The fat in the milk is the part that contains vitamins A and D. Stripping the fat from milk also strips the milk of fat-soluable vitamins, which is why “skim and other low-fat mlks are actually required by the government to be fortified with synthetic vitamins to make up for what is lost,” notes Ramos. “Check the label on any container of low or no-fat milk—it will contain Vitamin A-Palmitate and Vitamin D3. These are synthetic versions, which are highly processed, which the body can’t access anyway without the fat. There is also some debate about the potential toxicity and cancer-causing properties of synthetic vitamins.”
Fats also help you feel full longer, by triggering the release of a hormone called cholecystokinin. And they slow the release of sugar into your bloodstream. For both of these reasons, whole milk could actually be better at promoting weight management than low-fat or nonfat milk. A large 2005 study conducted by the Harvard School of Public Health found that, in kids age 9 to 14, skim and 1% milk were linked to weight gain, but whole milk was not.
Of course, there’s still far from a consensus on the whole milk versus skim milk debate. Because so many Americans’ diets are already so high in saturated fat (from fried foods, fast food and excessive meat consumption) and calories, a lot of nutritionists remain wary of recommending a higher-fat, higher-calorie beverage.
“I look at the total diet of an individual and we decide together what (they) can get away with,” says nutrition expert and registered dietitian Lisa DeFazio. She still recommends skim or 1% milk to most of her clients. “If my client REALLY wants 2% milk, then they have to limit other fats at that meal, such as oil on the entree or margarine on their toast. I would not recommend whole milk unless it is for a child 2 years or younger.”