It seems obvious: Swapping skim milk for 2% or whole milk is the healthy decision. After all, skim milk contains the same nutrients as the full-fat stuff, but with less calories and less fat. But the diet dairy choice might not be as good for you as was once thought. In fact, a number of nutritionists, researchers and health experts have begun making the case that whole milk is the most nutritious dairy milk option.
It wasn’t until the 1950s that milk started being sold with varying fat levels (before that, whole milk was just plain ‘milk’). Ditching whole milk for lower-fat varieties has since become dietary gospel in the United States, preached by the likes of the federal government and the American Heart Association. One cup of whole milk has about 150 calories, 8 grams of fat and 4.5 grams of saturated fat. A cup of skim (a.k.a. ‘nonfat’) milk has just 80 calories and less than half a gram of fat.
The disparities do make skim milk a healthier choice for certain groups of people—those whose diets are already high in saturated fat; those who consume copious amounts of milk (those calories and fat grams add up). But for your average milk drinker, whole milk (or 2%) has surprisingly more to recommend it than its nonfat or low-fat rivals. Here are three reasons why you may want to rethink skim milk.
1. Whole milk is better for fertility. A 2007 study found low-fat dairy foods could increase a woman’s infertility risk, by affecting ovulatory function. But high-fat dairy foods were shown to decrease infertility risk.
2. Skim milk could promote heart disease. Skim milk is made by separating and removing the fat content from whole milk. This leaves the milk a blueish-gray color, and also may decrease its protein content. To boost protein and whiteness, then, it’s common for milk producers to add milk powder to nonfat (and possibly 1% and 2%) milk, via a process that subjects the milk to high temperatures and pressure. This process also causes skim milk’s cholesterol to oxidize. Oxidized cholesterol is carcinogenic, and has been shown (in animals studies, at least) to promote plaque formation in arteries and heart disease. Meanwhile, there’s little evidence that a low-fat diet, in and of itself, can actually prevent heart disease. As researcher Frank B. Hu puts it, writing in the Journal of the American College of Nutrition:
During the past several decades, reduction in fat intake has been the main focus of national dietary recommendations. In the public’s mind, the words “dietary fat” have become synonymous with obesity and heart disease, whereas the words “low-fat” and “fat-free” have been synonymous with heart health. It is now increasingly recognized that the low-fat campaign has been based on little scientific evidence and may have caused unintended health consequences.”
3. Fat—even saturated fat—can be good for you. The fat in whole milk is mostly saturated fat, which isn’t the kind you want a ton of in your diet. But some saturated fat in the diet—up to 20 grams per day, according to nutritional guidelines—is okay, and even beneficial. “Our bodies require fat (like the saturated kind found in whole milk) to help us create cell membranes and important hormones,” says nutritional therapist Margaux Rathbun. “We also need fat for energy storage and the padding of the organs inside our bodies.”
“Fear of fat is such a common misconception,” agrees chef and cooking instructor Alejandra Ramos. “Our bodies can’t properly use the protein, calcium and vitamins in milk without the fat.”