The lifestyle altering effects of westernisation could be responsible for the high prevalence of obesity, and associated health risks in sub-Saharan Africa, researchers have found.
The study, published in PLOS ONE, by a team from the University of Warwick Medical School found that over one in five women in Nigeria were reported to be overweight or obese, with this statistic increasing among demographics with improved social and economic indicators.
Those women classed as having a higher socio-economic status were three and a half times more likely to be overweight or obese when compared to those in the lowest status bracket. Access to higher levels of education also increased risk, as did urbanisation; 36.4% of women in urban areas were overweight compared with 18.8% in more rural districts.
"Obesity is now not just a western problem, but an African one as well" argues Dr Ngianga-Bakwin Kandala. "By becoming wealthier, better educated and urbanised regions of Nigeria are gaining the attributes we would more commonly associate with western societies. This has brought both a change in lifestyle and diet that is reflected in finding that educated, wealthy women are much more likely to be obese than those living in more rural, traditional areas".
Professor Saverio Stranges explained, "Urbanisation, and the shift towards what we would consider to be more western habits, appears to come hand in hand with a more sedentary lifestyle and change in diet. More people have cars and drive where they might have walked in the past. The rise in internet usage within the cities sees more people sat down for prolonged periods, both at home and at work."
"This physical inactivity is worsened by a less balanced diet. An over reliance on energy dense processed foods can be highlighted by the growing presence of fast food outlets and the knock on effect is reducing the intake of staple, low calorie foods."
This, alongside data from several other countries, suggests that rising urbanisation and improvements in developmental indicators leads to concurrent under and over nutrition in the population.
This stands to be a continuing problem. In 1995, only 35% of the African population resided in urban areas, a figure projected to rise to 54% by 2030.
Professor Stranges continued, "The worry is that Nigeria, like many Sub-Saharan African countries, is facing a major public health challenge with a rising number of overweight adults, whilst large segments of the population face problems associated with under nutrition. This dual burden will mean combating both malnutrition and the risks associated with obesity, such as cardiovascular disease."
Most epidemiological research in Sub-Saharan Africa has focused under nutrition, particularly within women and children who are deemed to be in the more vulnerable demographics of the population. This new study reflects a growing trend to look at other nutrition problems, and is the first of its kind to do so down to a state level.
The study used data from the 2008 Nigerian Demographic and Health Survey. Around 28,000 women aged between 15 and 49 years old were sampled, of which 20.9% were recorded as being overweight or obese.
Dr Ngianga-Bakwin Kandala added, "Using such a vast representative population sample we are able to paint a more accurate picture of variances between the individual states for the first time. Lagos State, home to one of the fastest growing cities in the world, reported that over 50% of the women were overweight or obese, whereas the more rural Yobe State in the North East was closer to just 10%."
"Seeing this data broken down across the states will help to understand both the social and economic burden of obesity, and the future demand upon public health in each state."
When taking urbanisation and other risk factors into account, the South Eastern states of Cross River, Akwa Ibom, Rivers, Bayelsa and Taraba were shown to have the most significant spatial correlation to being overweight or obese.
With the exception of Kebbi State, those in the north and west had a markedly lower correlation with obesity.