Both milk and protein shakes boast a list of impressive health benefits, including immune-boosting vitamins and minerals, lean muscle mass maintenance or gain and improved physical performance. One isn't an equal substitute for the other, but regularly drinking either beverage may help you achieve certain health or fitness goals.
One cup of skim milk contains about 85 calories, 8 grams of protein, 12 grams of carbohydrates and 300 milligrams of calcium. The same amount of whole milk offers 150 calories, equal amounts of protein and carbs and 275 milligrams of calcium. In comparison, a 32-gram scoop of whey powder has 115 calories, 25 grams of protein, 2 grams of carbs and 150 milligrams of calcium, and the same amount of soy powder has 125 calories, 18 grams of protein, 9 grams of carbs and 55 milligrams of calcium. So, per serving, milk contains about 30 percent to 45 percent as much protein as a scoop of ready-to-mix protein powder. But milk offers more carbohydrates and at least twice as much bone-strengthening calcium.
The Science of Milk
According to the results of a study published in 2007 in the "American Journal of Clinical Nutrition," subjects who drank skim milk after strength training experienced improvement in muscle mass maintenance and gain. Soy protein shakes produced similar improvements, but the study's authors found that milk protein encouraged more rapid effects. In another study, published in 2013 in the journal, "Medicine and Science in Sports and Exercise," participants who drank milk after exercising saw greater gains in their physical performance in a subsequent workout session than subjects who drank a placebo.
The Science of Shakes
Protein shakes have also been scientifically proven to promote muscle protein synthesis and encourage lean muscle mass maintenance and gain, in conjunction with strength exercise. Some are more effective than others, however, and research published in 2009 in the "Journal of Applied Physiology" suggests that milk-based protein shakes made from whey or casein produce greater gains than shakes made with soy. Even in overweight adults who do not exercise, whey protein shakes may encourage lean mass maintenance and body fat loss over time.
Results and Goals
Milk is a healthful, less-processed alternative to protein shakes. Both milk and protein shakes are likely to produce optimal physical improvements if you combine them with a healthy, balanced diet and regular strength exercise, especially if your goal is muscle gain. Before you add a high-protein supplement to your diet, check with your doctor, as most Americans already get more protein than they need.
- USDA: National Nutrient Database
- American Journal of Clinical Nutrition: Consumption of Fluid Skim Milk Promotes Greater Muscle Protein Accretion After Resistance Exercise Than Does Consumption of an Isonitrogenous and Isoenergetic Soy-Protein Beverage
- Medicine and Science in Sports & Exercise: Milk Ingestion Stimulates Net Muscle Protein Synthesis Following Resistance Exercise
- Medicine and Science in Sports and Exercise: Effect of Milk on Team Sport Performance After Exercise-Induced Muscle Damage
- American Journal of Clinical Nutrition: Consumption of Fat-Free Fluid Milk after Resistance Exercise Promotes Greater Lean Mass Accretion Than Does Consumption of Soy or Carbohydrate in Young, Novice, Male Weightlifters
- International Journal of Sports Nutrition and Exercise Metabolism: The Effect of Whey Protein Supplementation With and Without Creatine Monohydrate Combined with Resistance Training on Lean Tissue Mass and Muscle Strength
- The Journal of Nutrition: Whey Protein but Not Soy Protein Supplementation Alters Body Weight and Composition in Free-Living Overweight and Obese Adults
- Journal of Applied Physiology: Ingestion of whey hydrolysate, casein, or soy protein isolate: Effects on Mixed Muscle Protein Synthesis at Rest and Following Resistance Exercise in Young Men
- Physicians Committee for Responsible Medicine: The Protein Myth