How Whey Protein Works in Your Body

Whey protein is a combination of proteins that are separated from whey—the liquid part of milk that is a remnant during the production of cheese. Whey is the protein present in the watery portion of the milk. Milk contains two types of proteins: casein (80%) and whey (20%). When we open a yogurt or curd container and see some liquid floating on the top, that is whey. The whey liquid that is separated during cheese production goes through various processing steps to become a whey protein supplement—a protein powder used to make shakes, protein bars, or meal replacements.

Whey protein does not have an appealing taste on its own and hence is flavored. It’s important to read the ingredient list before buying it, as it may contain unhealthy additives like added sugars and flavors. Whey protein is known to help build muscles, maintain existing muscles, and is a great source of energy due to its high content of BCAAs (branched-chain amino acids). Out of the three BCAAs (leucine, isoleucine, and valine), leucine is particularly important as it stimulates muscle protein synthesis. Whey protein is loaded with leucine—a 25-gram scoop of whey protein contains approximately 3 grams of leucine, while casein contains only 2.3 grams and soy has only 1.5 grams.

Is Whey Really Necessary?

Throughout the day, all 20 amino acids should be made available to the body through the bloodstream. If the body does not get an adequate amount of amino acids, it will break down muscle stores and other tissues to obtain them for life-sustaining functions, which is known as catabolic functions. Consumption of protein is a simple and easy way to get all the essential amino acids required by the body. According to the Indian Council of Medical Research (ICMR), the protein requirement for a sedentary adult is around 0.8-1 g/kg body weight, while for people who wish to develop or gain muscles it is 1.2-1.7 g/kg body weight. Professional athletes who perform intense training may require 1.7-1.8 g/kg body weight of protein. A recent survey mentioned that 93% of Indians do not know about their protein requirements and are unable to meet them through natural food sources. Consuming protein is essential for everyone to bridge the gap between requirement and deficiency, but it should be used as a supplement and not as a replacement. Whey protein is one of the fastest-absorbing proteins, constituting about 80% of the milk protein and having the best bioavailability compared to other protein sources.

What Are the Benefits of Whey Protein?

Proteins are the building blocks of our body and are used for the production and wear and tear of tendons, organs, skin, hormones, enzymes, neurotransmitters, and various other molecules. Proteins also play an important role in building the contractile elements in the muscles. Whey protein helps to boost protein and BCAA intake. Our body produces some amino acids, while others are supplied through the foods we eat. The amino acids obtained from food are known as essential amino acids. Whey protein is loaded with all nine essential amino acids and contains a high amount of branched-chain amino acids (BCAAs), particularly leucine, and is also rich in cysteine. Studies indicate that leucine is the most growth-promoting (anabolic) amino acid, while cysteine helps to boost glutathione levels—a key cellular antioxidant. Whey protein is also effective in stimulating growth in humans, with human breast milk consisting of 60% whey compared to just 20% in cow's milk.

Effects of Whey Supplementation on Muscle Mass and Strength

Whey protein supplements are commonly consumed to increase muscle mass and strength. They are part of the daily diet of athletes, bodybuilders, fitness models, and individuals seeking to improve their strength and endurance. Whey protein helps to gain muscle and strength by:

  • Building Blocks: Whey protein serves as building blocks for muscle growth by providing essential protein and amino acids.

  • Hormones: It stimulates the production of anabolic hormones like insulin, which help enhance muscle growth.

  • Leucine: Whey protein is rich in the amino acid leucine, which stimulates muscle protein synthesis at the genetic and molecular levels.

  • Fast Absorption: Compared to other types of proteins, whey protein is absorbed and utilized quickly within the body.

According to a recent study, total daily protein intake is the most important factor in promoting muscle growth, regardless of when it is consumed. It is also crucial to understand that whey protein should supplement and not replace food, bridging the gap between requirement and deficiency.

Other Health Benefits of Whey Protein

As discussed, whey protein is a superior source of quality protein. Here are a few reasons why it should be part of your daily routine:

  1. Increases Muscle Mass: Whey protein contains all essential amino acids, including branched-chain amino acids, with leucine being the most important. Leucine fuels muscle cells and increases protein uptake by muscles, working best in conjunction with weight and strength training.

  2. Improves Metabolism: Whey protein supplements can promote fat loss while preserving lean muscle mass. A study observed that individuals consuming whey protein lost significant weight compared to those who didn’t. It aids in calorie burning and prevents metabolic slowdown.

  3. Helps Regulate Blood Pressure Levels: Whey protein contains lactokinins—ACE inhibitors that positively affect blood pressure regulation. Therefore, whey protein consumption reduces the risk of heart disease or stroke.

  4. Antioxidant and Immune Properties: Whey protein is rich in essential and non-essential amino acids and helps produce glutathione—an important antioxidant for the body. The amino acids cysteine, glutamate, and glycine are required for glutathione production. Regular whey consumption boosts the body's antioxidant capacity and immune response, helping combat free radical damage.

  5. Helps Regulate Cholesterol Levels: Studies suggest that overweight individuals who regularly consumed whey protein showed a decrease in total cholesterol and LDL levels compared to those who consumed casein.

Dosage and Side Effects

Whey protein is convenient and easy to integrate into your daily routine. It typically comes in powder form and can be added to smoothies, yogurts, or simply consumed with water. A safe recommended dose of whey protein is 25-50 grams per day (1-2 scoops). Excessive protein intake is not beneficial. It should supplement food sources to meet daily protein requirements and avoid deficiencies. Overconsumption of whey protein can disrupt the digestive system and lead to symptoms such as:

  • Nausea
  • Pain
  • Bloating
  • Constipation or diarrhea
  • Flatulence
  • Abdominal cramps

Individuals who are lactose intolerant should opt for whey protein hydrolysate or isolate rather than concentrate. If you have underlying health conditions, it's wise to consult a doctor before taking any protein supplements.

Conclusion

Whey protein offers a convenient way to increase protein intake and avoid deficiencies. It is a superior protein source that is efficiently absorbed and utilized by the human body. Meeting the body's protein requirement is essential for everyone, especially for athletes, bodybuilders, or individuals looking to gain muscle. Before consuming any protein supplement, consult a qualified dietitian to determine your specific requirements and how to meet them. Do not begin protein supplementation without proper consultation.