Over millennia, evolution designed our bodies to survive scarcity, to get through the lean times by packing on extra pounds as "insurance" against famine. Like the camel's hump storing water in the desert, our bellies and "love handles" store calories to keep us going till the next harvest.
Many of us now face the opposite challenge, trying to survive prolonged abundance. This is a new condition for our species, one for which our evolutionary past does not equip us. Instead our instinctual reaction to plentiful food is to pig out, overeat, store it the only way early man was able - as body fat.
