 One of the causes most prevalent in the developing world is urbanization. As more of the population moves to cities, population over-crowding, increased poverty, increased levels of crime, high-density traffic, low air quality and lack of parks, sidewalks and recreational sports facilities leads to a less active lifestyle. Another cause in the case of children is that physical activity in activities from self-propelled transport, to school physical education, and organized sports is declining in many countries.
400px|United Kingdom transport modal share from 1952 to 2014, Department for Transport One of the causes most prevalent in the developing world is urbanization. As more of the population moves to cities, population over-crowding, increased poverty, increased levels of crime, high-volumes of car traffic, low air quality and lack of parks, sidewalks and recreational sports facilities leads to a less active lifestyle. Another cause in the case of children is that physical activity in activities from self-propelled student transport, physical education, and organized sports is declining in many countries.
A
400px|United Kingdom transport modal share from 1952 to 2014, Department for Transport
R
high-density
high-volumes of car
R
transport, to school
student transport,