Supplements

5 Reasons Why Plant-Based Protein May Not Be The Best Option & What to Use Instead

Written by Kat Kennedy, NASM CPT, NCSF CPT, NCSF SNS
Medically Reviewed by Dr. Elaine Gavalas, ND, PhD

September 12, 2024

We're living in a golden age of protein powders. I remember when I had to go to a specialty supplement shop just to find a minimal selection of questionable quality. But now grocery store shelves are lined with beef, whey, hemp, soybean, pea, and more.

But with so many different protein powders, how do you know which type is the best? I mean, they all look alike and taste at least vaguely similar (though some are drastically better than others), so it can be easy to think that their benefits are also the same. But don't be fooled. Animal protein powders (like beef and whey) and plant powders (like soy and pea) don't always have the same impact on your body. 

Here’s what you need to know.

Table Of Contents

What is Protein Powder?

But first things first, what exactly is protein powder?

Protein powder is a dietary supplement that provides a concentrated source of protein, typically used to help meet daily protein needs, especially if you’re active, building muscle, or trying to recover from exercise. It’s also convenient if you struggle to eat enough protein from whole foods alone and comes in various forms.

Different Types of Protein Powder

Now that we know what protein powder is, it's time to break down the different types, how they’re made, and what attributes make them so popular (1, 2).

Animal-Based Protein Powders

Whey Protein

  • Source: Whey protein comes from milk and is produced as a byproduct during the cheese-making process. When milk is curdled to make cheese, it separates into solid curds (used for cheese) and liquid whey. The liquid whey is then processed and dried to create whey protein powder.
  • Why It's Popular: Whey is a complete protein, meaning it contains all nine essential amino acids. It's quickly digested and absorbed, making it ideal for post-workout recovery. Whey also has a high leucine content, a key amino acid for muscle growth.

Casein Protein

  • Source: Like whey, casein is also derived from milk. It makes up about 80% of the protein found in milk. Casein is the curd part of milk that solidifies during cheese production. This protein is processed and dried to make casein protein powder.
  • Why It's Popular: Because it releases amino acids slowly, casein is often taken before bed to support muscle recovery during sleep. It’s great for long-term muscle repair but less suited for immediate post-workout needs. 

Beef Protein

  • Source: Beef protein powder is made by extracting protein from beef, usually by boiling the beef and then isolating the protein from the fats and carbohydrates.
  • Why It's Popular: Beef protein is rich in collagen and amino acids important for joint and muscle health. It’s a good alternative for those who want to avoid dairy but still prefer animal-based proteins.

Popular Plant-Based Protein Powders

Soy Protein

  • Source: Soy protein is made from soybeans. The soybeans are dehulled, defatted, and processed into a protein isolate.
  • Why It's Popular: Soy protein is one of the few plant-based proteins that contain all essential amino acids. 

Hemp Protein

  • Source: Hemp protein is made from hemp seeds, which are harvested from the hemp plant. The seeds are ground into a fine powder after their oil content has been extracted. 
  • Why It's Popular: Hemp protein is packed with fiber, omega-3 fatty acids, and some essential amino acids.

Pea Protein

  • Source: Pea protein is typically derived from yellow split peas. The peas are dried, ground, and processed to remove most of the starch and fiber, leaving behind a protein-rich powder.
  • Why It's Popular: Pea protein is hypoallergenic and rich in muscle-building amino acids like arginine.

5 Problems with Plant-Based Protein Powders

While plant-based protein powder has its benefits, it might not be the ideal choice for everyone. Here are five reasons why plant-based protein may fall short of your needs.

1. Incomplete Amino Acid Profile

Amino acids are the building blocks our bodies use to make proteins, which are super important for muscle growth, wound healing, keeping our immune system strong, creating energy, and helping our brains function properly (3). 

One of the main issues with plant-based protein sources is that they often don’t have a complete amino acid profile (the exception being soy). When your diet is missing an essential amino acid, your body might break down muscle to get what it needs. 

Unlike animal proteins, which give you all nine essential amino acids, many plant proteins are missing one or more (4). For instance, grains usually lack lysine, while fruits, veggies, and legumes often don’t have enough methionine (5). 

2. Lower in Leucine

Speaking of amino acids, another huge difference between plant and animal proteins is their leucine content. Leucine is a branched-chain amino acid (BCAA) in protein that's most directly involved in muscle growth.

You can think of leucine as a trigger or start button for muscle protein synthesis—the critical cellular process for building muscle. Leucine activates the body's mTOR pathway (6), which controls the anabolic (growth) and catabolic (breakdown) signaling of skeletal muscle.

You need to consume around 2.5 to 3 grams of leucine at a time to trigger this muscle growth (7). Animal proteins are naturally higher in leucine, so it's reasonable to reach this 2.5-gram threshold in just one serving. 

That's not the case with plant proteins. Soy and hemp protein powder typically have 7.8% and 5.1% leucine content, respectively (8). This means it would take up to 50 grams of hemp (which could take up to four scoops or more) ​​to trigger muscle growth.

3. Can Be Harder to Digest

Protein digestibility is measured by a PDCAAS, or protein digestibility-corrected amino acid score (9). This score measures how much of a protein's amino acids our bodies absorb, with the highest possible score being 1.0 (100%). 

Plant-based proteins often have fibers and compounds like antinutrients (phytates and lectins) that make them harder for our bodies to digest and absorb. Plant-based protein powders, especially those with pea protein, may cause bloating and cramping—especially if you have irritable bowel syndrome.

In contrast, animal-based proteins are more easily digested and utilized by the body.

4. Limited Essential Nutrients

While plant-based protein powders offer a range of nutrients, they often fall short in delivering essential vitamins and minerals compared to their animal-based counterparts. 

For instance, many plant proteins lack vital nutrients like vitamin B12, which is crucial for energy production and neurological function, and iron, which plays a key role in transporting oxygen throughout the body (10, 11). Without these essential nutrients, you might find yourself missing out on what your body really needs to function at its best.

5. May Contain Heavy Metals

Finally, plant proteins are more likely to contain heavy metals like lead than animal proteins—which makes eating them in large quantities less appealing.

A report from the Clean Label Project tested 53 brands of protein powder and found that, on average, plant proteins contained twice the amount of lead per serving as animal proteins (12). They found measurable levels of lead in 75% of plant protein powders tested (including organic varieties).

A Better Alternative: Hydrolyzed Beef Protein

Hydrolyzed beef protein is a fantastic option for a protein powder, especially if you're looking for something that's easy to digest and packed with amino acids. What makes it unique is that it goes through a process called "hydrolysis," where the protein is broken down into smaller peptides (13). This makes it easier for your body to absorb and use, meaning faster recovery and muscle repair after a workout.

Another big plus? Hydrolyzed beef protein is dairy-free, so it’s perfect for anyone who’s lactose intolerant or looking to avoid milk-based products like whey or casein. Plus, it’s rich in collagen, which can help support your bone, joint, and skin health, making it a win for both fitness and overall wellness (14).

Native Note: Just make sure to look for a high-quality supplement that is third-party tested and doesn’t contain added sugars, artificial sweeteners, or flavorings.

The Bottom Line

Plant-based protein powders may seem like a good choice for some, they do come with a few downsides. They’re not a complete protein source, have less leucine (which is key for muscle growth), can be harder to digest, and don’t offer the same essential nutrients you’d get from animal-based options. Plus, there’s the possibility of heavy metals lurking in some brands. 

Hydrolyzed beef protein is a great animal-based alternative since it has a complete amino acid profile—including leucine— and easy to digest since its dairy-free. It is also a source of collagen to support your bone, joint, and skin health.

Kat Kennedy
Article by

Kat Kennedy

Kat Kennedy is the Fitness and Nutrition Editor at NativePath. With a NASM CPT, NCSF CPT, and NCSF Sports Nutrition Certification, she has a passion for giving people the tools they need to feel healthy, strong, and confident.

Read More
Share onfacebook

    Medical Disclaimer

    This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Dr. Chad Walding nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement, or lifestyle program.

    Leave a Comment