Animal vs. Plant Protein: What's the Difference?

Last updated on March 25, 2021 at 02:07 pm

Animal vs. Plant Protein is always a great conversation starter. Protein is an important part of any diet. It helps build muscle, keeps you full for longer, and maintains key bodily functions.

However, for those trying to eat more plant-based products and meals, it can be hard to know how to replace protein-rich animal products for plant-based alternatives.

Will you be getting the same quality of protein from tofu compared to chicken? How will eating plant-based protein affect your muscle development? What changes can you expect to see in your overall health when transferring from animal to plant-based protein?

These are just some of the questions many people new to a plant-based diet may have.

The science of proteins can help you understand the differences, positives, and negatives of animal protein vs, plant protein.

What is Protein?

A good place to start with the difference between animal and plant protein is understanding the basics of proteins.

Proteins are large molecules found throughout the body. You have protein in your hair, muscle, bones, and organs (1). It is a necessary part of all bodily functions as proteins are required to clot blood, produce hormones, and create certain neurotransmitters.

Proteins themselves are made up of hundreds of smaller molecules called amino acids. Different combinations of the 20 amino acids available create different proteins. The different proportions of amino acids in a protein give the protein it’s characteristics.

Amino acids are the building blocks of life, and the body needs them to build different proteins for different tasks. When you eat food that contains protein, you break it back down into its amino acids. Then they can be redistributed and used to build any of the proteins you require for life and healthy function.

So whether you’re eating protein from peas or poultry, it’s all made of the same basic amino acid building blocks, just in different amounts.

What Happens if You Don’t Get Enough Protein?

If your levels of dietary protein intake aren’t sufficient, you won’t be getting enough amino acids for tissue protein development.

This will cause a reduced rate of tissue protein synthesis and can then result in reduced muscle mass (2). This is because your body tries to make up for the amino acid deficiency by taking protein from your muscles to use for key bodily functions.

Severe protein deficiencies, often only seen in those who are seriously malnourished, can also result in a reduction in tissue proteins that can have serious and significant consequences. One of these consequences is edema, which results in swollen, puffy skin (3).

The protein albumin plays a key role in maintaining blood circulation, but in severe protein deficiencies, there are not sufficient amino acids available to create healthy levels of albumin, leading to issues in blood circulation and the symptoms of edema.

Incomplete vs. Complete Proteins

The 20 amino acids that the body uses to build proteins can be classified into two categories: essential or non-essential.

Non-essential amino acids can be produced by the body, whereas essential amino acids can’t and need to be procured through diet in order to meet the body’s varied health, growth, development, and maintenance needs (4).

There are nine essential amino acids that you have to get from your food. Essential and non-essential amino acids help classify proteins into complete and incomplete proteins. A protein that contains all nine essential amino acids is considered a complete protein, and a protein that lacks one or more essential amino acids is classified as an incomplete protein.

The differences between plant and animal proteins come mainly from the distinction between complete and incomplete proteins. While they might be made up of similar building blocks, plant and animal proteins don’t follow the exact same blueprint.

Most complete proteins come from animal sources (5). Foods such as fish, eggs, chicken, and beef all contain the nine essential amino acids, making them complete proteins. Most plant-based protein sources are made of incomplete proteins. Foods such as vegetables, grains, and nuts lack one or more essential amino acids.

But not all plant-based proteins are incomplete! Whole forms of soy such as edamame beans or tofu are complete protein sources.

Is Plant-Protein Worse Because It’s an Incomplete Protein?

Although the term incomplete protein may not sound positive, it isn’t a big deal when you look at the total consumption of essential amino acids (6).

A balanced plant-based diet that includes a range of incomplete plant-based proteins should provide you with all the essential amino acids that you need to maintain proper bodily functions and health.

Don’t get too caught up in the idea that your lentil curry is made of incomplete proteins because the amino acid building blocks are the important nutritional benefit of proteins.

As long as you’re getting all of the essential amino acids, it doesn’t matter if they come from complete or incomplete protein sources.

Animal Protein vs. Plant Protein, What’s Better?

When it comes to choosing a protein source, other nutrients present in the food are also worth considering, and this is where you start to see a difference between animal and plant protein.

Animal protein tends to be higher in saturated fat and cholesterol than plant protein, which can have serious health implications.

Saturated fats refer to the fats that have only single bonds between their fatty acid chains. Saturated fats have been linked to a range of negative health effects, with studies showing that they can increase your risk of inflammation, heart disease, obesity, and a range of other health conditions (7, 8).

Animal protein sources like pork and dairy are particularly high in saturated fats. A pork belly is made up of almost 25% saturated fat and heavy cream contains 23% saturated fat (9, 10).

The difference between animal and plant protein is starker when you compare their saturated fat content. Plant-based protein sources such as tofu and chickpeas deliver on protein while only containing less than one gram of saturated fat each (11, 12).

While this doesn’t mean that all animal protein is bad for you, the lower saturated fat content in plant-based protein choices indicates that plant-based protein may be advantageous for people at a higher risk of diseases like heart disease or other obesity-related illnesses.

Plant-Based Protein May Lower Your Risk of Heart Disease

Plant-based proteins make a great choice for those looking to reduce their risk of diseases related to increased saturated fat intake.

One study found that eating a high plant-protein diet that was also low in carbohydrates managed to significantly lower cholesterol levels (13). This high plant-protein diet was also more effective than a high-carbohydrate, low-fat diet at improving heart disease factors.

Another study involving rat models found that rats who were fed plant-based protein had lower HDL cholesterol levels than rats who were fed animal protein (14). HDL is considered the “bad” cholesterol and having lower levels of it is beneficial to your overall health.

The study indicates that plant protein may offer an advantage over animal protein in its ability to reduce cholesterol levels and other heart disease risk factors.

Additional Benefits of Plant-Based Protein

Aside from protein type and saturated fat content, different proteins can also provide you with a range of nutrients.

Animal protein, for example, is one of the richest sources of vitamin D, with eggs, salmon, and cheese being quite high in the vitamin.

On the other hand, it can be a challenge to find a plant-based protein high in natural vitamin D, with only certain types of mushrooms containing adequate levels.

But plant proteins have some nutritional advantages over animal proteins as well. For example, plant-based proteins are typically high in fiber, while you won’t find any fiber in animal proteins. Fiber is important for maintaining bowel health and low cholesterol.

When it comes to deciding if animal protein or plant protein is the healthier choice for you, there is a range of nutritional benefits that you could cherry-pick to make a case for either one.

The real take-home from their nutritional differences is that there are different benefits to be gained from both animal and plant protein.

Animal vs. Plant Protein for Building Muscle

Another common question regarding protein is which protein is best for muscle development, animal or plant?

While plant protein can provide you with an adequate level of protein and amino acids for muscle development, there are some characteristics of plant protein that make them slightly less successful than animal protein when it comes to bulking-up.

Plant-based proteins tend to have a lower digestibility and lower levels of amino acids such as leucine and lysine. This means that amino acids from plant protein tend to not be used for the creation of muscle proteins and are instead directed towards oxidation.

While plant-based proteins are valuable in maintaining human health, studies have shown that animal protein may have a greater ability to enhance muscle growth and maintain muscle mass (15).

But it’s not all bad news for vegans who want to bulk up. A 2019 study found that after supplementing with either whey (animal) or pea (plant) protein alongside high-intensity functional training workouts for eight weeks, participants saw no body-composition differences between the two proteins (16).

This tells us that plant-based protein may still offer a lot of potential for muscle growth, especially when combined with high-intensity workouts, meaning it’s fine for both the average joe and athletes.

What Are the Best Plant-Based and Animal Protein Sources?

Whether you are thinking about giving up animal protein or just thinking about adding more plant-protein to your existing diet, you’re going to want to consume foods with the highest protein amounts.

High protein animal foods

Chicken
Dairy products
Eggs
Fatty fish such as salmon and mackerel
Beef sirloin and other lean cuts of beef
Pork tenderloins

High protein plant foods

Tofu
Broccoli
Lentils
Chickpeas
Peanuts
Broccoli

Both animal and plant-based foods offer a range of healthy protein sources. It comes down to your preferences and priorities when deciding whether animal or plant protein is best for you. Plus, you can always have the best of both worlds and try them all.

The Bottom Line

Animal vs. Plant Protein? Protein isn’t just there to keep you full and help you out at the gym. It’s one of the building blocks of your body, containing the amino acids you need to undergo almost all bodily processes.

Protein is so important you wouldn’t exist without it. So with protein being such a fundamental key to your health, it would stand to reason that the type of protein you choose to consume is an important choice.

When it comes to animal and plant protein, at first glance they are quite similar. Both are chains of amino acids. However, when you look closer, the two proteins have many differences, from amino acid makeup to nutrient content.

The main negative of animal protein is the high saturated fat content and for plant protein, the disadvantage is the possible reduced-muscle growth potential. But more science is needed to fully understand the effects of each.

These differences don’t necessarily mean that one protein is better or worse than the other. While plant protein may have more fiber content, animal protein is higher in certain vitamins.

It comes down to your personal preference and what your health and diet goals are. The good news is, whether you’re a staunch meat-eater or a proud vegan, there’s a strong protein option for you.