Two thousand years ago, the average life expectancy from birth to death of a Roman citizen, an individual better off than most people at that time, was about 22 years (wars, infectious diseases, trauma, etc.). This progressively increased to about 47 years in the U.S. and most European countries by 1900. Today, the average life expectancy in the U.S. is 78 years (women about five years more than men). However, unless the obesity pandemic is reversed and lifestyles improved, the average life expectancy will likely decrease significantly. conversely, if our lifestyles improve, the average life expectancy could reach 85 or more years.

Growing older does not necessarily mean growing sicker. Thus, "don't just add years to your life, add life to your years" (Hans Selve). Indeed, of the 15 major causes of death in the U.S., 65-70% are lifestyle-related. In this book, the following documented topics that are associated with diseases and mortality are discussed in detail: theories of aging; diseases and mortality associated with obesity, physical inactivity and poor nutrition; psychological stress (anxiety, depression); addiction (alcohol, tobacco, drugs); violence (suicide, homicide); food-borne and infectious diseases (viral, bacterial, parasitic); and various other conditions (air pollution, asbestosis, trace metals).