The trend and factors influencing BMI (overweight, obesity and underweight) among Ghanaian women was investigated using a large sample size data collected nation-wide over a 15-year period. This is the first study to report trends in the prevalence of overweight and underweight among women in Ghana using nationally representative sample. Disparities in overweight, obesity and underweight were found by age, level of education, parity, marital status, wealth index and survey year. Furthermore, there were rural–urban differences in both underweight and overweight. In the general Ghanaian women population, the prevalence of overweight and obesity has consistently increased over the 15-year period (1993–2008). However, the prevalence of underweight was nearly the same between 1993 and 1998, and slightly decreased thereafter. By rural–urban stratification, it was observed that the prevalence of overweight and obesity have consistently increased from 1993 to 2008 in urban settings. The only exception was that in 1998 the prevalence of overweight in urban areas decreased slightly.
Obesity is a well-known risk factor for several chronic illnesses including type II diabetes, hypertension and scores of cardiovascular diseases. Underweight on the other hand, particularly, among women have direct effect on their health e.g. anaemia and indirectly contributes to maternal and infant mortality. The relative high prevalence of overweight and obesity found among Ghanaian women and the increasing trends observed warrant public health attention. Ghana and many African countries are battling with many existing infectious diseases including malaria, tuberculosis and HIV and AIDS.
Socio-demographic differences in underweight and overweight/obesity by level of education, parity, marital status, wealth index were similar to those found in the Accra Metropolitan area [14]. The increasing prevalence in underweight and overweight/obesity may be explained by the changing nutritional and lifestyle patterns in Ghana. Many African countries have experienced rapid economic growth and development over the past one and half decades. This rapid growth has led to urban lifestyles including changes in food consumption pattern such as consumption of refined food due to the globalisation of the food market [10, 11]. Economic growth, modernisation and globalisation may have also contributed to involvement in more sedentary lifestyles such as motorised lifestyle in Ghana, particularly, in the urban areas. With respect to the association found between wealth index and obesity and overweight, one plausible explanation could be the cultural perception in Ghana, and in Africa in general, which favour large body size [15].
Although in Western countries, overweight is more prevalent among the less educated and those at the lower end on the socioeconomic ladder, in developing countries, a different picture emerged from the literature. Education is positively related to overweight and obesity and the higher a person’s socioeconomic status, the higher the probability of being overweight or obese [12, 13]. The present study confirms this relationship found in developing countries.
Apart from economic growth and modernisation, the contextual meaning of body size might be playing a role in the increasing prevalence of overweight and obesity. In Ghana, cultural values favour large body size [15]. Being fat is often misconstrued as a sign of wealthy living. What is intriguing is the fact that whereas overweight and obesity are increasing, underweight generally remained the same over the period, and among rural women, there has not been any significant change in underweight. This study reveals a double burden of malnutrition that has been reported in other developing countries [5, 6]. With regards to the rural–urban differences, our finding is similar to a recent study from Nepal, which also reported marked differences in the phenomenon among women by rural–urban setting [6]. Several plausible explanations could account for the rural–urban disparities reported here. In the rural areas women mostly engage in agricultural and other activities, which are physical and therefore unlikely to gain as much weight as the urban women. Moreover, women in rural areas are less exposed to western lifestyle and the nutritional transition in the urban areas is not likely to be prevalent in the rural setting. Furthermore, it seems that whereas urban women have more than enough to eat, women in rural have less.
Our study has some strength. Firstly, the data were based on large nationally representative surveys conducted at four time points and the response rate was very good (93 to 96 %) among the eligible women in all four surveys. Therefore, the results are considerably generalizable to the whole country. Secondly, data on the body weight and height were measured by trained study personnel with similar measurement equipment making the data comparable. Thirdly, the surveys used standardized methods comparable to multiple countries. There are also some limitations that are worth discussing. We did not have data on waist circumference which would have allowed examination of trends in abdominal obesity. Additionally, no data were available on behavioural or other factors that could have explained the observed changes in the prevalence of overweight among women.