Many of these consumers do not consider themselves undernourished, but experts say consuming cheap food, cooked and sold under unhygienic conditions, could be affecting the nutrition and health of many urban poor.
"Many of the people living in informal settlements are poor and rely on street food vendors for their consumption... The food is, in most instances, very unhygienic," Kwadwo Asenso-Okyere, the International Food Policy and Research Institute’s (IFPRI) Eastern and Southern Africa director, told IRIN. "When you get little money in the slums, you either prioritize to buy food or paraffin, and they tend to decide on buying already cooked food."
Eating cheap, cooked foods is one of the many strategies employed by the urban poor to cope with rising global food prices. Experts say there is a need to create policies to ensure that this segment of the world’s population can access a proper diet.
"Their vulnerability to food price increases means there should be ways to ensure they can access a balanced diet, like promoting urban agriculture and providing them with social protection," Anne O'Mahoney, the Kenya country director for the global NGO Concern Worldwide, told IRIN.
In Kenya, a recent assessment carried out by the government, the Famine Early Warning Systems Network (FEWS NET), and the UN’s World Food Programme and Food and Agriculture Organization revealed that more than a quarter of the country’s urban children are stunted - a symptom of chronic malnutrition - while 13 percent of high-density urban households have unacceptably low levels of food consumption.
A 2010 study by the University of Colombo, in Sri Lanka, found that just 38.4 percent of children had at least one fruit portion a day, while legume and nut consumption was seen in only 34.4 percent. "Inadequate dietary diversity in urban slums is a concern," the authors concluded.
A variety of factors are known to improve nutrition among the poor.
Educating women, for example, has been shown to benefit their families’ diets. "When women are educated, they have a better view of nutrition, and this translates into better outcomes for their families," O’Mahoney said.
IFPRI's Asenso-Okyere points out that, because urban populations rely solely on the market for their meals, linking rural producers to markets will ensure the urban poor can access affordable food.
Clean water is also critical, O'Mahoney said. "Good diet will be important, but ability to ward off waterborne disease and ensure urban households can make their environment hygienic will depend on their ability to access clean water."
A 2012 study of living conditions in the slums of Dhaka, Bangladesh, by research group Unnayan Onneshan, found almost half of 856 children studied were suffering from different types of waterborne diseases. Sixty-seven percent also suffered from diarrhoea, a major cause of malnutrition. The study found that, even though the children regularly ate three meals a day, inadequate quality and lack of dietary diversity were problems.
The seventh Global Hunger Index, which uses data from 79 countries, shows that 20 countries - many in South Asia and sub-Saharan Africa - have hunger levels considered either “alarming” or “extremely alarming”. Unsustainable use of land, water and energy are, according to the report, the biggest threats to food security among the world's poor and vulnerable.
In addition to population growth, the authors noted that "migration from rural to urban areas in developing countries will have significant effects on food consumption patterns… When people move to urban areas, they tend to eat fewer basic staples and more fruits, livestock products, and cereals requiring less preparation.”
Experts recommend promoting initiatives such as urban agriculture and bag farms to enable slum dwellers to grow more nutritious foods. But broader reforms are also required, “like ensuring the urban poor have leases or titles to the land they live on," Concern's O'Mahoney said.