Undernutrition is well recognised as a crisis in developing countries, but a second “silent emergency” – obesity – now poses a major threat to public health in countries experiencing rapid urbanisation such as South Africa. While obesity was once associated with rising incomes and industrialised societies, this is no longer the case. Modern urban diets, characterised by cheap carbohydrates and sugar, affect mostly the poor in the context of massive rural-urban migration.

Given the speed of urbanisation and the considerable population growth expected in the cities of the developing world over the coming decades – some three billion by mid-century – the burden of disease related to obesity and undernutrition threatens to overwhelm the capacity of the health care system and other social services in many countries.

Obesity is about far more than simply over-eating. In many urban food markets, the industrial food processing and supply system has replaced traditionally nutritious foods that are still available in many rural areas with nutritionally inferior but energy-dense and cheaper food and drink.

As well as being nutritionally poor, these cheaper foods typically comprise highly refined, low-fibre cereals, fats and sugar. This diet is associated with many non-infectious health conditions and diseases, and the burden is increasingly being carried by the urban poor.

In the urban context, food accessibility and dietary quality are the critical determinants of household and individual nutritional status. A recent baseline food security survey by the African Food Security Urban Network (Afsun) in 11 cities in nine southern African countries showed that three-quarters of households in poor urban areas were food insecure. While less than 10 percent of households reported that they often experienced an absolute shortage of food or often went hungry, many ate smaller or fewer meals a day.

They said they often did not eat their preferred diet, ate food that they did not like and food that lacked diversity. In other words, problems of nutrition in the urban context may be as much about what people can afford to eat as how much they can eat.

In cities, income is a critical determinant of food accessibility. While increases in income do, in general, result in greater spending on food, whether this increased spending improves nutritional status among poorer urban households is a question that has not been adequately addressed and needs further research.

The levels of food processing and convenience foods that prevail in urban food markets mean that greater diversity may not result in improvements in nutritional quality and may even result in a deterioration of nutritional status. There has been a substantial rise in sales of ready-made meals and other processed foods in South Africa’s cities and towns in the past decade. Also, supermarkets in low-income urban areas tend to stock less fresh produce than their counterparts in other parts of the city.

Studies have shown that lower-calorie and nutrient-dense foods such as fruits and vegetables generally do cost more, and that cost is a barrier to the urban poor. Less healthy versions of particular foodstuffs also tend to cost less. A study of food prices in 14 small towns in the Western Cape, published in the journal Nutrition in 2011, compared the prices of six commonly consumed foods with healthier versions of those foods (for example, wholewheat bread versus white bread).

Healthier foods cost between 10 percent and 60 percent more when compared on a weight basis, and between 30 percent and 110 percent more when compared based on the cost of food energy. For a household of five, the increased expenditure of a healthier diet would be more than R12 000 a year, a high proportion of total household income for most of the population.

While under-weight people are generally malnourished in a developing world context, it is also possible for over-weight and obese people, who rely on a diet of refined carbohydrates, fats and sugar, to be malnourished. In South Africa’s cities more research on the quality of diets and dietary diversity is therefore required to establish both the levels and the quality of macro- and micro-nutrient intake among the urban poor. Dietary diversity is particularly low in urban informal areas.

The Department of Health’s recently released strategy document is a step in the right direction with its acknowledgement that affordability and accessibility are the greatest hindrances to healthy eating.

The Strategic Plan for the Prevention and Control of Non-Communicable Diseases 2013-2017 notes that there is a shortage of fresh fruit and vegetables and other healthy foods in most informal areas, and acknowledges the need for government intervention to enable access to nutritious foods.

The first thing the Trade and Industry Ministry could do in this regard is ensure that the revisions now being made to the Licensing of Businesses Bill remove this proposed legislation’s threat to street traders and other informal entrepreneurs.

Afsun’s research shows that the urban informal food economy plays a vital role in providing affordable food for poor households in South African cities. Remove this food source, in which street traders play an important role, and these households will plunge even deeper into food insecurity.

As far as schools are concerned, while education about which foods are healthy is necessary, more important is what children have to eat during their day in the classroom. There is little point in giving them textbooks pointing out the merits of eating an apple and then selling them sweets and other junk food in the tuckshop.

Most of the research on the connections between food insecurity and poor nutrition has focused on physiological outcomes. While impaired brain development in infancy and childhood is one of those outcomes, far less attention has been paid to the psychological dimensions and outcomes of poor nutrition and food insecurity on the mental health of adults.

There is therefore an urgent need to supplement the focus on physical health with an exploration of the relationships between food insecurity, nutrition and mental well-being.

A 2009 study of children in townships around Cape Town concluded that while food security, access to social welfare grants, employment in the household and access to school were all associated with better psychological health, food security showed the most consistent association with reduced psychological problems.

Another issue that needs to be considered in policy-oriented research in our cities is the vicious cycle of nutrition and communicable disease such as HIV and TB. How poor nutrition hastens the advance of Aids and how HIV and Aids impact on the nutritional requirements of sufferers are important questions. While there is a considerable body of biomedical research on nutrition and HIV, our understanding of the broader linkages between HIV and urban food security is much less refined.

Food policy is generally seen as something to be formulated and implemented, not researched. However, given the scope and complexity of the problems of urban nutrition, it is important to research and evaluate the successes and failures of past programmes. This applies both to the nutrition policies of national and local governments and the programmes of international organisations. Even government policies that appear most promising have the potential to founder on the rocks of inadequate resourcing, lack of political ownership and intra-departmental competition.

While food insecurity in Africa has risen to the top of the international development agenda over the past decade, most of the policy and research emphasis is on rural poverty and malnutrition. Important as it is to find ways to overcome these problems, Africa faces an increasingly urban future and urbanisation per se is not the panacea for food insecurity. Access to good, healthy food is what the urban poor need for a more productive and longer life.

Food policy is generally seen as something to be formulated and implemented, not researched. However, given the scope and complexity of the problems of urban nutrition, it is important to research and evaluate the successes and failures of past programmes
The opinions expressed in this article/multimedia are those of the author(s) and do not necessarily reflect the views of CIGI or its Board of Directors.