The following post may explain in part the possibility of food addiction, a highly controversial topic especially when it comes to processed foods.
Perhaps it is best explained by this excerpt from Michael Moss, Salt, Sugar, Fat: How the Food Giants Hooked Us.
” The blood gets especially besieged when processed food is ingested, flooding the system with its heavy loads of salt, sugar, and fat…, there, narcotics and food…act much alike. Once ingested, they race along the same pathways, using the same neurological circuity to reach the brain’s pleasure zones, those areas that reward us with enjoyable feelings for doing the right thing by our bodies. Or, as the case may be, for doing what the brain has been led to believe is the right thing.”
The following link provides us with a video (suggested (13 min.) and the text of a recent TED talk. Interesting analysis.
FOOD, FACTS and FADS 