Is Skim Milk Making You Fat?

You probably spend all of one second deciding what kind of milk to put in your coffee. What's to debate? If you want to keep the pounds off and avoid heart disease, choose skim. This is gospel, after all: It's recommended by the USDA and has so permeated our thinking that you can't even find reduced-fat (2%) milk at places like Subway—and forget about whole.

But is it true? Let's start with the question of what's fattening. Whole milk contains more calories and, obviously, more fat. A cup has 146 calories and almost 8 grams of fat, reduced-fat (2%) has 122 calories and almost 5 grams of fat, low-fat (1%) has 103 calories and 2.5 grams of fat, and nonfat (skim) has 83 calories and virtually no fat.

But when it comes to losing weight, restricting calories has a poor track record. Evidence gleaned from numerous scientific studies says that if you starve yourself for lunch, you typically compensate at dinner. And according to a 2007 report in the Archives of Internal Medicine, telling overweight and obese patients to cut calories led to only "transient" weight loss—it didn't stay off.

The same goes for cutting saturated fat. In 2003, the Cochrane Collaboration, a respected source for unbiased reviews of research, compared low-fat diets with low-calorie diets and found that "fat-restricted diets are no better than calorie-restricted diets in achieving long-term weight loss." As Walt Willet of the Harvard School of Public Health wrote in the American Journal of Medicine, "Diets high in fat do not appear to be the primary cause of the high prevalence of excess body fat in our society, and reductions in fat will not be a solution."