How much protein can you absorb at once?

When it comes to diet, understanding nutrition is about more than just knowing your way around the food pyramid.

After all, how your body unpacks, stores, and utilises all of the minerals, vitamins and nutrients it needs to keep you happy and healthy is no uniform task. Processing protein can be a particularly crucial factor to understand as this macronutrient is responsible for most of the work that keeps your body functioning on a day-to-day basis [1].

Not only do proteins help your body fight disease, digest food, and send messages between your vital organs, but they also provide the structure and support for your muscle tissue, strengthening your body and helping you to build the lean muscle mass that keeps you feeling your best [1].

In that sense, it can be normal to think of protein as the sort of fuel we could never get enough of, but the truth is that there is a limit to how much protein your body needs, and similarly, there are times when you can take it to ensure your body gets the best possible use out of it.

But how much protein is ideal for you? How risky is a high-protein diet? And when should you eat protein to maximise muscle growth? To understand the answers to these questions, we first need to understand how our body utilises protein.  

What happens when you consume protein?

Proteins are made up of a linked combination of constituent amino acids.

There are roughly 20 different types of amino acids, and the different combinations of them are utilised by your body in different ways to build muscle and bone, enzymes and hormones, which can in turn be used in a range of ways for your body’s functioning.

Of these amino acids, 11 can be made by your body, but 9 can only be gained through protein consumption. These are known as essential amino acids and are vital nutrients for all human function [2].

Whether you’re getting your protein from eggs, meat or a protein shake, your body starts to break down and process protein from the moment you start chewing on it.

The enzymes in your saliva start this process, which continues in your stomach through to your small intestine. It’s here that the protein — now a series of amino acids — is absorbed through your intestinal wall and enters your bloodstream. It is then taken to cells across your body with the task of repairing damaged tissue and building muscle in a process called skeletal muscle protein synthesis [3].

Does protein distribution matter for weight loss?

Increasingly, nutritionists and researchers are exploring the possibility that daily protein intake is a less useful measurement than individual meal requirements for protein. This area of thought is known as protein distribution and has become a particular focus of those increasing protein intake to lose weight or gain muscle mass [4].

The idea is that you can better stimulate the process of muscle protein synthesis by distributing your protein consumption evenly across the day instead of having a lot of protein for one meal, and then less in others.

By eating a lot of protein in one meal, research has found that ‘excess’ amino acids can be oxidised, which results in your body failing to utilise them. Having less protein in any one meal, but eating that same amount of protein overall through distributing it across the day can reduce amino acid oxidation and maximise their contribution towards muscle protein synthesis in a way that creates optimal muscle growth [4].

Given how new this area of study is, at this stage, there’s no conclusive evidence to show that protein distribution has a real impact over focusing on your daily intake; however, some early research is showing promising signs. It certainly sounds like it could be a space to watch!

How much protein can your body absorb in one meal?

The question of how much protein your body can absorb in one meal can be a bit of a trap.

After all, as one study notes, the term ‘absorption’ is typically defined in digestive terms as the passage of nutrients from the gut into the systemic circulation, and in that sense, the amount of protein that can be absorbed in a meal is pretty much unlimited [3].

Of course, that doesn’t necessarily mean your body can use all of it, and consuming too much protein can create serious health risks in other areas of your body, straining the kidneys and liver [2], and can even lead to heart disease and colon cancer [6].

Like with many things when it comes to diet, the key to a healthy amount of protein is moderation.

One study in particular found that the ideal amount of protein per meal for muscle protein synthesis is between 20-25 grams [3], which on average, seems to be correct. That said, as many studies have noted, numerous factors can come into play, rendering the idea of a perfect amount a little more complex than it initially appears.

After all, the composition of a protein source, along with a person’s protein metabolism, age, weight and lifestyle, can all affect the way their body processes protein and absorbs amino acids and can have a significant impact on muscle growth and repair.

As a result, working out your protein needs with a nutritionist or tailored program such as Juniper’s Weight Reset Program can help you not just stay on track, but adjust your diet based on your changing body’s needs.

Animal vs plant-based protein: Which one is easier to absorb?

The debate over whether animal or plant-based proteins are best is a hotly contested one, and a 2023 study conducted by Purdue University was the latest to put the two protein sources to the test.

What they discovered backs up what many other studies have found which is that animal-based protein such as that found in meat or animal products like eggs and whey protein tends to be easier for the body to absorb, and leads to greater muscle growth and a healthier, functioning body composition [5].  

If you want to incorporate more animal-based protein into your diet, Juniper's Nourish Shakes are an excellent option. Not only do they contain 29.4 grams of high-quality whey protein, but also 20 minerals and vitamins, fibre to keep you fuller for longer, and pre and probiotics for optimal gut health — all in just 205 calories.

That said, plant-based protein is still a positive alternative, particularly for those with dietary or lifestyle needs that make animal-based protein not a viable option.

How much protein is too much?

While we know that too much protein contains serious health risks when it comes to vital organs such as the liver, heart and kidneys, exactly what constitutes ‘too much’ or 'excess protein' is often debated by scientists and medical professionals.

That said, many agree that no more than 2 grams of protein per kilo of your body weight a day is a reasonable recommendation for your total protein intake [6].

How to optimise protein absorption

While in an ideal world, our bodies would always be able to optimise protein absorption itself, there are times when we might need a little helping hand to get that protein synthesis started and those good amino acids to where they need to be.

This can happen particularly for those with health issues or under strenuous workout schedules, but our ability to break down proteins also naturally decreases as we age, so helping ourselves to help ourselves can be a great way to improve our overall health.

Some ways that can help you to optimise protein absorption include:

Eating acidic foods

Acidic foods like orange juice, vinegar and most types of fruit contain proteases that can help to build up healthy acids in your stomach, which can break the bonds holding amino acids together, helping your body to get the most out of every meal.

Taking vitamin B6

Vitamin B6 helps the enzymes in your body to break down protein and carry the amino acids to the bloodstream.

Vitamin B6 is found in a lot of protein-heavy foods such as meat, fish, seeds, beans, nuts, legumes and whole grains, so odds are you’re getting your share already, but you can boost your supply with a B multi-complex vitamin too.

Eating complex carbs with your protein-rich food

A lot of celebrities tout the brown rice and chicken diet when they’re training for those superhero roles, and it turns out they’re onto something.

Carbohydrates help your body to release insulin, and elevated insulin levels help your muscles to absorb amino acids. Complex carbohydrates and protein together have been found to be especially useful for high-intensity workouts and muscle-building exercises.

Consuming protein before and after workouts

Eating proteins before and after exercise gives your body the fuel it needs to not just maximise your workout, but for muscular recovery afterwards. It puts that protein to work [7]!

If you have any questions or concerns, be sure to speak to a healthcare professional.

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