There is a difference between being hungry and having an irresistable desire for some specific food such as sweet, sugary foods or chocolate. There is evidence that food cravings and addictions activate some of the same areas in the brain. The more we give in to these cravings and the lure of sugary treats, the more we get addicted to the sweet taste and the temporary spike of energy it provides.
It is important to realize that after an hour or two the cycle begins again and the drop in blood sugar has you reachiong for more of the same foods. And just like an alcoholics addiction to alcohol, the urge to consume more sugar is hard to resist.
The average consumption of sugar has increased steadly over the last century and it is estimated the be in the 150 to 170 pound range per adult annually in the developed countries such as North America and the least affected areas being Asia and Africa.