Skim milk has always seemed like the obvious choice, right? It has the same vitamins and nutrients as whole milk, but without all the fat. While that may have been commonplace thinking for a while, recently more and more studies suggest that full-fat milk is a better alternative to the fat-free stuff. In fact, some research suggests people who consume full-fat dairy weigh less and are at lower risk for developing diabetes, too, according to a new study published in the journal Circulation.
Tuft University researchers looked at the blood of 3,333 adults during a 15-year period. Turns out, people who consumed more full-fat dairy products, such as whole milk (marked by higher levels of particular biomarkers in their blood) had a 46 percent lower risk of getting diabetes during the study period than those with lower levels of those biomarkers. While the mechanism of how fat reduces the risk of diabetes is still unclear, the correlation is an important one, and at its simplest, may suggest that full-fat dairy is more filling, so you'll eat less throughout the course of the day, consuming fewer calories overall. (Want more healthy, fatty foods? Try these 11 High-Fat Foods a Healthy Diet Should Always Include.)
Skim milk is also higher on the glycemic index (GI) scale than whole milk by a solid five points, which could explain why it's associated with a greater risk of diabetes risk. GI is a measurement of how fast a carbohydrate breaks down into glucose in the body and therefore how quickly your blood sugar rises or falls. Plus, did you know that consuming skim milk can actually impact your skin, too? A 2007 study published in the American Journal of Clinical Nutrition found that a low-GI diet can help clear up acne, and a high-GI diet may hinder collagen production (collagen keeps you looking young).
Also on board with the high-fat trend is Nitin Kumar, M.D., a Harvard-trained physician who is board-certified in obesity medicine, who says that the most recent study published in Circulation "is in line with others showing a paradoxical effect of dairy fat on diabetes, and related studies that show that dairy fat may be associated with less weight gain," a notable change in direction from the skim-milk proponents of the 80's and 90's.
So with full-fat dairy products doing a body so good, we're wondering why the government's dietary guidelines on MyPlate still suggest low- or fat-free dairy as part of a healthy diet. "The core finding in Circulation study—that dairy fat may prevent the incidence of diabetes—should be confirmed before policy changes are made," says Kumar. "[This] can be used to guide future studies."
We shouldn't expect the government to make sweeping changes based on this small (but growing!) body of research ASAP, but it looks like a push for full-fat dairy is in the cards. "There is a lot of conventional wisdom about weight loss and metabolic disease that is not based on science, and a lot of myths will be dispelled as modern medicine shines a light on how the body handles nutrients and adapts to dietary changes and weight loss," Kumar adds. So while you certainly shouldn't overhaul your diet every time a new study comes out, it's more than fair to say that you can (and should) go ahead and have that mozzarella appetizer and pour whatever kind of milk you want in your next bowl of oatmeal. You can also try in one of these Chocolate Smoothies You Won't Believe Are Healthy.