Agreed - there is more than sugar to the story (although I reckon that sugar is a big chunk).
I don´t think it´s all carbs that are a problem though. While people might not want to give up lasagna or bread for any price, I would attribute that more to stuff like the opiate-receptor binding gluten exorphins present in wheat, etc.
People don´t get tuber cravings, they get cravings for grain products, glutamate, sugar, etc.
To make my principles regarding food real simple:
Grains + Sugar + Trans Fats = Avoid.
In addition, I’ve come across some evidence that gluten is implicated in many (if not all?) of the so-called auto-immune problems.
And Rocky...Rush just used your line about Hollywood...I laughed again!