Global obesity rising faster in rural areas than cities, study finds

The global rise in body-mass index (BMI) seen over the last 30 years is due largely to increases in the BMI of rural populations, a study of 33 years of trends suggests.

Commonly held perception that obesity is a city problem could now be overturned

Female members of the "Danza Voluminosa" Ballet (Voluminous Dance) practise in their studio in Havana in 2000. Researchers say there have been 'striking changes' in the geography of obesity worldwide. (Jorge Silva/Reuters)

Global rates of obesity among people who live in the countryside are rising faster than those among city dwellers, in part due to greater access in urban areas to healthier foods and places to exercise, researchers said on Wednesday.

In a study of 33 years of trends in body mass index (BMI) across 200 countries and territories, the scientists found that people worldwide are getting heavier — with average weight rising by five to six kilograms (11 to 13 pounds) over the period of the study — and that most of the rise is due to gains in BMI in rural areas.

"The results of this massive global study overturn commonly held perceptions that more people living in cities is the main cause of the global rise in obesity," said Majid Ezzati, a professor at Imperial College London who co-led the work.

He said the findings showed "that we need to rethink how we tackle this global health problem."

The study, published in the journal Nature on Wednesday, analyzed height and weight data from around 112 million adults across urban and rural areas of 200 countries and territories between 1985 and 2017.

BMI is an internationally recognized scale that gives an indication of whether someone is a healthy weight. BMI is calculated by dividing a person's weight in kilograms by their height in metres squared, and a BMI of between 19 to 25 is considered healthy.

The study found that between 1985 and 2017, average rural BMI increased by 2.1 in women and men. In cities, however, the gain was 1.3 and 1.6 in women and men, respectively.

In most parts of the world, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. (VGstockstudio/Shutterstock)

The researchers described "striking changes" in the geography of BMI. In 1985, urban men and women in more than three quarters of the countries studied had higher BMIs than their rural counterparts. But 30 years later, the BMI gap between urban and rural dwellers in many countries had shrunk dramatically, or even reversed.

This may be due to some disadvantages for people living in the countryside, the researchers said, including lower levels of income and education, limited availability and higher costs of healthy foods, and fewer sports facilities.

Ezzati said that while discussions about public health often focus on negative aspects of city living, these findings show there are some benefits.

"Cities provide a wealth of opportunities for better nutrition, more physical exercise and recreation, and overall improved health," he said. "These things are often harder to find in rural areas."

The proportion of overweight and obese adults in the rural parts of many low- and middle-income countries is also rising more quickly than in cites.

"Rural areas in these countries have begun to resemble urban areas," Barry Popkin, an expert on global public health at the University of North Carolina, said in a journal commentary.

"Modern food supply is now available in combination with cheap, mechanized devices for farming and transport," he said. "Ultra-processed foods are also becoming part of the diets of poor people."

With files from CBC News