When you increase total calories, it can decrease your total protein requirements. If you have a sufficient protein intake (250g is most likely sufficient for him) and you increase it while lowering carbs to an equal amount, then you'll have a similar chance of fat gain. Insulin levels will be potentially lower depending on GI, II, etc but calories are calories. And unless you're doing depletion workouts, quick digesting carbs aren't totally necessary. I know lots of people that do low GI carbs in their PWO shakes. Insulin levels should be sufficiently elevated from a PrWO shake/meal & exercise for nutrient transport. I like the idea of fast digesting carbs in a PWO shake, but it's not altogether necessary.
