US researchers have found that obesity is more common in countries where activity levels differ between males and females.
They studied the activity levels of smartphone-users across 46 countries, thanks to the wide usage of a step-counting app.
A big difference between the daily steps taken by males and females was the best sign of a country’s obesity problem, with women more likely to be obese than men.
Activity inequality in Australia was high, with Aussie men taking about 1500 more steps than women daily.
The researchers say say that when cities are more walkable, activity levels are higher for both genders, suggesting that better urban planning could be better for our health.
Determining the disparity of physical activity distribution within a country — coupled with the walkability of its cities — is a better predictor of obesity prevalence in a population than average activity volume, suggests new research published online in Nature.
These findings have implications for global public health policy and urban planning and highlight the effects of activity inequality on physical activity and health.
An understanding of the basic principles governing physical activity is needed to curb the global pandemic of physical inactivity and the 5.3 million deaths per year caused by such inactivity.
Although previous surveillance and population studies have revealed that physical activity levels vary widely between countries, more information is needed about variations in activity levels within countries and how physical activity disparities, health outcomes, and modifiable factors, such as the built environment, are related.
Jure Leskovec and colleagues studied data from 717,527 anonymized users of a step-tracker and calorie-counter smartphone application, and focused their research on 46 countries with at least 1,000 users each.
The authors quantified the activity–obesity relationship at the individual level and found that obesity increases more rapidly in women than men as activity decreases.
For example, the United States and Mexico have a similar number of daily steps, but the US exhibits larger activity inequality and higher obesity prevalence than Mexico.
So, given two countries with identical average activity levels, the country with higher activity inequality will have a greater fraction of low-activity individuals, many of them women, leading to higher obesity for that country than is predicted from average activity levels alone.
The authors also find that in more walkable cities, activity is greater throughout both the day and week — across age, gender and body mass index — with the greatest increases in activity for women.
Source: Stanford University, USA; Chan Zuckerberg Biohub, USA