I have used both liquid milk and powdered milk mixed regularly. When I was young, I seldom bought bottled milk.
Yes, powdered milk is mostly skim.
But some years past our food experts came to tell us our bodies make better use of natural foods than man made foods. So, I quickly switched back to butter (now unsalted butter) and plant oils over margarine.
& I've gone to using 2% fat in milk vs.less fat & yes I take cholesterol pills. One has to balance the fat content vs. other additives put in for the milk to have a good shelf life, such as salt.
My periodic test results for my doctor support what I'm doing.
Have you thought of consulting with your family doctor to see what combination would work well for you at your present stage of life?
:C