Which modern life style habits lead to disease?

Lack of exercise: The "diseases of modern times" are largely those of old age -- which more of us are reaching. The key health problem that has become worse and made us more sickly is lack of exercise -- this is the major reason behind obesity and the glucose intolerance family. The other habit that I'd cite is rampant self-pity and a sense of entitlement -- we now "medicalize" the normal troubles of life.