Here is a paper from several years ago that goes against "conventional wisdom" arguing that:
...sugary foods contribute minimally to 'food dependence' and increased risk of weight gain. Instead, they are consistent with the current scientific notion that food energy density, and the unique individual experience of eating, plays an important role in determining the reward value of food and promoting excessive energy intake.
I think we need to look at additional studies for conformation or refutation, considering the importance of sugar in the American diet and American obesity. No doubt of course "high food density" is the most important thing and a combination of high fat and sweetness - indeed identified in this study as a problem - may be a particular "villain" here.
