Milk may have been adjusted by separating part of the milk fat therefrom, or by adding thereto cream, dry whole milk, skim milk, or nonfat dry milk.

FORBES: Why Milk Isn't As "Natural" As You Think

The fact that whole milk drinkers may still end up weighing less than skim milk drinkers despite the added calories from fat actually does make some sense, however.

CNN: Drinking skim milk may not lower child obesity risk

"So the ones drinking skim were by far the heaviest, and those drinking whole milk were the lightest, " he says.

CNN: Drinking skim milk may not lower child obesity risk