While they could be eating triggering foods, I simply believe genetic difference causes some people to like certain foods while others like other foods. The reaosn I think this is so, is because even when I was eating high carb, I simply did not crave most carbs. Let me explain. Say you gave me the choice between two meals, and I could eat either meal and not have it affect me differently from the other.

meal a:
A juicy steak with garlic onions and mushrooms, some spinach/broccoli sauteed in garlic, olive oil and lemon juice as a side. For desert there will be rich cheesecake topped with berries and whipped cream, with a crumbly/textured nut crust.
meal b:
A bowl of pasta and sweet/savory herb sauce, with a crusty slice of garlic herb italian bread as a side. For desert there will be soft warm chocolate chip cookies.

Even before atkins, I would without hesitation choose meal a. No doubt I would enjoy meal b as well, but I actually crave the heavy, rich, textured, fattiness of meal a. I always fancied in foods the qualities of heaviness, richness, interesting "weighty" textures, as well as pungent/salty/savory/sour flavors. I simply did not crave light sweet things that much.

I do entirely believe this is a genetic difference. There are 6 flavors that are interpreted by the tongue, and everyone has a different concentration of taste buds to perceive these flavors. Meaning, the way one thing tastes to me or you might not taste the same way to someone else. So what I am saying is, while you or I may not crave non-atkins food, some poor people might have the genetic hard wiring to like those foods. It must be much harder for these people to stay on LC.