It is Tuesday afternoon and Refilwe leaves her job as a cleaner to begin her two-hour journey to her home in the Pretoria urban area of Mamelodi. After the minibus taxi drops her off a few streets from her home, she stops to buy vegetables from the street vendors at the taxi rank, before visiting a spaza store – a small-scale informal convenience store
(
1
)
– to buy tea, sugar and more food for her family’s dinner; she is already planning a trip to the large supermarket on the outskirts of her residential area on the weekend.
What is available for her to purchase at each of these venues? Imported rice, local white bread or traditional maize? Packaged biscuits, processed snack foods, or fruit and vegetables? What factors underlie her decisions to buy certain foods from different venues? What factors constrain or enable her to consistently source healthy food for her family?
These questions get to the heart of how consumers interact with the changing food supply patterns in urban Africa. As the emerging burden of diet-related non-communicable diseases establishes itself firmly alongside food insecurity and undernutrition in urban centres, nutrition policy research needs to consider in more detail the interaction between consumers and their food supply. Where are different foods purchased, and why? What influences consumer purchasing patterns, and how could policy be used to incentivize a food supply that delivers healthier food, where and when consumers need it?
In this commentary, we consider the benefits of food supply-focused research in identifying effective policy interventions to address the dual burden of malnutrition in Africa. We then highlight an under-researched dimension of the food supply chain, which is at the point of interaction with consumers, and provide a short case study from South Africa to illustrate the potential benefits of strengthening this research focus.
The dual burden of malnutrition in Africa and the changing food supply
The emerging dual burden of malnutrition in Africa is at a nascent stage; but persistent, high rates of undernutrition are increasingly accompanied by rising rates of overweight and risk factors for non-communicable diseases, particularly in urban areas(
Reference Tzioumis and Adair
2
,
Reference Popkin, Adair and Ng
3
). For example, in Burkina Faso, rates of overweight and obesity in an urban population were found to be 24 %, with similarly high rates of hypertension, hyperglycaemia and low HDL cholesterol. In addition, in 24 % of participants, one of these cardiometabolic risk factors was coexisting with either iron depletion or vitamin A deficiency, with a higher prevalence of this ‘double burden’ observed in the low-income group(
Reference Zeba, Delisle and Renier
4
). Similarly, a study in urban Kenya found a prevalence of childhood stunting of 46 % and underweight of 11 %, while 9 % of children were overweight/obese; 8 % of their mothers were underweight and 32 % were overweight/obese(
Reference Kimani-Murage, Muthuri and Oti
5
). The nutrition transition in urban South Africa is at an even later stage(
Reference Nnyepi, Gwisai and Lekgoa
6
). While the prevalence of stunting among children in South Africa has declined over the past 40 years, it remains at about 25 %(
Reference Said-Mohamed, Micklesfield and Pettifor
7
). At the same time, the recent South African National Health and Nutrition Examination Survey found a prevalence of obesity of 39 % among women and 11 % among men(
Reference Shisana, Labadarios and Rehle
8
), and high prevalences of impaired glucose levels (nearly 20 %) and diabetes (10 %).
As the urban population has increased in Africa, so has the challenge of delivering a safe, healthy, acceptable and affordable urban food supply(
Reference Dubbeling
9
). Healthier food choices are now often more expensive than commonly consumed, less healthy foods(
Reference Temple and Steyn
10
). Urbanization is changing job markets throughout the informal, semi-formal and formal economy, as well as impacting rural livelihoods (‘rubanization’) and food procurement patterns(
Reference Nielson
11
). Agricultural production is shifting away from subsistence agriculture, as rural households seek to diversify their livelihoods, yet large-scale agriculture still faces challenges in effectively supplying urban populations(
Reference Dubbeling
9
,
Reference Baiphethi and Jacobs
12
). Throughout sub-Saharan Africa, countries are experiencing increasing import dependence for staple food supplies, at the same time as a complex network of informal traders continues to operate across regional borders(
Reference Dubbeling
9
). Global and regional trade and investment are also increasing the availability and affordability of highly processed foods and sweetened beverages(
Reference Thow, Sanders and Drury
13
).
Urban populations demonstrate complex approaches to food procurement, including purchase from the formal and informal sectors, food transfers and own production(
Reference Crush and Frayne
14
). In particular, the informal sector (e.g. hawkers, small stores, informal roadside stalls) plays an essential role in making food accessible to the urban poor(
Reference Crush and Frayne
14
,
Reference Crush and Frayne
15
). However, there is also considerable evidence for the impact of formal food retailers on the food supply chain, particularly in terms of integrating supply chains and increasing buyer power, and a growing dependence of urban populations in Africa on purchased food(
Reference England
16
–
Reference Reardon and Hopkins
18
). Supermarket retail in Africa has grown substantially during the past two decades. For example, supermarkets in Kenya represented a tiny niche in the early 2000s but by 2005 had grown to represent a fifth of food retail, with half of their customers from low-income and poor consumers(
Reference Neven, Reardon and Chege
19
). However, there are often significant differentials in access to supermarkets between low-income and high-income populations, which contribute to food insecurity among the urban poor(
Reference Crush and Frayne
15
,
Reference Battersby and Peyton
20
,
Reference Crush and Caesar
21
).
Policy to improve the food supply
There is an urgent need for early, sustained policy intervention in Africa to avert the diet-related non-communicable disease epidemic experienced in other regions and to achieve the Sustainable Development Goals related to nutrition(
22
). Improving the food supply to support enhanced dietary quality and diversity will be an integral component of such intervention(
Reference Gelli, Hawkes and Donovan
23
). A food supply-based approach entails considering inputs into production, agricultural production, food processing and food retail to identify levers to help to improve the availability, accessibility, acceptability and affordability of healthier relative to less healthy foods(
Reference Hawkes
24
).
A food supply-based approach is essential for low- and middle-income countries, in which consumers are strongly influenced by affordability and availability, due to price sensitivity and often limited transport options. However, global recommendations for improving the food supply – such as fiscal policy intervention or labelling(
25
)
– tend to be most effective in the formal food sector, and the significant role of the informal food sector for urban consumers has created challenges for adapting these to lower-income contexts(
Reference Downs, Thow and Ghosh-Jerath
26
). In Lusaka, Zambia, among the poorest population quintile, only 1·2 % of staple purchases were made in supermarkets(
Reference Mason and Jayne
27
). In addition, general agriculture-focused intervention has a weak direct track record in flowing through to improvements in nutrition outcomes, likely due to the complex and gendered interaction between consumers and modern supply chains(
Reference Masset, Haddad and Cornelius
28
,
Reference Dangour, Hawkesworth and Shankar
29
).
This points to the need for food supply-focused research to support such policy intervention to address the dual burden of malnutrition in Africa, by identifying specific opportunities to improve access to (and consumption of) healthier foods. There is significant potential to improve affordability and availability of healthy foods in the African context, through in-depth analysis of the supply chain(
Reference Pinstrup-Andersen
30
). For example, researchers at the International Food Policy Research Institute have identified a wide range of strategies to identify food supply policy levers for reducing undernutrition in low- and middle-income countries, focusing on agriculture-sensitive intervention, intersectoral policy coherence and food-based approaches(
Reference Kadiyala, Harris and Headey
31
–
Reference Arimond, Hawkes and Ruel
35
). Similarly, food supply-focused research has been used to identify effective and feasible policy interventions to reduce trans-fats in both the formal and informal food system in India(
Reference Downs, Thow and Ghosh-Jerath
36
) and to identify a range of agricultural, commerce and trade policy interventions to improve the food supply in Pacific Island countries(
Reference Snowdon, Lawrence and Schultz
37
,
Reference Thow, Heywood and Schultz
38
). In South Africa, recent research regarding a sugar-sweetened beverage tax has highlighted the importance of – and likely effectiveness of – taking a food supply policy approach to improving nutrition(
Reference Tugendhaft, Manyema and Veerman
39
,
Reference Myers, Fig and Tugendhaft
40
).
But what about consumers?
The food supply-focused research described above generally focuses on the ‘production and distribution’ components of the food supply chain, and has revealed opportunities for a wide range of contextually relevant interventions with the potential to increase the affordability and availability of healthier foods relative to less healthy foods.
However, one of the key determinants of food security in urban Africa is food access; there is a complex interplay between the formal and informal sectors, as well as agricultural own production, in how urban populations access food(
Reference Crush and Frayne
15
). How consumers interact with their multiple food environments, particularly in a poor urban context, is still relatively unknown. A more ‘people-centred’ approach to food supply research that considers people as ‘choice makers’ rather than simply ‘consumers’ can help to unpack the two-way flow of information between the food supply and consumers; in particular, in understanding consumer decision making regarding where and why they choose to purchase different types of healthier and less healthy foods, including issues of convenience, acceptability, availability and affordability. Research that looks from a consumer perspective, ‘down’ the food supply chain, can thus complement our growing understanding of policy levers to improve affordability, accessibility and availability of healthier foods (Fig. 1).
Fig. 1 An opportunity to integrate a ‘consumer’ focus into food supply research for nutrition
The primary benefit of improved understanding of consumer engagement with food value chains by nutrition policy makers is the potential to enhance consumer access to healthier supply chains. For example, a combination of supply- and demand-based interventions might successfully increase affordability and availability of fruits and vegetables, as well as consumer demand and capacity for consumption (e.g. food skills). However, if the increased supply is mediated by supermarkets, and research into consumer interaction with supply chains indicates that these are accessed only by certain sub-populations, the impact of the intervention will be limited. Contextual understanding of consumer engagement with the food supply might lead to the strategic design of interventions such that the improvements to supply benefit a wider variety of retail outlets, including the informal sector.
How a consumer focus can add nutrition policy value: a case study of South Africa
South Africa continues to face the interrelated challenges of food insecurity, undernutrition and diet-related non-communicable diseases, and the need for a strong policy response is widely acknowledged(
Reference Haggblade, Duodu and Kabasa
41
,
Reference Muzigaba, Puoane and Sanders
42
). To return to our introductory case study, Refilwe’s decision making is occurring within a changing food supply and her decisions are shaped by complex historical, social, economic and personal factors(
Reference Battersby and McLachlan
43
). However, her decisions are also shaped by her limited access to healthy affordable food: she is likely to encounter a food environment that struggles to maintain a reliable supply of fresh fruit and vegetables for a growing urban population, expensive staple foods at local spaza stores with minimal economies of scale, pricing incentives that favour cheap highly processed foods and sweet beverages, and a requirement for convenience as the result of her own limited transport options, time and poor access to affordable cooking fuel(
Reference Temple and Steyn
10
,
Reference Thow, Sanders and Drury
13
,
Reference Igumbor, Sanders and Puoane
44
–
Reference Temple, Steyn and Fourie
46
).
Considering Refilwe’s access to fresh fruits as one important component of a healthy diet can help to exemplify how consideration of how, where, when and why consumers access food can be used to identify specific policy opportunities. Access to fruit in certain urban areas of South Africa is primarily through the informal market; in particular, wet markets or stalls and street vendors(
Reference Crush and Frayne
14
). Specific policy opportunities in South Africa that could increase access are: targeted support for peri-urban farmers to access urban markets (e.g. transport)(
Reference Mun Bbun and Thornton
47
); including food production considerations in initiatives for urban greening(
Reference Shackleton, Hebinck and Kaoma
48
); and, given the finding that fruit is one of the most commonly consumed street foods(
Reference Steyn, Labadarios and Nel
49
), initiatives that could increase access to, or incentivize the sale of, fresh fruit and vegetables by street vendors.
Expanding food supply research to address the double burden of malnutrition will require a multidisciplinary ethos covering a range of diverse fields of study from policy analysis to public health nutrition research, value chain analysis and consumer behaviour studies.
It is Tuesday afternoon and Refilwe leaves her job as a cleaner to begin her two-hour journey to her home in the Pretoria urban area of Mamelodi. After the minibus taxi drops her off a few streets from her home, she stops to buy vegetables from the street vendors at the taxi rank, before visiting a spaza store – a small-scale informal convenience store ( 1 ) – to buy tea, sugar and more food for her family’s dinner; she is already planning a trip to the large supermarket on the outskirts of her residential area on the weekend.
What is available for her to purchase at each of these venues? Imported rice, local white bread or traditional maize? Packaged biscuits, processed snack foods, or fruit and vegetables? What factors underlie her decisions to buy certain foods from different venues? What factors constrain or enable her to consistently source healthy food for her family?
These questions get to the heart of how consumers interact with the changing food supply patterns in urban Africa. As the emerging burden of diet-related non-communicable diseases establishes itself firmly alongside food insecurity and undernutrition in urban centres, nutrition policy research needs to consider in more detail the interaction between consumers and their food supply. Where are different foods purchased, and why? What influences consumer purchasing patterns, and how could policy be used to incentivize a food supply that delivers healthier food, where and when consumers need it?
In this commentary, we consider the benefits of food supply-focused research in identifying effective policy interventions to address the dual burden of malnutrition in Africa. We then highlight an under-researched dimension of the food supply chain, which is at the point of interaction with consumers, and provide a short case study from South Africa to illustrate the potential benefits of strengthening this research focus.
The dual burden of malnutrition in Africa and the changing food supply
The emerging dual burden of malnutrition in Africa is at a nascent stage; but persistent, high rates of undernutrition are increasingly accompanied by rising rates of overweight and risk factors for non-communicable diseases, particularly in urban areas( Reference Tzioumis and Adair 2 , Reference Popkin, Adair and Ng 3 ). For example, in Burkina Faso, rates of overweight and obesity in an urban population were found to be 24 %, with similarly high rates of hypertension, hyperglycaemia and low HDL cholesterol. In addition, in 24 % of participants, one of these cardiometabolic risk factors was coexisting with either iron depletion or vitamin A deficiency, with a higher prevalence of this ‘double burden’ observed in the low-income group( Reference Zeba, Delisle and Renier 4 ). Similarly, a study in urban Kenya found a prevalence of childhood stunting of 46 % and underweight of 11 %, while 9 % of children were overweight/obese; 8 % of their mothers were underweight and 32 % were overweight/obese( Reference Kimani-Murage, Muthuri and Oti 5 ). The nutrition transition in urban South Africa is at an even later stage( Reference Nnyepi, Gwisai and Lekgoa 6 ). While the prevalence of stunting among children in South Africa has declined over the past 40 years, it remains at about 25 %( Reference Said-Mohamed, Micklesfield and Pettifor 7 ). At the same time, the recent South African National Health and Nutrition Examination Survey found a prevalence of obesity of 39 % among women and 11 % among men( Reference Shisana, Labadarios and Rehle 8 ), and high prevalences of impaired glucose levels (nearly 20 %) and diabetes (10 %).
As the urban population has increased in Africa, so has the challenge of delivering a safe, healthy, acceptable and affordable urban food supply( Reference Dubbeling 9 ). Healthier food choices are now often more expensive than commonly consumed, less healthy foods( Reference Temple and Steyn 10 ). Urbanization is changing job markets throughout the informal, semi-formal and formal economy, as well as impacting rural livelihoods (‘rubanization’) and food procurement patterns( Reference Nielson 11 ). Agricultural production is shifting away from subsistence agriculture, as rural households seek to diversify their livelihoods, yet large-scale agriculture still faces challenges in effectively supplying urban populations( Reference Dubbeling 9 , Reference Baiphethi and Jacobs 12 ). Throughout sub-Saharan Africa, countries are experiencing increasing import dependence for staple food supplies, at the same time as a complex network of informal traders continues to operate across regional borders( Reference Dubbeling 9 ). Global and regional trade and investment are also increasing the availability and affordability of highly processed foods and sweetened beverages( Reference Thow, Sanders and Drury 13 ).
Urban populations demonstrate complex approaches to food procurement, including purchase from the formal and informal sectors, food transfers and own production( Reference Crush and Frayne 14 ). In particular, the informal sector (e.g. hawkers, small stores, informal roadside stalls) plays an essential role in making food accessible to the urban poor( Reference Crush and Frayne 14 , Reference Crush and Frayne 15 ). However, there is also considerable evidence for the impact of formal food retailers on the food supply chain, particularly in terms of integrating supply chains and increasing buyer power, and a growing dependence of urban populations in Africa on purchased food( Reference England 16 – Reference Reardon and Hopkins 18 ). Supermarket retail in Africa has grown substantially during the past two decades. For example, supermarkets in Kenya represented a tiny niche in the early 2000s but by 2005 had grown to represent a fifth of food retail, with half of their customers from low-income and poor consumers( Reference Neven, Reardon and Chege 19 ). However, there are often significant differentials in access to supermarkets between low-income and high-income populations, which contribute to food insecurity among the urban poor( Reference Crush and Frayne 15 , Reference Battersby and Peyton 20 , Reference Crush and Caesar 21 ).
Policy to improve the food supply
There is an urgent need for early, sustained policy intervention in Africa to avert the diet-related non-communicable disease epidemic experienced in other regions and to achieve the Sustainable Development Goals related to nutrition( 22 ). Improving the food supply to support enhanced dietary quality and diversity will be an integral component of such intervention( Reference Gelli, Hawkes and Donovan 23 ). A food supply-based approach entails considering inputs into production, agricultural production, food processing and food retail to identify levers to help to improve the availability, accessibility, acceptability and affordability of healthier relative to less healthy foods( Reference Hawkes 24 ).
A food supply-based approach is essential for low- and middle-income countries, in which consumers are strongly influenced by affordability and availability, due to price sensitivity and often limited transport options. However, global recommendations for improving the food supply – such as fiscal policy intervention or labelling( 25 ) – tend to be most effective in the formal food sector, and the significant role of the informal food sector for urban consumers has created challenges for adapting these to lower-income contexts( Reference Downs, Thow and Ghosh-Jerath 26 ). In Lusaka, Zambia, among the poorest population quintile, only 1·2 % of staple purchases were made in supermarkets( Reference Mason and Jayne 27 ). In addition, general agriculture-focused intervention has a weak direct track record in flowing through to improvements in nutrition outcomes, likely due to the complex and gendered interaction between consumers and modern supply chains( Reference Masset, Haddad and Cornelius 28 , Reference Dangour, Hawkesworth and Shankar 29 ).
This points to the need for food supply-focused research to support such policy intervention to address the dual burden of malnutrition in Africa, by identifying specific opportunities to improve access to (and consumption of) healthier foods. There is significant potential to improve affordability and availability of healthy foods in the African context, through in-depth analysis of the supply chain( Reference Pinstrup-Andersen 30 ). For example, researchers at the International Food Policy Research Institute have identified a wide range of strategies to identify food supply policy levers for reducing undernutrition in low- and middle-income countries, focusing on agriculture-sensitive intervention, intersectoral policy coherence and food-based approaches( Reference Kadiyala, Harris and Headey 31 – Reference Arimond, Hawkes and Ruel 35 ). Similarly, food supply-focused research has been used to identify effective and feasible policy interventions to reduce trans-fats in both the formal and informal food system in India( Reference Downs, Thow and Ghosh-Jerath 36 ) and to identify a range of agricultural, commerce and trade policy interventions to improve the food supply in Pacific Island countries( Reference Snowdon, Lawrence and Schultz 37 , Reference Thow, Heywood and Schultz 38 ). In South Africa, recent research regarding a sugar-sweetened beverage tax has highlighted the importance of – and likely effectiveness of – taking a food supply policy approach to improving nutrition( Reference Tugendhaft, Manyema and Veerman 39 , Reference Myers, Fig and Tugendhaft 40 ).
But what about consumers?
The food supply-focused research described above generally focuses on the ‘production and distribution’ components of the food supply chain, and has revealed opportunities for a wide range of contextually relevant interventions with the potential to increase the affordability and availability of healthier foods relative to less healthy foods.
However, one of the key determinants of food security in urban Africa is food access; there is a complex interplay between the formal and informal sectors, as well as agricultural own production, in how urban populations access food( Reference Crush and Frayne 15 ). How consumers interact with their multiple food environments, particularly in a poor urban context, is still relatively unknown. A more ‘people-centred’ approach to food supply research that considers people as ‘choice makers’ rather than simply ‘consumers’ can help to unpack the two-way flow of information between the food supply and consumers; in particular, in understanding consumer decision making regarding where and why they choose to purchase different types of healthier and less healthy foods, including issues of convenience, acceptability, availability and affordability. Research that looks from a consumer perspective, ‘down’ the food supply chain, can thus complement our growing understanding of policy levers to improve affordability, accessibility and availability of healthier foods (Fig. 1).
Fig. 1 An opportunity to integrate a ‘consumer’ focus into food supply research for nutrition
The primary benefit of improved understanding of consumer engagement with food value chains by nutrition policy makers is the potential to enhance consumer access to healthier supply chains. For example, a combination of supply- and demand-based interventions might successfully increase affordability and availability of fruits and vegetables, as well as consumer demand and capacity for consumption (e.g. food skills). However, if the increased supply is mediated by supermarkets, and research into consumer interaction with supply chains indicates that these are accessed only by certain sub-populations, the impact of the intervention will be limited. Contextual understanding of consumer engagement with the food supply might lead to the strategic design of interventions such that the improvements to supply benefit a wider variety of retail outlets, including the informal sector.
How a consumer focus can add nutrition policy value: a case study of South Africa
South Africa continues to face the interrelated challenges of food insecurity, undernutrition and diet-related non-communicable diseases, and the need for a strong policy response is widely acknowledged( Reference Haggblade, Duodu and Kabasa 41 , Reference Muzigaba, Puoane and Sanders 42 ). To return to our introductory case study, Refilwe’s decision making is occurring within a changing food supply and her decisions are shaped by complex historical, social, economic and personal factors( Reference Battersby and McLachlan 43 ). However, her decisions are also shaped by her limited access to healthy affordable food: she is likely to encounter a food environment that struggles to maintain a reliable supply of fresh fruit and vegetables for a growing urban population, expensive staple foods at local spaza stores with minimal economies of scale, pricing incentives that favour cheap highly processed foods and sweet beverages, and a requirement for convenience as the result of her own limited transport options, time and poor access to affordable cooking fuel( Reference Temple and Steyn 10 , Reference Thow, Sanders and Drury 13 , Reference Igumbor, Sanders and Puoane 44 – Reference Temple, Steyn and Fourie 46 ).
Considering Refilwe’s access to fresh fruits as one important component of a healthy diet can help to exemplify how consideration of how, where, when and why consumers access food can be used to identify specific policy opportunities. Access to fruit in certain urban areas of South Africa is primarily through the informal market; in particular, wet markets or stalls and street vendors( Reference Crush and Frayne 14 ). Specific policy opportunities in South Africa that could increase access are: targeted support for peri-urban farmers to access urban markets (e.g. transport)( Reference Mun Bbun and Thornton 47 ); including food production considerations in initiatives for urban greening( Reference Shackleton, Hebinck and Kaoma 48 ); and, given the finding that fruit is one of the most commonly consumed street foods( Reference Steyn, Labadarios and Nel 49 ), initiatives that could increase access to, or incentivize the sale of, fresh fruit and vegetables by street vendors.
Expanding food supply research to address the double burden of malnutrition will require a multidisciplinary ethos covering a range of diverse fields of study from policy analysis to public health nutrition research, value chain analysis and consumer behaviour studies.
Acknowledgements
Financial support: This work was partially supported by the Australia Africa Universities Network (AAUN) grant held by J.N. for 2015, titled ‘Where does your food come from? Food supply in the context of trade, agriculture and nutrition’. The AAUN had no role in the design, analysis or writing of this article. Conflict of interest: None. Authorship: All authors contributed to the research questions identified in the commentary. A.M.T. drafted the manuscript and all authors contributed to the writing. Ethics of human subject participation: No ethical approval was required for the work presented herein.