Was there a time when you walked to work and was that before fast food ? Without excercise for fitness and proper diet for thinness, people become fat, as you very well know. The graph from US Today, 8 May 2001 shows a radical change in life style regarding transportation. Nearly everybody goes by car, whereas we used to get much more excercise. When most people cannot afford a car, buses are frequent. The overuse of cars that incidentally pollute the air is a cause of obesity.