The High Cost of Cheaper Food
BYLINE: Jonathan Crush
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. …