Plant Protein vs. Animal Protein: How Are They Different?

We've all heard the saying, "You are what you eat." And when discussing protein, this couldn't be more true. Protein is an essential food group that helps build and repair tissues in our body. However, not all of them are equal.

Plant-based and animal sources are a hot topic of debate, especially among health-conscious people. Vegetarianism and veganism are becoming more popular. It makes people question if plant-based proteins provide the same benefits as animal protein. 

They’re also wondering if they’re getting enough protein in their diet. Let's look at what foods are high in proteins and how they differ.

What are Proteins?

Before diving into the differences between plant and animal proteins, let's understand more about this food group. They are like the all-stars of your body. Think of them as tiny machines working non-stop to keep you healthy and functioning. 

They play a major role in nearly every biological process, performing tasks like:

  • Building Muscles
  • Aiding Digestion
  • Carrying Oxygen Through the Body
  • Acting as a Messenger (Hormones)

Simpler structures, called amino acids, make up these food groups. They are like tiny building blocks that combine into different patterns. There are 20 essential amino acids that create thousands of these amazing structures for many reasons. 

Here's the catch: our bodies can produce some of these amino acids, but we have to get the 'essential' ones from what we eat. And this is where the debate between plant-based and animal proteins comes into play. Both can offer essential amino acids but in different amounts and combinations. 

What are Animal Protein Sources?

Animal proteins come from animal sources. They include meat, fish, eggs, and dairy products. The foods in this group are our primary sources of vitamin B12, iron, and zinc. A salmon filet contains protein and omega-3 fatty acids, iron, and vitamin B12.

Eggs are protein-rich foods with leucine, an amino acid that stimulates muscle synthesis. Better muscle support is why animal foods are the first choice for athletes and bodybuilders. Some ideal animal sources are: 

While animal sources are nutrient-rich, they have higher saturated fat and cholesterol content.

What are Plant-based Protein Sources?

Many more plant-based proteins come from beans, lentils, peas, nuts, seeds, and whole grains. Soy products like tofu and tempeh also fall into this category. Most plant sources don’t have all the essential amino acids your body needs in one package. Still, you can eat different plant sources and easily get all essential amino acids. 

Beans are rich in lysine but low in methionine, while rice is low in lysine but high in methionine. So, eating rice and beans together provides a complete amino acid profile. Plant proteins have fiber, antioxidants, and phytonutrients that support overall health. Quinoa and soy are exceptions to the rule, being whole food plant sources that provide complete proteins in one package. 

So, if you're contemplating a plant-based diet, variety is the spice of life. Plant-based proteins also tend to be better for our environmental health. Based on this information, one assumes that plant-based sources are better. But it isn't clear which source is best. 

Instead, we should focus on how plant-based and animal proteins differ. What are the main differences, and which source provides the most nutrients?

Main Differences Between Plant Protein vs. Animal Protein

When discussing the main differences between plant and animal proteins, the key is in the amino acids. Animal sources are 'complete proteins' because they have all essential amino acids. But, most plant sources are 'incomplete,' so they lack certain essential amino acids.

Some plant foods, including pea protein and soybeans, are "complete" protein sources. But don't be disheartened. As we mentioned, eating various plant foods throughout the day gives you a complete profile. Another significant difference lies in the additional nutrients.

Animal proteins are rich in nutrients like vitamin B12, iron, and zinc, but not in plants. Plants offer fiber and phytonutrients, which boost health and fight disease with antioxidants.

Antioxidants aren’t present in animal foods. Also, very few plant proteins have saturated fat compared to animal ones. Foods that are higher in saturated fats contribute to more cholesterol. Other main differences between plant proteins vs. animal proteins include:

  • Digestibility: Animal sources are more digestible than plant ones. Our bodies absorb them more easily. The difference in absorption usually ranges from 10% to 20%. It's certainly not a deal-breaker, but it could be meaningful to anyone who needs to eat healthier on a budget.
  • Environmental Impact: Usually, producing animal foods has a higher environmental impact than plants. It requires more resources like water and land, producing more greenhouse gas emissions. The bulk of resource use comes from livestock management and inefficient crop feed.
  • Health Implications: Overeating animal proteins, especially red and processed meats, contributes to heart disease and certain cancers. Researchers associate plant proteins with many health benefits. Some benefits include lower risks of heart disease and type 2 diabetes.
  • Cost: Plant proteins, particularly whole grains, and plant-based meats, are often more expensive than animal proteins. This makes animal foods cost-effective for people on a budget.

If you're trying to decide which source is better, you'll have a hard time. So, choosing between plant vs. animal proteins depends on your dietary needs and overall diet balance.

What are Complete Proteins?

We usually classify proteins as "complete" or "incomplete." Complete sources have all nine essential amino acids our bodies need to function. We can't make these amino acids, so they have to come from food.

While most complete foods are animal-based, there are a few plant-based sources. Complete proteins that most people know are:

  • Meat
  • Dairy
  • Quinoa
  • Soy
  • Eggs
  • Fish

"Complete" and "incomplete" only describe the sources' amino acid profile. You should get essential amino acids if you eat enough calories from a diverse diet of animals and plants. Many researchers consider pea protein powder to be complete, too.

What are Some Good Protein Sources?

If someone asked you how much protein you would need daily, it would be hard to answer. Are you vegan or vegetarian? Do you have diet restrictions and have to eat a dairy-free diet?

Are you trying to build muscle? Animal sources are primarily chicken, beef, fish, eggs, and dairy products. Eating a 3-ounce serving of beef can provide about 22 grams of protein.

Eggs, especially, are an excellent source of animal protein and a versatile choice for meals at any time of the day. Cheese and milk are also high in animal protein and boast the added benefit of calcium, which is vital for bone health. However, these animal sources tend to be high in saturated fats, so moderation is necessary.

The Recommended Dietary Allowance (RDA) is about 0.36 grams of protein per pound. Plant-based proteins, including legumes like beans, lentils, and peas, are dense protein sources. A cup of lentils, which are about 25% protein, can pack up to 18 grams of it.

Soy products like tofu and tempeh are great options, too, with a half-cup offering 21.8 grams of protein. Quinoa is a powerhouse grain, too, and it's also a complete source. Nuts and seeds, like almonds and chia seeds, are also dense proteins and rich in healthy fats and fiber.

Men and women trying to put on muscle should eat 1.2-1.7 grams of protein or up to 0.8 grams per pound of body weight. Since animal foods are easier to absorb, whey protein powder supports rapid absorption. It also has a 2:1:1 ratio of leucine, isoleucine, and valine. 

We need these amino acids to build muscle. Remember, including more plant-based foods can help get the essential amino acids into your body.

Benefits of Animal Proteins

We praise animal foods such as poultry, fish, eggs, and dairy for their high essential amino acid content. Beyond muscle growth, animal proteins also have many vitamins and minerals that are less common. They are high in vitamin B12, D, and heme-iron. 

Our bodies absorb heme-iron better than the non-heme variants in plants. While it's essential to consider your diet, animal sources can meet your nutritional needs. People who eat low-fat sources of animal sources can enjoy other benefits like:

  • Lower Risk of Heart Disease
  • Better Weight Control
  • Lower Risk of Type 2 Diabetes
  • Lower Risk of Stomach, Pancreatic, and Prostate Cancer

Unfortunately, eating animal sources also has some risks. But let's focus on the benefits of plant-based foods.

Benefits of Plant-based Proteins

We also celebrate plant foods like beans, lentils, and nuts for their high nutrient wealth. These sources are low in saturated fat and high in fiber, vitamins, and minerals like potassium and magnesium. They also have many antioxidants and phytonutrients, which help boost our immunity against illnesses.

Diets rich in plant-based proteins offer many benefits like:

  • Lower Risk of Heart Disease
  • Protection Against Many Cancers
  • Lower Risk of Stroke
  • Protection Against Type 2 Diabetes

Another advantage of plant-based proteins lies in their lack of environmental impact. Some plant sources require less water and land and produce less greenhouse gasses, making them a more sustainable choice. In fact, animal products are responsible for 57% of global food-related emissions, whereas plants are only 29%.

While it's true that most plant proteins are 'incomplete,' eating more of them throughout the day can quickly meet your amino acid needs.

The Disadvantages of Animal Proteins

While animal sources have essential nutrients, they carry some drawbacks. One significant concern is their high saturated fats and cholesterol, which can cause heart disease. The American Heart Association says high saturated fats can raise blood cholesterol levels. 

Higher cholesterol clogs the arteries with fat deposits. Research is mixed, though, and some researchers believe the risks of red meat only come from processed sources. Eating large amounts of unprocessed meat increases the risk by 9%, and processed meat increases the risk by 18%.

Another concern is the environmental impact of animal protein production. Raising animals for food demands significant resources, including land, water, and feed, resulting in considerable greenhouse gas emissions. The United Nations Food and Agriculture Organization says livestock production accounts for 14.5% of all human greenhouse emissions.

Specifically, cattle for beef and dairy needs contribute to 65% of emissions. Feed production and manure storage and processing follow closely behind. As we've shown, eating animal-based foods is okay because plant-based sources also have drawbacks.

The Disadvantages of Plant-based Proteins

While plant proteins offer numerous advantages, nutrient availability is one issue with plant-based proteins. Certain essential amino acids, iron, and vitamin B12 are less bioavailable in plant foods than animal foods. Plants have protective coatings that shield them, making it tricky to meet nutrient needs from plant foods alone.

Spinach may have more iron than steak per calorie, but we can't absorb the iron from spinach as easily. With careful meal planning, various plants can provide all the essential amino acids. For instance, you'd need to eat a lot more plants, like legumes, to match the protein content in chicken or eggs.

People should also watch for highly processed plant foods, usually commercially available in stores. We can link processed foods to weight gain and possible increases in cancer risks. It can be challenging, particularly for those trying to meet high-protein diets or with limited access to food.

Which Type is Better for Health?

The answer to this question depends on many factors, including personal preferences and dietary restrictions. Here's a summary:

Carbs and Calories

Plant sources can have more carbs and calories than animal sources. If you're on a low-carb or keto diet, relying on plants for protein and still meeting your dietary goals is challenging. Plant sources can still be a good option if you have more flexibility with your carb and calorie limits.


Animal-based proteins are more accessible to our bodies and easier to absorb than plant-based sources. So, if you opt for plant-based foods, you'll have to eat around 20-50% more to get the same amino acids. You can still meet your goals with plants, especially soy products. 

Remember that plant sources usually force you to eat more food. The additional carbs and calories could hurt your weight loss goals.

Nutrient Profile

Animal-based and plant-based foods each have their unique nutritional benefits. The "protein leverage hypothesis" suggests that protein content and micronutrients drive our cravings. Animal sources, like beef and fish, have B12, D, DHA, heme-iron, zinc, and K2. Plant sources, like legumes and grains, excel in fiber, C, and flavonoids. 

Adding high-fiber foods to your diet is good if you lean toward animal foods. If you’re getting protein from plants, consider supplementing with vitamins and minerals to fill nutrient gaps.

Disease and Longer Life

The impact of plant-based vs. animal-based protein on diseases suggests we should watch animal sources. We associate plants with a lower risk of chronic diseases. Animal sources can increase the likelihood of developing heart disease and stroke.

However, this conclusion is more relevant when people overeat protein from animal sources, especially processed meats. Eating a moderate amount of unprocessed red meat and dairy can be part of a healthy diet. The impact of protein supplementation on human longevity is a topic that sparks much debate.

When considering animal data, lower-protein diets could help us live longer. But here's the thing: we need more evidence from human studies. Now, let's talk about the benefits of consuming more protein. 

It can help with weight loss, improve metabolic health, and even give us more strength. But here's where it gets interesting - it raises a paradoxical question. Do we have to choose between being healthy and living longer? 

The exact impact of animal sources on lifespan is still uncertain. Avoiding meat to increase your lifespan might not make a difference. Plus, the protein we need to prevent muscle loss changes as we age. 

So, restricting protein to live longer may not be the best idea.

The Environment

Cows and other livestock activities release methane, which might have a bigger greenhouse gas impact than chickens or pigs. But, it isn’t easy to calculate how much methane contributes to greenhouse gas emissions. When considering plant-based foods like nuts and nut milk, here's what the data says:

  • Nuts: On average, we use 1,090.4 gallons of fresh water per pound of harvested nuts. Nut milk has gained popularity in recent years, but producing it requires a lot of water. In fact, a study found that a single almond grown in California requires 3.17 gallons of water.
  • Rice: Half the world relies on rice as a staple, but it's one of the thirstiest crops, using around 596 gallons of water per pound. Rice plants are usually underwater while growing. 
  • Pulses: Beans, peas, and lentils require much less water than nuts, with an average of 280 gallons per pound. However, they provide less protein than other options.

Plant-based foods seem more environmentally friendly but require significant water and other resources. Based on health and environmental impacts, a combination of plant- and animal-based sources is more sustainable.

Which Food Source is Better for Building Muscle?

Having a higher protein intake can help with muscle building and maintenance. It won't magically give you the body of a bodybuilder. But, eating more can benefit your muscle mass, especially when you exercise. 

Animal protein powders typically have more advantages than plant-based protein powders for muscle-building. This is an advantage, as leucine - abundant in animal foods - plays a crucial role in muscle synthesis. Due to its richness in leucine, animal sources support muscle protein synthesis more than plants. 

So, instead of focusing on one specific source, aim for diversity in your diet. Include both proteins in your meals using healthy meal prep ideas.

Final Thoughts

Both plant and animal foods have their unique benefits and drawbacks. It's not about choosing one over the other but balancing your lifestyle and nutritional needs. A diverse diet can provide all essential nutrients while supporting overall health.

Above all, listen to your body and make mindful choices. To learn more about nutrition and wellness, check out our other resources on the Reflect blog. And if you have nutrient gaps, consider our range of supplements that support a balanced diet. Remember, a healthier outlook on life starts with hydration, nutrition, and movement.