I've written elsewhere in this blog about the sensory aspects of addiction, so I won't dig all of that up. What I will say is that, as we discover more, it becomes apparent that the sensory processes of the human person have sadly been routinely confused with psychology.
Here's an example of inroads into the sensory process, this time the Yale University study entitled Which Foods May Be Addictive? The Roles of Processing, Fat Content, and Glycemic Load.
Here's the Abstract:
We propose that highly processed foods share pharmacokinetic properties (e.g. concentrated dose, rapid rate of absorption) with drugs of abuse, due to the addition of fat and/or refined carbohydrates and the rapid rate the refined carbohydrates are absorbed into the system, indicated by glycemic load (GL). The current study provides preliminary evidence for the foods and food attributes implicated in addictive-like eating.
How do we fight our own nature, then? Well, the truth is that addiction is complex, and has as much to do with context as it does with the nature of the substance. Plenty of people try cocaine or heroin and never develop addiction.
We can't just blame the substance, though we ought to understand why the substance works.