Got it. I've heard that theory before but never have I seen any substantial evidence. I accept that the food I eat might have some effect on my "hunger" and "energy level". Which in turn could make me eat more or exercise less. That doesn't really have anything to do with calories per se. Many other causes have the same effect, e.g. psychological or hormonal situations. However, the real argument seems to be that what one eats impacts one's "fat storage or metabolic rates". That's hard to believe. It would be interesting to see some hard evidence to support that claim. The present study tries to give some results, but I think the sample rate is insufficient. I've seen much evidence to the contrary.
The idea that carbohydrates impact fat storage through insulin is one of the main arguments put forward by Taubes in his book, and he provides a lot of evidence and studies to back up his assertion. He may be wrong (and he somewhat acknowledges this and calls for proper studies to be done), but it's worth reading if you want to understand what the argument is.
