The global rise in body-mass index (BMI) seen over the last 30 years is largely due to increases in the BMI of rural populations, a Nature paper suggests.
The study challenges the predominant paradigm, which links obesity with urban lifestyles, and could have profound implications for public health policies.
While global obesity rates rise, more and more people are living in cities.
This has led to the view that the urban lifestyle is a major driver of obesity, but the studies supporting this view tend to be small and over short periods of time.
Majid Ezzati and colleagues analysed 2009 studies of more than 112 million adults, which enabled them to assess the changes in BMI that occurred in 200 countries from 1985 to 2017.