[roshanr]

While Fat may not make you fat, all fats are not alike and some fats may be responsible for heart disease and cancer while others may actually be beneficial. This post by Kurt Harris does a good job of explaining why lumping together all fats is not a good idea: http://www.archevore.com/panu-weblog/2011/1/29/there-is-no-s... (PS: Unfortunately, he doesn't cite studies, but with some googling you can find most of the studies).

Obesity itself is a complex topic and blaming it all on carbohydrates seems too simplistic. Over at whole health source, Stephen Guyenet has written a series of articles on the current state of research on insulin resistance - http://wholehealthsource.blogspot.com/2011/11/what-causes-in... Worth a read if you're interested in this topic.