Food addiction is real. There have been numerous studies published relative to this area. Salt, Fat, and Sugar are three primary substance that people get addicted to. Food establishments, manufactures have mastered integrating these ingredients into any food to create an addiction. Some psychological based research studies were published (dont have on hand at the moment) that showed that addictions to food can be worse than cocaine or herion.
Couple of EXCELLENT books I recommend on this topic!
Mindless Eating: Why We Eat More Than We Think
Brian Wansink Ph.D.
The End of Overeating: Taking Control of the Insatiable American Appetite
Fuel the Movement,