Which countries have the most and least active people?

Stanford University has analysed 68 million days' worth of minute-by-minute data from smartphones to determine which countries have the most and least active people. They show that the average number of daily steps was 4,961 across all countries.

Hong Kong citizens were the most active, averaging 6,880 steps a day, while Indonesia was bottom of the rankings with just 3,513.

Most smartphones have a built-in accelerometer that can record steps and the researchers used anonymous data from more than 700,000 people who used the Argus activity monitoring app. 

Scott Delp, a professor of bioengineering and one of the researchers, said: "The study is 1,000 times larger than any previous study on human movement. There have been wonderful health surveys done, but our new study provides data from more countries, many more subjects, and tracks people's activity on an ongoing basis. This opens the door to new ways of doing science at a much larger scale than we have been able to do before."

The findings, published in the journal, Nature, reveal that the average number of steps in a country appears to be less important for obesity levels. The key ingredient was "activity inequality" - the difference between the fittest and laziest. The bigger the activity inequality, the higher the rates of obesity.

Tim Althoff, one of the researchers, said: "For instance, Sweden had one of the smallest gaps between activity rich and activity poor... it also had one of the lowest rates of obesity." The United States of America and Mexico both have similar average steps, but the US has higher activity inequality and higher obesity levels.

In Japan - with low obesity and low inequality - men and women exercised to similar levels. But in countries with high inequality, like America and Saudi Arabia, women spent less time being active.

Jure Leskovec, also part of the research team, said: "When activity inequality is greatest, women's activity is reduced much more dramatically than men's activity, and thus the negative connections to obesity can affect women more greatly."

The Stanford team say the findings help explain global patterns of obesity and give new ideas for tackling it. For example, they rated 69 American cities on the ease to which people walked around their cities. The smartphone data showed that cities like New York and San Francisco were pedestrian friendly and had "high walkability." Houston and Memphis had "low walkability."

http://www.bbc.com/news/health-40570442

MARTINA NICOLLS is an international aid and development consultant, and the author of:- Similar But Different in the Animal Kingdom (2017), The Shortness of Life: A Mongolian Lament (2015), Liberia’s Deadest Ends (2012), Bardot’s Comet (2011), Kashmir on a Knife-Edge (2010) and The Sudan Curse (2009).