Ok, I want to know WHY heavy cream/whipping cream is better than milk.

I know that it is less carbs, I just dont understand WHY it is lower carbs. I have always believed that milk is milk and the only thing different is the fat content. So why are there more carbs in skim/1%/2% milk than the heavier ones?

I was trying to explain this diet to a friend and she asked me this and I was stumped. I am a bit embarrassed that I am spouting information without understanding.

Holly