John Pucher of Rutgers University combined the data on the link between exercise and obesity from 14 countries and all American states, including a number of large cities. Among these a Chinese study tracking 67,000 women over a five-year period. In that group comparatively fewer women died who cycled and walked regularly. Studies in Denmark clearly point in the same direction as well. Cycling to work decreases the mortality rate by 40 per cent. And studies from Odense report that a 20 per cent rise in the cycling share over a period of six years increases life expectancy (in this case for men) by 5 months. And according to Pucher it can be stated that the number of people with obesity is lower in European countries with high percentages of cycling in comparison to Australia and the United States.
The diagram shows a survey of a number of studies finding a link between transportation behaviour and obesity, on the basis of self-reported behaviour or clinically obtained data.