Milk is a good source of protein, with 8 grams in a cup—or about 1 gram of protein per ounce.
This is true whether you choose fat-free, low-fat, lactose-free or whole milk. Each contain high-quality protein, which means they provide all the essential amino acids your body can’t make on its own.
Milk contains two types of protein: casein and whey. Both occur naturally in milk, and the powder form of whey can be mixed in with other foods to boost protein content.
Whey is considered a fast protein because it is digested faster so it releases amino acids to the muscle more quickly than casein does. That might be why so many athletes choose chocolate milk as a recovery drink!
Casein has its place too, however. Some scientists think taking it before bed helps maximize the repair and rebuilding of our muscles as we sleep, because it is digested slower and releases amino acids at a slower rate over time than whey.
No matter when you have it, protein helps bodies rebuild and maintain tissues like those in our muscular and nervous systems. When we get enough protein throughout the day, we likely don’t need to rely much on our body’s stores.
Research shows getting 10 to 15 grams of essential amino acids per meal, including 2 to 3 grams of leucine, which is also found in milk, can help rebuild muscle.
Most Americans meet their daily protein needs, though athletes might require more. If you regularly participate in endurance or resistance exercises, ask a registered dietitian about meeting your protein needs.