Which protein is best for me?

Proteins are important, especially when you engage in strength training. This is something that’s now widely known. Proteins contribute to the growth of muscle mass and the recovery of muscles after (strength) training. Even when muscle growth isn’t your primary goal, it’s still beneficial to consume enough protein. These same proteins help maintain muscle mass and are essential for the preservation of strong bones. As a result, many people increase their protein intake as soon as they begin strength training. But did you know that just looking at the protein content doesn’t tell the whole story? The quality of the protein you consume is equally important! In this article, we’ll explain what protein quality really means and what you should pay attention to regarding your protein intake.

Back to Basics: Amino Acids

The following section dives deep into amino acids. If this theory doesn’t interest you, feel free to skip ahead. As you may know, proteins found in food are made up of amino acids. Amino acids are organic compounds with various effects, and when combined, they form proteins. In nature, there are around 500 different amino acids known, but luckily, we don’t need all of them. Only 20 amino acids from those 500 are found in human protein, referred to as fundamental proteins. These 20 fundamental proteins can also be split further. The body is capable of synthesizing some of these amino acids—12 to be exact. This process is called synthesizing. However, the other 8 amino acids can’t be produced by the body and must be sourced from elsewhere. These 8 are known as essential amino acids, meaning they are necessary for the body and must come from food.

The 8 Essential Amino Acids Are:

• Leucine*
• Isoleucine*
• Valine*
• Lysine
• Tryptofaan
• Fenylalanine
• Threonine
• Methionine
• Histidine**
• Arginine**

You might notice that 3 of these amino acids are marked with an asterisk. This creates another category, known as branched-chain amino acids. You may not be familiar with the term, but these are the well-known BCAAs, or Branched-Chain Amino Acids. These three amino acids have unique properties, including a branching structure that other amino acids don’t possess. You might wonder, “Is that all?” And you’re right to ask! But no, that’s not all. What makes these amino acids even more remarkable is that they make up about 35% of the essential amino acids in muscle tissue. These three BCAAs play a significant role, especially when it comes to strength training. Leucine, in particular, has even more special properties. It can directly activate the mTor signaling mechanism, which triggers many important processes, the most significant being the activation of protein synthesis, essential for muscle growth! You may have also noticed the inclusion of two additional amino acids, bringing the total to 10 essential amino acids. Histidine and Arginine are technically essential, but research has shown that their absence doesn’t negatively impact the body’s nitrogen balance. For this reason, they aren’t strictly considered essential amino acids and are sometimes referred to as semi-essential amino acids. It’s wise to consume enough of them, but they won’t dramatically affect your overall results.

What Should I Do With All This Information?!

That’s a lot of theory, but what does it all mean for you? The key takeaway is that not all protein is the same. Proteins are made up of different amino acids, and as we explained above, certain (essential) amino acids play a more significant role than others. So, it’s not just about getting enough protein, but also about ensuring that the proteins you consume are of high quality. In theory, you could eat plenty of protein but still not experience the full benefits due to the amino acid profile. A great example of this is gelatin. You may have noticed that gelatin is composed of 90% protein—almost as much as a high-quality isolate protein. However, gelatin offers little nutritional value because it consists almost entirely of non-essential amino acids. In fact, the branched-chain amino acids leucine, isoleucine, and valine are entirely absent from gelatin.

So, protein content isn’t everything. But how should we approach this? It’s not realistic to expect everyone who goes to the gym to become a scientist who understands all the ins and outs of amino acids. You’d need to calculate the amino acid profile of every food you eat and assess how it contributes to your goals. Fortunately for us, two researchers did the hard work back in 2004! [1]

The Quality of Protein

In 2004, two researchers realised that not all proteins are created equal, but making a good comparison for the average person would be an almost impossible task. For that reason, they decided to come up with several criteria to measure protein quality. They decided to evaluate proteins based on amino acid profile, digestibility, and the biological availability of amino acids. From this, different methods of measurement were developed, including the following:

The Protein Efficiency Ratio (PER)

The PER is a fairly primitive method. It measures the effectiveness of a protein based on the growth of an animal. In this case, rats were fed different protein sources, and their weight gain was measured to determine the protein’s effectiveness. However, this method was only conducted on rats, so it’s not comparable to the human body.

The Biological Value

The second method is the Biological Value, or better known in the Netherlands as the biological availability of a protein. This method measures nitrogen levels to determine how efficiently the body can use the protein from food. Foods with high-quality protein result in a higher reserve of essential amino acids in the body.

The Net Protein Utilization

The Net Protein Utilization is closely related to biological availability, with one major difference. This method also considers the effect of protein over a longer period, whereas the biological value focuses primarily on the time immediately after ingestion.

The Protein Digestibility Corrected Amino Acid Score (PDCAA)

This last method evaluates protein quality in a different way. It looks at the first essential amino acid that is lacking and gives a score based on that. It’s important to note that none of these methods are flawless. They all have limitations, making it essential to consider a combination of results when drawing conclusions.

So, which protein is the best?

The research found that animal protein sources such as eggs, dairy, meat, fish, and poultry scored very well and contained the highest quality proteins. This was mainly due to how complete these proteins were: the essential amino acids were present in sufficient quantities, and the body could process them efficiently. Eggs were designated as the standard with a biological value of 100. Since protein powders are made from dairy, they naturally scored very well too. In fact, whey protein even outscored eggs in terms of biological availability! This is because whey is a highly concentrated product with large amounts of essential amino acids, particularly the BCAAs. That explains why whey is so popular in the fitness and strength training world. Interestingly, casein protein did not score as well compared to whey, but this was a perfect example that these numbers don’t tell the whole story. Casein has the property of forming a sort of ‘gel’ in the stomach, leading to a slow release of amino acids. This makes casein very efficient at delivering amino acids over time, making it a valuable protein source for specific times, such as overnight. Whey provides the fastest and highest increase in protein synthesis, while casein gives a more moderate and sustained rise.

Plant-Based Proteins

In addition to animal proteins and protein supplements, we also have plant-based protein sources. When looking at black beans, peanuts, and wheat gluten, something becomes immediately clear. The numbers are significantly worse than those of animal proteins. Ranging from virtually no effect to a moderate effect on protein synthesis, these plant-based protein sources appear much less effective. The researchers did note that combining these plant-based protein sources could largely offset this effect. By combining different protein sources, various amino acid profiles are combined to create a fairly complete protein. Soy protein stood out the most among plant-based protein sources. Although its biological value is lower than that of animal protein, it still scored relatively well with a decent PER and PDCAA score. If soy is one of your primary protein sources, perhaps because you’re vegetarian or vegan, it might be a good idea to consume a bit more protein on average to compensate for the lower amounts of essential amino acids.

Be cautious with soy

However, it’s important to be aware of two key factors when it comes to soy: isoflavones and anti-nutrients. Soy is rich in isoflavones, which produce phytoestrogens in the body. This can lead to increased estrogen levels (the female sex hormone), which can be problematic, especially for men. Additionally, many soy products are rich in anti-nutrients, which have the unfortunate property of impairing the effectiveness of amino acids. Without delving too deeply into these topics, it’s best to choose traditionally fermented soy products over commercially processed products that contain soy.

Protein quality rankings

Below are the results of the research...

Information sourced from the U.S Dairy Export Council, Reference Manual for U.S. Whey Products 2nd Edition, and Sarwar, 1997.

Conclusion on Protein Content

As you've read, choosing the right protein source is crucial for achieving your fitness goals. Animal proteins, such as those found in eggs, dairy, meat, fish, and poultry, have a high-quality amino acid profile that is efficiently absorbed by the body. Whey protein, derived from dairy, is a top choice for quick protein synthesis, while casein is ideal for a slow release of amino acids throughout the night.

Hopefully, this article has clarified that not all proteins are the same. Protein quality is determined by various factors, with the amino acid profile being a major one. If animal proteins and protein supplements are your primary source of protein, there's little to worry about, and you can easily follow the recommended protein intake for strength training. However, if you avoid animal protein for any reason and rely on plant-based protein sources, it’s important to be more mindful. Increasing your total protein intake by around 20% seems like a smart move, and combining different protein sources is advised to ensure a more complete amino acid profile (including essential amino acids) with each meal.

It’s important to remember that while proteins are essential, you should not exceed your calorie and protein intake based on your fitness goals. Excessive intake can be counterproductive and hinder your progress. Therefore, we recommend using our macros and calorie calculator to precisely calculate your needs to optimize your performance and reach your goals.

Plant-based proteins can also be a valuable addition to your diet, especially when combined to create a complete amino acid profile. However, be cautious with soy products due to the potential presence of phytoestrogens and anti-nutrients; it's preferable to opt for traditionally fermented soy products.

We hope our blog helps you make informed decisions about choosing the right protein source for your fitness or health goals.

References

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3905294/