There's an interesting concept in insulin action that I think add to the notion that a calorie is NOT just any calorie. That would be specially important in the metabolically sick people, aka people with metabolic syndrome, hyperinsulinemic, trying to lose weight. Have you read about SELECTIVE insulin resistance?

That means that after insulin binds to its receptor, there are more than one pathway to follow and they stimulate very different actions. Unfortunately for us in abundant food times, some of them are lost as we get resistant.