Our cities are making us fat and sick. Southern Africa is one of the fastest-urbanising parts of the world, and by the middle of this century over half of its populace will be city dwellers.
But the shift from a pastoral life in the countryside into the concrete jungle comes with a change in lifestyle and food choices that pushes us to the wrong side of our ideal goal weight. We abandon the traditional foods we grew up on, and start eating highly processed, often junk foods. Ironically, though, this ‘nutritional transition’ is making us gain weight at the same time as we are getting malnourished.
Together, all these shifts in the world around us are changing what appears on the plate in front of us each day – if, indeed, a meal even involves a plate or sitting down at a table. This increased exposure to fast foods, decreases in the relative cost of meat and high fat foods, and reduced time for food preparation are all changing dietary patterns in the urban setting.
Until a couple of decades ago the African population consumed a typical traditional diet, where the fat intake was only 16% of the total calories. By 1990 the fat intake in an urban African community had increased to 26%. People who lived in cities for most of their lives consumed a typical westernized diet with 30% of calories from total fat, while those who had spent less than 20% of their lives in the city only consumed 22.5% of calories from total fat.
Similarly when rural people in the North West province moved into the city, the proportion of consumed energy coming from fat in the diet increased from 22% in the rural population to 31% in the settled urban population. Other studies report fat intakes of 34% and 40% among African urban populations.
Urbanites, rich and poor alike, have less time on their hands, a bit more money in their pockets, and are surrounded by cheap, convenient food that is engineered to provide a high and keep them hooked. It is no wonder we are getting fat and sick. Life in the country may be tough and physically demanding, but at least it keeps us fit and strong.
Slotting ourselves into the modern, urban treadmill tends to make us a lot more sedentary, which, while it may feel good in the moment, can be brutal for our health.
The cities we move into take so much of the physical toil out of life – cars, trains, buses, elevators and escalators to move us; elaborate road and rail systems to deliver to us the goods and services that we once had to travel considerable distances to get for ourselves; electricity and water-sanitation grids that mean we do not have to go hunting for fuel, water or safe places to ablute.
Modern media – television, mostly – encourages not only sedentary recreation, but often the mindless wolfing down of calories at the same time (there is extensive research to show how much our energy intake increases when we are eating in front of the telly, without paying attention to taste, texture, chewing or feelings of satiety).
People also tend to start using more tobacco when they settle into cities, which, together with the tendency to become couch potatoes, only compounds the effects of our deteriorating diet. Writing in The Lancet, Dr Benjamin Caballero points out just how the built environment impacts on the energy-in/energy-out balance of people’s daily calorie use, since ‘mechanization and automation have sharply reduced the amount of energy we need to spend in basic survival activities and at work’.
‘Until recently,’ he says, ‘the obesity field was largely unfamiliar with the quantification of environmental variables such as air pollution, traffic patterns, and urban density, which have been widely used in environmental and occupational health. There are now incipient efforts to identify major factors in the built environment associated with excess weight gain.’
Simply put, modern city life makes it too easy to make bad food-lifestyle choices, and too hard to make good ones, as the UK’s House of Lords recent report on behaviour change and obesity puts it. The net result: more calories, and not necessarily high-nutrient ones, delivered more easily, with fewer opportunities to burn them off.
In South Africa, for instance, over half of adults are overweight or obese, according to the World Bank; yet nearly 20% of children under nine are stunted from malnutrition. These statistics do not come from opposite ends of the socio-economic spectrum – starving on one side; overfed (and perceived as gluttonous and lazy) on the other.
Counter-intuitive as it may seem, the communities where we are seeing rising obesity are often the same as those where there is a dangerous shortfall of vitamins and minerals. The very fact that these empty calories are often so cheap and accessible is why the burden of obesity, which first started plaguing rich countries in the global north in the 1970s, has crept insidiously into poorer communities, creating this double burden of disease.
People are not getting enough nutrients (so they are undernourished nutritionally) but are getting more calories than they need (so they are also overnourished in terms of basic energy requirements). You end up with a malnourished person living inside the skin of an overweight or obese body.
Now this person has to shoulder the double burden of disease: the stunting, development or health problems associated with being malnourished, but also with the chronic lifestyle-related diseases associated with being overweight.
In parts of the developing world, these lifestyle-related diseases (the so-called ‘non-communicable diseases’), such as diabetes, heart disease or certain cancers associated with being overweight, are outstripping the communicable diseases usually associated with poor communities, such as HIV/AIDS or TB.
By Leonie Joubert