They could begin by walking upstairs to their office floors instead of using the elevators. Every European points out that Americans are the most round-shouldered people in the world. Few of them carry themselves with an upright stance, although a correct stance and gait is the first precondition of letting your lungs breathe naturally and deeply. They rush out to jog or otherwise Fonda-ize their leisure to try to repair the damage done during the day. Country dwellers eat what they please, and work it off in useful physical employments, and in the open air, cold or hot, rainy or sunny.
Mailmen are the healthiest city workers.
If one reads the huge menus that formed a normal diet in the 19th century, you realize that even the city dwellers could dispatch these gargantuan repasts because they still shared many of the benefits of rural life. They rode horseback to work or to Parliament even in the coldest weather, and nothing jolts and enlivens the liver more than riding. Homes were cold in the winter, except in the immediate vicinity of the hearth or stove. Cold has a way of eating up excess fat. No wonder dieting is necessary in a cossetted life in which the body is forced to do no natural heavy work.