I have extremely educated people that have two opposing beliefs. Until we can counter arguments and use proper reasoning I just have to go with I don't know. Saying it's just less butter isn't enough considering you seem to share the same kind of credibility as Mark. If it was any other time or any other average joe saying this then yeah I would go with your word.
Credibility is the only way for me to decide the right answer, and for someone to be credible I need the sources. Otherwise it's like I said, I don't know.
I will go in a more detailed explanation of what I already discussed before, because I want to make it clear that this discussion is not about "beliefs" or "credibility", neither of those really matter. The facts are what matter, and they are the same for everybody.
Mark simply made an argument by volume, which I feel is too oversimplified, prone to be misinterpreted and actually ultimately flawed as I will explain.
Hopefully if I put some simple numbers to it you can see where the impressions you might have gotten from reading his quote is incorrect at multiple levels, because it blows out of proportion small increases caused by reduction of volume, and more importantly it does not consider aspects of centrifugation that actually reduce carbs in skim milk
This is Mark's argument:
When you remove fat from 1 quart of milk, you remove a small amount of volume. By volume, whole milk has about 3% of fat.
So when you remove it, you have 97% of the original volume of milk, basically you lost 1/30th of the volume of milk.
Here is the critical part: since you still sell it by volume, that 1/30th of liquid is replaced by something. That something is more skim milk. Technically, that does contain also carbs, as well as proteins, vitamins, nutrients, but mostly water (more than 90%).
So, by volume, skim milk has about ~90% of ~3% more water (so ~3% more water), and also ~0.1% more protein and 0.15% more carbs.
So, even considering his point about needing to add 3% more skim milk liquid to preserve equal volumes, the ratio of proteins to carbs is not changed.
Not only that, the amount of calories added by that amount of carbs in a quart of skim milk is at most 2 (TWO) calories compared to the 285 (two HUNDRED eighty five) calories lost from fat, so you don't even come close to "replacing" even just 1% of the calories from fat with carbs, plus again you get more proteins and nutrients too.
Not only that, but in fact more carbs are lost in the separation process than they are 'added' by adding more skim milk volume, so you actually end up with something slightly more protein dense and with slightly less carbs, which makes whole milk have slightly MORE carbs than skim milk, by volume.
If you need more confirmation, you can compare the actual nutritional data of whole milk and skim milk from any source, even by volume as Mark was discussing, for example:
1 quart of
Skim milk: carbs=
50, proteins=
33 calories=333(
link)
1 quart of
Whole milk: carbs=
51, proteins=
31 calories=586 (
link)
