Animal Protein Vs. Plant Protein

The protein powder aisle at most grocery and health food stores can seem like its own mega mall. Shelves upon shelves offer packets and jars of every shape and size, in every flavor and of every type. While the actual protein in protein powder can come from a variety of sources, many fall under the category of “whey” or “plant.”

Here, we explore their key similarities and differences and how each helps to meet this essential dietary need that helps keep the body working, powering everything from brain function to cell building.

whey protein


Unlike plant proteins, whey is considered an animal protein because it’s made from cow’s milk. When curdled, milk creates curds (used for cheese) and whey, a watery substance that separates out from the solid material.

While it does come from milk, whey is still naturally low in lactose, making it a good substitute for anyone with a lactose sensitivity or for infants that need a milk-based formula to help nourish their bodies. It’s sold in both powder and liquid forms.

There are three types of whey protein, each with its own nutritional value.

  • Whey protein isolate: This type of whey is processed to remove all lactose and fat, leaving an end-product that is 90 percent pure protein.
  • Whey protein concentrate: The nutritional makeup of whey protein concentrate exists on a sliding scale. The concentration can be adjusted to have different levels of fat, carbohydrates, and protein.
  • Whey protein hydrolysate: This type of whey has already undergone hydrolysis, or the absorption that comes from a reaction with water. This makes it extremely easy for the body to digest. Whey protein hydrolysate is most often used in medical supplements and baby formula because of this unique facet.

Whey protein nutrition

Whey is considered good for the body because of its strong protein content, including amino acids. In fact, whey is one of the best sources of branch-chained amino acids, a group that includes leucine, which stimulates muscle growth and activation.

Beyond just the high protein content and amino acid levels, which are an important component of cell re-growth, muscle building, and tissue repair, whey’s gluten-free nature and low lactose means choosing it can offer some pretty impressive benefits. That includes helping to prevent and reduce allergic skin reactions and milk allergies.

Be wary of adding too much whey into your daily diet, though. The side effects of consuming too much too quickly overshadow the benefits and can lead to:

  • Bloating
  • Nausea
  • Excessive thirst
  • Fatigue
  • Cramps
  • Increased bowel movements
  • Loss of appetite
  • Headaches

That’s because ingesting more whey introduces the body to more casein, a type of protein found in milk that’s usually separated out when whey is made, but trace amounts could still remain and in some people could trigger a reaction, often resulting in inflammation of the intestines that leads to some of these symptoms.

The argument for whey and animal protein

The reason for why whey has remained so popular is because, as an animal product, it’s considered a “complete” protein, meaning a protein that contains all the amino acids the body needs to function. Complete proteins are largely found in animal products like milk, cheese, yogurt, meat, fish, poultry, and eggs.

In the past it was also argued that, because humans are technically mammals, animal proteins like whey are easier to digest, and are used more readily by the human body.

However, these claims have since been disproven. In fact, science shows that all protein comes from plants. Even animal protein leads back to plants, since animals had to eat vegetation to get their own supply. As such, eating plant protein provides the same benefits as animal protein, with some added perks.

plant protein


Just as the name implies, plant protein comes from plants. While not every plant has a surplus of every single essential amino acid the body needs, there are still several options that in fact do. That list includes:

  • Quinoa
  • Peas
  • Soy (used to make tofu and tempeh)
  • Chia
  • Hempseed
  • Chickpeas

These options are all considered “complete” protein sources, since they give the body all the amino acids it needs to do its job, without the need for animal byproducts—and that’s good news for vegetarians, vegans, and anyone else that needs to eliminate dairy from their diets.

Plant protein nutrition

At the core, plant protein is pretty similar to animal protein, with a couple of exceptions. Vegetarians and vegans normally have lower amounts of two essential amino acids, methionine and lysine, and higher levels of non-essential amino acids like arginine and glycine. (However, the body can make non-essential amino acids from other agents, and doesn’t rely on diet to get them.)

Here are some other proteins found in greater or exclusive concentrations in animal products and byproducts:

  • Methionine is found in dairy, meat, and fish. It helps wounds heal properly and prevents liver damage, particularly in instances of acetaminophen poisoning.
  • Lysine is another type; its specialty is fighting the herpes virus, which can help treat cold sores.
  • Arginine is involved in maintaining hormone function and a healthy immune system, as well as wound healing, artery contraction and dilation, and helping the kidneys to process waste.
  • Glycine helps protect the liver and kidneys from the effects of alcohol and post-transplant drugs.

This doesn’t mean people can’t survive happily and healthily solely on plant protein. Legumes, for example, still have lysine, just in lower amounts.

As long as non-meat eaters are aware of what they’re eating and what their bodies need to stay healthy, animal protein can easily be replaced with plant counterparts. In fact, science tells us the human body can’t differentiate between animal and plant protein in the way it’s digested and used.

And plant proteins offer an overall healthier profile, with better sodium levels and attribution of carbohydrates and fats. In essence, switching to plant protein doesn’t mean living without essential amino acids—it means swapping out a serving of meat for a double serving of vegetables or fruits to make sure the dietary requirements are met in other ways.

Like whey, there are also a number of plant-based protein powders that can easily be added to smoothies and shakes, and other foods.

  • Grain-free protein powder
  • Pea protein: This type shows up quite a bit in plant-protein powders.
  • Hemp protein: Hemp is another solid source of plant protein with branched-chain amino acids.

The argument for plant protein

Even if you don’t make the full switch, there are plenty of reasons to adopt more plant protein into your everyday diet. The added vitamins, minerals, and antioxidants means that people that consume more plant protein tend to enjoy these benefits:

  • Lower rates of diabetes
  • Fewer instances of heart disease
  • Reduced risk of cancer
  • A lower body weight

Also, plants don’t have any cholesterol, so plant-based diets reduce the body’s levels, too.

Even better, eating more plants also has a range of positive environmental effects. Producing just one gram of meat requires up to 26 times more fossil fuels, land, and water than producing one gram of soy protein.

Eating more plants and fewer animals can also help reduce greenhouse gas emissions (from fewer farms and livestock) and cut down on the destruction of natural animal habitats as space is cleared for livestock farmland.


There’s no one way to choose a side when it comes to protein. There are passionate advocates on both sides of the coin. Both plant protein and whey/animal protein will help fuel the body and keep it working like it should, so it really comes down to a question of preference.

The references cited in this blog post point to a developing trend for plant protein since several studies on it have been completed in recent years. That would say there’s a growing interest in switching to plant protein, perhaps as more and more people switch to vegetarian and vegan diets, whether for health, environmental, or ethical concerns.

If reducing animal protein sounds like a good idea, you can make things a bit easier by working with vegetables that are in season and supplementing with a variety of plant-based protein powders.

Working with foods that are readily available will cut out a little of the guesswork, making sure these new meals are equipped with the freshest ingredients that won’t take a lot of time or energy to hunt down—and having protein powder on hand makes it easy to get a good dose without any excuses. As always when it comes to wellness, it’s all about finding the right dietary balance to keep the body active, healthy, and thriving.

Reposted with permission from Thrive Market.

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Photo Credit: Thrive Market


John J
John J3 months ago

thanks for sharing

John J
John J3 months ago

thanks for sharing

Julia Oleynik
Julia Oleynik1 years ago

Thank you for sharing

Nang Hai C
Nang Hai C1 years ago


Jim Ven
Jim Ven1 years ago

thanks for sharing.

Robert N
Rob Chloe Sam N1 years ago

Interesting article, Thanks for sharing.

HEIKKI R1 years ago


Trish K
Trish K1 years ago

I had lines in our finger nails. My doc asked if I ate meat. She told me at the very least to eat eggs and yogurt. Lines went away after a year or so and I only eat two or three eggs per week and a 1/2 cup of greek yogurt a day.

Siyus C
Siyus Copetallus1 years ago

Thank you for sharing.

Nang Hai C
Nang Hai C1 years ago