If I remember correctly, RP does believe that a calorie is a calorie.
Keeping that in mind; milk and juice are just liquid calories regardless of other nutrient content.

I tend to use whole milk. A quart must be 600. Even reduced fat milk adds up to quite a few cals when you consume_______.

Liquid calories are just easier to absorb since the body doesn't have to chew it's way through fiber.

I don't think I'll ever really enjoy a fully liquid diet.
I've had to endure it on plenty of occasions and was more than ready to chew w/in a few days.

Peat certainly does not do that.