Author: Leigh Breen, PhD, University of Birmingham, United Kingdom
Protein is a part of every cell in your body. It helps to build and repair cells and tissues and it’s important for growth and development, especially during childhood, adolescence, and pregnancy. It’s a major component of skin, muscle, bone, organs, hair and nails. Furthermore, protein plays an important role in many bodily processes, including blood clotting, fluid balance, immune system responses, vision, hormones and enzymes. To keep muscles, bones and tissues healthy, you need to get enough protein every day at every stage of your life.
However, have you ever wondered how much protein you need on a daily basis, or when is the best time to consume it? In this article, I will answer these and more common questions I get regularly about protein. Let’s jump into it!
First of all, what is a complete protein?
Protein is made up of long chains of amino acids. There are 20 amino acids. Nine of these can’t be synthesized by the body, so they have to come from diet. They are the so-called essential amino acids.
Proteins can be either complete or incomplete. Complete proteins are proteins that contain all nine essential amino acids. Animal products like meat, milk, eggs and fish are complete proteins. So are a few plant proteins like soy and quinoa, although most plant proteins are incomplete.
What is leucine and why is it important?
One of the essential amino acids is called leucine. It’s especially interesting for two main reasons: first, leucine is a building block for creating new protein in the body. Second, it’s the molecule that signals to the muscles they need to start the process of remodelling and growth.
Research has shown that an increase in leucine in the blood following protein ingestion is associated with muscle growth responses.
How much protein do we need on a daily basis?
How much protein you need depends on your body weight. For instance, if you weigh around 80 kg, 13 kg of your body mass is protein, which is a substantial amount.
Proteins are constantly created and broken down in the body. That’s why you need dietary protein every day to replace that loss.
The current recommended dietary allowance (RDA) for dietary protein is set at approximately 0.8 grams per kilogram (g/kg) of body mass a day. That’s around 64 grams for an individual weighing 80 kilograms. This is the recommended amount for preventing protein deficiency. However, it may not necessarily be the most appropriate recommendation to maximise health.
What factors affect the amount of protein we need?
How much protein you need depends on factors like your age and activity level.
Studies indicate that people who undertake regular exercise will benefit from a daily protein intake of twice the recommended intake for people in general. That’s approximately 1.6 g/kg body mass. This extra protein is necessary to ensure the recovery and repair of muscle mass and other important functions.
From middle-age, people start losing muscle mass and strength, a condition called sarcopenia. This loss can result in poor physical function, disease risk and premature death. On top of that, the ability to ingest protein declines with age. Therefore, it’s recommended that older people get around 50% more protein than younger people – around 1.2 g/kg body mass.
Older people who exercise should get even more than that – around 1.6-2.0 g/kg per day.
When is the best time to consume protein, and how often should we eat it?
The building of new muscle protein following the ingestion of protein is relatively short-lived and will typically return to normal after a few hours.
In other words, while the total amount of protein you consume during the day is important, most people will get the best effects by spreading their protein intake out evenly over three to four meals a day.
Many athletes take a protein supplement right after exercise. This is not necessarily a bad strategy since muscle is most responsive to dietary protein in the initial few hours after exercise. But since the muscle stays more sensitive to the anabolic actions of protein ingestion for 24-48 hours after training, making sure you get sufficient protein at all meals over the entire day is the most important thing.
How do exercise and protein work together to maintain and build muscle?
Your body is constantly both breaking down and building muscle protein. In most healthy adults these processes will even out to maintain a relatively stable amount of muscle mass.
If you want to increase your muscle mass, exercise is without a doubt the most effective way to achieve this. Training will enhance muscle’s response to protein and thereby muscle growth, so much of the protein you ingest can be used to build new muscle.
What are the benefits of whey protein in particular?
Whey protein is rapidly digested and rich in essential amino acids like leucine that are the important building blocks for skeletal muscle. This makes it highly effective for building or maintaining muscle compared with other protein sources.
Beyond muscle health benefits, the properties of whey protein may also benefit appetite regulation and control blood glucose after a meal. This has important implications for metabolic health and disease prevention throughout your lifetime.
Finally, whey protein contains bioactive peptides. These are effectively sequences of amino acids that are released from milk-derived proteins upon digestion or fermentation, and which may support immune health.
If you want to know more about protein, check out all the interesting content on WheyForLiving.com. From articles to videos, infographics and recipes, you will learn all you need to know about protein and how to implement it in your life.
About the author:
Professor Leigh Breen is an expert in skeletal muscle physiology and metabolism based at the University of Birmingham in the United Kingdom.