The Diseases Of Civilization
From Medical News Today, a concise explanation as to why excess food and inactivity are very bad for our healthy and life span. "Human beings are genetically adapted to conditions of scanty and irregular nutrition. In case of food abundance this advantage turned into a significant part of population's predisposition to 'diseases of civilization'. ... During the era of civilization, the major part of mankind passed to abundant nutrition without starvation periods which were quite natural previously and without significant spending of muscular energy." This change in usage of the complex biochemical machinery of our bodies leads to common age-related disease, suffering and shortened life spans. Fortunately, all of this is within our ability to control - exercise, supplementation and calorie restriction are your friends.
Link: http://www.medicalnewstoday.com/medicalnews.php?newsid=29755