Is Dairy Good or Bad for You? Milk was once considered an essential part of a healthy diet. Now, more people are skipping it in fear of negative health consequences—but does dairy deserve it? Lactose intolerance affects around 65% of the world's population. Dairy is the leading source of saturated fat in the U.S. diet and contains cholesterol and sodium. However, milk is also high in calcium, vitamin D, and protein. Drinking (or not drinking) dairy is an individual choice. Here are some healthy-dairy tips to help: 1. Pay attention to your body. 2. Choose low-fat, no-sugar-added products. 3. Remember: Liquid calories count too.