Skimmed milk
Skimmed milk (United Kingdom and Canada), or skim milk (United States of America, Australia, and Canada), is made when all the cream (also called milkfat) is removed from whole milk.
Background
Historically, skimmed milk was used for fattening pigs, and was recommended as "not only the very best supplement for growing pigs, but is of almost equal value for fattening purposes" as it "furnishes a complete protein" and makes the feed "more palatable."
It is thought that the reduction in calories keeps the body further from satiety, causing it to ultimately seek out the same amount of calories that would have otherwise been consumed, and in some cases possibly more or from sources less beneficial. The extent to which animal fat contributes to weight gain is also brought into question, along with claims that skimmed milk is more beneficial to heart health since non-skimmed milk has a higher low-density lipoprotein content. Milkfat, however, affects only large, non-dense (Pattern A) LDL particles, which studies have shown to carry far less risk of coronary heart disease than small, dense (Pattern B) LDL particles. Skimmed milk also contains almost no Vitamin A.