In Good Calories, Bad Calories and The Primal Blueprint, both authors state that it is impossible to gain weight without carbohydrates because insulin is required. Sorry, I don't have the references at hand. I'm so much healthier eating paleo, but these claims seem unreal. Has anyone tested this? I would love to see a blog of someone eating, say, 3000 calories above maintenance per day and not gaining weight. Maybe I'm misunderstanding and mistcharacterizing their arguments?