Protein

What is protein?

Protein is an essential macronutrient made from amino acids. Protein powders provide concentrated protein from sources such as milk, soy, peas and other plants.

What does protein support?

Protein contributes to the growth and maintenance of muscle mass and helps maintain normal bones.

Amino acids and leucine

Proteins are made from amino acids. Nine are considered essential amino acids (EAAs) because the body cannot make enough of them itself. Leucine is one of the branched-chain amino acids (BCAAs) and is particularly relevant to muscle-protein synthesis.

Some protein powders publish a full amino-acid profile, but many do not. For ordinary product comparison, protein source and total protein per serving are usually more consistently available than a detailed amino-acid table.

BCAAs are leucine, isoleucine and valine. They are already present in complete proteins such as whey and soy. A separate BCAA addition does not replace a full source of essential amino acids; compare the complete protein content before focusing on added BCAAs.

How much protein do you need?

Protein needs vary with body weight, age, activity and goals. For generally healthy adults, a commonly used reference intake is 0.83 g per kg of body weight per day. For a 75 kg adult, that is approximately 62 g per day.

People doing regular resistance training may benefit from higher intakes. Around 1.4–2.0 g/kg/day is a commonly discussed sports-nutrition range, equivalent to approximately 105–150 g/day for a 75 kg person. This is context for total daily intake, not a target everyone needs to reach.

“Source of protein” vs “high protein”

Source of protein requires at least 12% of the food's energy value to be provided by protein; high protein requires at least 20%.

Whey concentrate vs whey isolate

Both come from milk. Isolate is more highly refined and generally has a higher protein proportion with less accompanying fat and carbohydrate, but exact nutrition varies by product and flavour.

Plant protein powders

Common sources include soy, pea, rice, pumpkin seed and blends. Soy is a complete protein containing all essential amino acids. Other plant proteins can differ more in their amino-acid profile, which is one reason products sometimes combine several sources.

What about casein?

Casein is another milk protein, alongside whey. It digests more slowly than whey and is commonly sold as micellar casein powder. Both provide essential amino acids; the main practical differences are texture, digestion rate and how you prefer to use the product.

Casein often makes a thicker shake or pudding. Choose between whey and casein based on your overall protein intake, taste, dietary needs and convenience rather than assuming that one is always better.

Protein per serving vs per 100 g

Per serving shows what the labelled scoop provides. Per 100 g helps compare protein concentration when scoop sizes differ.

For example, 24 g protein in a 30 g serving equals 80 g protein per 100 g. Compare both figures to avoid mistaking a larger scoop for a more concentrated powder.

What else is in a protein powder?

Protein powders often contain more than the protein source itself. Depending on the product, the label may include flavourings, sweeteners, thickeners or emulsifiers. Some formulas also add ingredients such as creatine, free amino acids or BCAAs, digestive enzymes, vitamins or minerals.

Added ingredients are not automatically an advantage. Check what is present, how much is supplied and whether it is relevant to what you actually want from the product.

For example, some powders include creatine. Check its stated amount per serving rather than assuming that a protein-and-creatine blend supplies the same amount as a dedicated creatine product.

What should you compare?