Obesity is increasing faster in rural areas than in urban areas

Extensive international research reveals an interesting phenomenon in the increasing obesity among world population: the geography of body-mass index (BMI) appears to have changed radically over the last few decades. In 1985, urban men and women in the majority of the countries had a higher BMI than their rural counterparts. However, in approximately 30 years, the situation has practically been reversed.

A study led by Imperial College London analysed the height and weight data of more than 112 million adults from 200 countries between 1985 and 2017.

During this period, the average BMI in rural areas increased by 2.1 kg/m2 in both women and men, whereas in cities, the increase was 1.3 kg/m2 and 1.6 kg/m2 in women and men respectively.

Globally, the BMI increased by an average of 2.0 kg/m2 in women and 2.2 kg/m2 in men, equivalent to each person becoming 5–6 kg heavier.

More than half of the global rise over these 33 years was due to increases in BMI in rural areas. In some low and medium income countries, rural areas accounted for more than 80% of the increase in the BMI.

The results of this study overturn the previous perception that more people living in cities is the main cause of global increases in obesity.

In public health debate, urbanisation and living in cities have almost exclusively been seen as a negative issue. The research group emphasises that cities offer plenty of opportunities for exercise and leisure activities, healthy food and health maintenance, whereas in rural areas, the income and education levels are lower, healthy food is more expensive and limited in supply, and there are fewer exercise facilities available.

In many countries, the income level in rural areas has increased, agriculture has become more mechanised and the use of cars has grown, which, in turn, have reduced the amount of physical activity. Food is accessible and people have money to buy it, but it is often of poor quality and fattening.

 

Small differences between rural and urban living areas in Finland

The study also utilised Finnish population data, such as the Northern Finland Birth Cohort of 1966, Oulu35 and Oulu45 material of the University of Oulu, including the data of approximately 15,000 people born in Northern Finland.

In Finnish studies, regional differences in BMI have been observed, and obesity is more common in rural areas.

“We have observed that obesity and BMI increase when moving farther away from municipal centres and, on the other hand, as population density decreases. People also regard their health to be poorer in more sparsely populated areas further away from the cities”, says Post-doctoral Researcher Tiina Lankila from the University of Oulu, who has utilised cohort 1966 in her research.

Social and lifestyle factors have been presented as explanatory factors. In rural areas, the distances are long, which makes it difficult to combine physical activity with other everyday activities. According to Lankila, the viewpoints of exercise and health should be taken into account in the planning of rural areas.

In Finland, obesity has continued to grow slightly more among city residents than rural residents. Here, the differences between rural and urban living areas may be small compared to several other countries in the study. In Finland, nature and rural environments are within easy reach of urban residents, and the areas are well mixed.

Unique in its scope, the study was published in Nature.

The research was carried out by an exceptionally large number of experts worldwide. Participating researchers from the University of Oulu include Docent Juha Auvinen, Professor Raija Korpelainen, Doctoral Student Soile Puhakka, University Researcher Sylvain Sebert and Professor Marjo-Riitta Järvelin, who also works as professor at Imperial College London.

 

Further information: 

Juha Auvinen, Docent, MD, PhD
Center For Life Course Health Research (CLCHR)
University of Oulu
juha.auvinen@oulu.fi
Tel. +358 40 480 5540

Raija Korpelainen, Professor of Health Exercise
Center For Life Course Health Research (CLCHR)
University of Oulu
Oulu Deaconess Institute (ODL), Department of Sports and Exercise Medicine
raija.korpelainen@odl.fi
Tel. +358 50 312 5746

Tiina Lankila
Post-doctoral Researcher
Research group of Geography
University of Oulu
tiina.lankila@oulu.fi
Tel. +358 50 524 0575

 

Article: NCD Risk Factor Collaboration (NCD-RisC). Rising rural body-mass index is the main driver of the global obesity epidemic in adults. Nature. May 8 2019.

More information in NCD-RisC webpages: http://www.ncdrisc.org/

 

 

 

 

Last updated: 8.5.2019