Human activities strongly influence a population's states of health and disease. For example, an energy-rich food supply combined with a plethora of energy saving devices, from cars to TV lounges, appears to be responsible for much of the increase in obesity which affluent societies have experienced in the past half century.
According to the World Health Organization 70 to 80% of all deaths in the industrialized world and 40 to 50% in developing countries are so-called "affluent society" diseases, attributable to high blood pressure, heart attack, stroke or lung cancer. These diseases are caused by unhealthy diet, lack of exercise and smoking.