Urban-rural disparities in obesity levels: a global trends analysis

Urbanisation is one of the major demographic shifts characterising the last century. Current estimates of the global population living in cities are at 54%. Certain health outcomes such as infant mortality and life expectancy... [ view full abstract ]

Urbanisation is one of the major demographic shifts characterising the last century. Current estimates of the global population living in cities are at 54%. Certain health outcomes such as infant mortality and life expectancy provide evidence of an urban health advantage. Although urban lifestyles are frequently typified by behavioural risk factors for noncommunicable diseases (NCDs), empirical evidence for the impact of urban living on these leading causes of global mortality remains ambiguous. Previous studies include data from a single time-point or location and the comparability of results is further limited by their use of different approaches to classify urban settlements. This study quantifies the prevalence of obesity, an established risk factor for multiple cancers and cardiovascular diseases, in urban and rural populations of countries worldwide and trends over recent decades.

Population-based surveys that measured participants’ height and weight using standardised protocol were systematically collated. A Bayesian hierarchical model was used to estimate the prevalence of obesity (body mass index ≥30 kg/m2) by urban and rural place of residence in the adult population of 200 countries and territories, for each year between 1985 and 2014.

Data from 1608 studies, involving 18.3 million participants, were pooled for analysis. Preliminary investigations confirm the upward trend of obesity levels globally with the levels highest in Oceania. Obesity is more prevalent among urban than rural residents of Latin and America and the Caribbean, North and Sub-Saharan Africa, Central Asia and the Middle East, particularly in women aged 40-59. The same is seen in women over 60 in Central and Eastern Europe, with the opposite in younger-ages. In other regions, urban-rural differences are less apparent.

These comparable estimates of obesity levels in urban and rural populations worldwide provide an important resource for investigating the contribution of urban living towards this major public health problem.