscores the need for integrated, consumer-centered, spatial methods capturing informal vendors and urban agriculture.

Study area and design: Greater Kampala Metropolitan Area (GKMA), Uganda. The study adopts a consumer-centric foodshed tracing approach: from household consumption to vendor acquisition points and then to the geographic origins of foods. Data collection: 541 households surveyed across 25 parishes in GKMA (March–April 2021) using a purposive sampling strategy to capture socio-economic variation, facilitated by a local representative and informed consent. The household survey comprised five parts: demographics, socio-economic characteristics, food accessibility, dietary diversity, and food security metrics. Households were asked to list their five main staple foods (respondent-defined) and where they obtained them, including amounts/spending. Vendor data: Parallel surveys of food vendors across commerce types, including mobile street vendors, fixed street vendors, market vendors, retailers, supermarkets, and wholesalers. A vendor table reports categories and counts (e.g., mobile street vendors n=16, fixed street vendors n=112, market vendors n=112, retailers n=7, supermarkets n=3, wholesalers n=3; total dataset n=303). A separate vendor inventory recorded 1,100 food items sold (85 unique types). Data processing: Expenditures converted to Ugandan Shillings (UGX). Average spending per person per day computed using household size. Staple foods analysis retained whole foods; processed/ambiguous items without vendor-origin data were excluded (e.g., tea n=2, rölex n=2, coffee n=1, Ethiopian food n=1, grasshopper n=1, cheese n=1, yoghurt n=1, fries n=1, pizza n=1). Foodshed mapping: For each household staple food, the vendor source was identified; vendor-reported origins were traced to parishes (GKMA), districts (Uganda), or countries (international). Monetary equivalents (UGX/person/day) were aggregated by spatial unit. An OpenStreetMap-based shapefile was used to visualize foodsheds in ArcGIS v10.7.1. Foodsheds were delineated as minimal areas containing 25%, 50%, 75%, and 95% of the total foodshed value, and cumulative foodshed shares were plotted against distance from Kampala for socio-economic clusters and vendor types. FAO (2010) food groups were used to analyze foodshed by commodity group. Validation and analytics: Cross-validation using Python v3.9.7 with K-folds (K=10). Root mean squared error (RMSE) of cumulative foodshed curves was calculated for test vs. training folds; average RMSE across folds was 5.9%, with all but one test fold below 5.6%. Summary expenditure checks: total combined staple foodshed value 13,111.79 UGX/day, equivalent to 371 UGX/person/day for staples, consistent with independently reported daily food expenditure per person in the dataset (3,781 UGX) and UBOS estimates (4,451 UGX/person/day, 2012/2013).

- Spatial extent: 50% of Kampala’s consumed food originates within 120 km of the city; approximately 10% originates within the city itself. - Relative importance of sources: Urban agriculture currently contributes about twice as much to urban food provision as international imports. - Socio-economic differences: Established high-income urban dwellers have a more local foodshed, primarily due to participation in urban agriculture. Low-income newcomers rely heavily on retailers sourcing from rural Uganda. For low-income newcomers, only 5.2% of their foodshed is sourced within Kampala; they are the only group whose 70% foodshed can be mapped within 200 km of Kampala. Despite distinct diets and food security levels across groups, cumulative foodshed sizes are similar. - Household sourcing patterns: On average, households obtain staples from retailers (42.0%), market vendors (26.0%), and fixed street vendors (20.0%). Supermarkets contribute about 1.0% of staple sourcing, with slightly higher shares for middle/high-income households (1.9% and 1.6%) and negligible for low-income households. 76.2% of staple food items are obtained within a 10-minute walk. - Own production: Households produce on average 7.4% of the value of staple foods themselves (UBOS reports 5.4% for Kampala, 2018/2019). Established high-income households produce about 15.7% of their own staples. - Vendor sourcing structure: Vendor sourcing shares (UGX/day equivalent) indicate reliance on middlemen (dataset average 42.7%), direct farms (18.6%), other food markets (35.1%), limited home-grown by vendor (2.5%), and minimal from family/friends (1.1%). Supermarkets and wholesalers source heavily via middlemen; mobile street vendors often source from other markets. - Commodity-level patterns: About 30% of cereals are imported (notably rice from Pakistan). Vendor types reflect product specializations: mobile street vendors emphasize other fruits (41.5%) and fish/seafood (31.6%); market vendors emphasize white roots/tubers (40.8%) and flesh meats (36.2%); fixed street vendors focus on flesh meats (49.4%) and white roots/tubers (19.4%); retailers emphasize cereals (47.0%), legumes/nuts/seeds (20.3%), and dairy (15.0%). - Foodshed shapes: Established high-income groups exhibit highly local 25% and 50% foodsheds; newcomers’ foodsheds are more convex, indicating reliance on more distant sources.

The study demonstrates that Kampala’s consumer foodshed is predominantly local–regional, with half of consumed food originating within 120 km and a meaningful 10% from within the city. Urban agriculture emerges as a key contributor, especially for established high-income households, underscoring its role in local resilience, dietary diversity, and reduced dependence on long-distance supply chains. Conversely, low-income newcomers rely on proximate retail outlets that in turn source from rural districts, revealing vulnerabilities tied to price volatility and supply disruptions. The findings nuance concerns about supermarketization in SSA: supermarkets currently account for a negligible share of staple acquisition, while informal and traditional retail channels dominate and are highly accessible (most staples acquired within a 10-minute walk). This underscores the centrality of neighborhood-scale markets and vendors in urban food access. Projected dynamics—ongoing urban sprawl, climate change impacts, and continued shifts toward animal protein—are likely to expand and reshape the foodshed, potentially eroding urban agricultural land and increasing exposure to climate risks within national borders. A larger, more diversified, multi-scalar foodshed could enhance resilience but may entail higher transport costs and emissions. The study highlights that urban agricultural participation is associated with a more local foodshed among higher-income, established residents; however, equitable access to land and resources remains a policy challenge. Establishing baseline, spatially explicit foodsheds enables monitoring of changes over time and targeting interventions to critical production regions.

This study provides one of the first empirical, consumer-centered mappings of a Sub-Saharan African city’s foodshed, integrating data from households and vendors to trace staple foods back to their origins. It shows that Kampala’s foodshed is largely local–regional, with 50% of food originating within 120 km and urban agriculture contributing significantly—currently twice the magnitude of international imports. Socio-economic disparities shape foodshed locality: established high-income residents’ participation in urban agriculture yields more local sourcing, while low-income newcomers depend more on retailers sourcing from rural areas. The dominance and accessibility of informal and traditional retail channels are reaffirmed. The approach offers a replicable framework for cities to quantify and visualize foodsheds across scales, informing land-use planning, urban agriculture policy, and climate resilience strategies. Future research should: (i) assess nutritional quality and safety of locally grown foods, (ii) examine how urbanization, climate change, and dietary shifts alter foodshed size and composition and urban food security, (iii) investigate the city’s role in redistributing food to peri-urban and rural areas, and (iv) expand vendor and market coverage, especially for supermarkets/wholesalers, to refine international sourcing estimations.

- Sampling and representativeness: Households were geographically distributed but may not fully represent all residents. The definition of “staple foods” was respondent-driven (calories, spending, weight, or preference), introducing variability. - Measurement scope: Foodshed values are estimates rather than precise supply chain quantities, a common limitation in empirical foodshed studies including urban agriculture. - Recall and origin accuracy: Vendor-reported origins depend on recall and supplier relationships; while vendors often know their sources, this introduces uncertainty. - Exclusions: Some processed or ambiguous foods lacking vendor-origin data were excluded from analysis. - Vendor and market sample sizes: Small samples for supermarkets and wholesalers (n=7 each) limit inferences about international sourcing; only three major markets were included relative to the size of Kampala. - External flows: The study did not quantify redistribution of food from Kampala to peri-urban or rural areas. - Validation limits: While K-fold cross-validation yielded an average RMSE of 5.9%, one fold exceeded 5.6%, and results remain contingent on the specific survey period and methods.