Animal vs. Plant Protein — What’s the Difference?
Eating enough protein daily is important for your overall health.
Protein is necessary for critical processes such as immune function, cellular processes, cell structure, and growth, among others. Thus, it’s essential to consume enough protein on a daily basis (1).
You can get protein from many food sources, including plants and animals.
Some people claim that the source of the protein, whether animal or plant, doesn’t matter. Others suggest that one type of protein is superior to the other.
This article compares animal and plant proteins.
The amino acid content can differ
Proteins are made up of amino acids. The human body uses about 20 different amino acids to build proteins.
Your body can make some amino acids itself, but you have to get nine of them — known as essential amino acids — through your diet.
Protein sources can vary greatly in the types of amino acids they contain.
Generally, animal proteins are known as complete proteins, meaning they contain all nine essential amino acids.
While some plant proteins, including pea protein and soybeans, are also complete protein sources, many other plant foods are considered incomplete proteins (
This means plant foods such as beans, peanuts, and wheat are rich in total protein but lack one or more of the essential amino acids. Still, you can easily combine these incomplete plant protein sources to meet your body’s needs.
For instance, a peanut butter sandwich is a tasty example of a combination that results in a complete protein source. While wheat used to make bread is low in the amino acid lysine, peanuts are rich in it, resulting in a complete protein meal or snack (
It’s important that people eating a vegetarian or vegan diet enjoy a variety of plant protein sources to ensure they’re getting all the essential amino acids.
SUMMARYAll proteins are made up of amino acids, but different protein sources contain varying amounts and types of amino acids.
Rich protein sources
A wide variety of both animal and plant protein sources are available for you to enjoy.
Animal protein sources
Rich sources of animal proteins include:
- eggs
- fish and seafood
- lean meat
- poultry
- wild game
- dairy products such as milk, yogurt, and cheese
Generally, animal protein sources also supply other important nutrients, including vitamin B12 and a type of iron called heme iron. Heme iron is more readily absorbed than the iron found in plant foods, which is known as non-heme iron.
Keep in mind that some animal proteins are less nutritious than others. For example, ultra-processed animal products such as hot dogs and chicken nuggets are high in unhealthy fats and sodium and aren’t ideal for overall health.
Instead, choose nutritious sources of animal-based protein like whole eggs, salmon, chicken, turkey, and shellfish.
Plant protein sources
There are many sources of plant proteins, such as:
- beans
- nuts
- legumes
- soybean products like tofu, tempeh, and edamame
- buckwheat
- Ezekiel bread
- quinoa
- wheat
- wild rice
- nutritional yeast
- chia seeds
- hemp seeds
- spirulina
Ezekiel bread, quinoa, buckwheat, spirulina, soybeans, nutritional yeast, chia seeds, and hemp seeds contain all nine essential amino acids, meaning they are complete protein sources.
Other plant protein sources, such as beans, nuts, legumes, wheat, and wild rice, are too low in or missing one or more essential amino acids.
However, because plant foods contain varying amounts of different amino acids, getting all the essential amino acids on an exclusively plant-based diet is still manageable — it may just take a little more effort.
Consuming a varied diet and combining complementary plant proteins, as in the peanut butter sandwich mentioned earlier, will ensure that you get all the essential amino acids in your diet.
Some other examples of complete protein combinations are hummus and pita bread, rice and beans, and pasta salad with kidney beans.
SUMMARYAnimal and plant protein sources are plentiful. Complete protein options are available in both animal and plant form.
Plant-based diets have been associated with significant reductions in blood pressure compared with diets rich in animal protein.
Furthermore, studies suggest that people eating a vegetarian diet also tend to have lower body weight, lower cholesterol levels, and lower risk of stroke, cancer, and death from heart disease than people who eat meat.
However, not all plant-based diets are created equal, and not all plant foods are necessarily beneficial for heart health.
One study associated plant-based diets rich in nutritious plant foods like whole grains, vegetables, nuts, and seeds with a lower heart disease risk.
Meanwhile, plant-based diets rich in less nutritious options such as fried vegetables and refined grains were associated with a higher risk.
Plant-based diets may also benefit blood sugar management. Several observational studies have shown that these diets can be beneficial for both treatment and prevention of type 2 diabetes.
Diets rich in nutrient-dense plant foods such as whole grains, fruits, vegetables, nuts, legumes, and vegetable oils are particularly associated with a significantly decreased risk of developing type 2 diabetes.
While these results are promising, they do not prove that these health benefits come from eliminating animal protein sources — the benefits may just as likely be a result of increased consumption of nutritious plant foods.
SUMMARYA diet high in plant protein has been linked to a lower risk of heart disease, diabetes, and obesity.
Animal protein also has health benefits
Certain animal protein sources are also associated with positive health effects .
For example, eating fish regularly has been linked to many health benefits, including lower rates of cognitive decline and heart disease.
Eating animal protein has also been linked to increased lean muscle mass and a reduction in the muscle loss that occurs with age.
SUMMARYCertain animal protein sources are linked to a reduced risk of heart disease, improved cholesterol levels, and increased muscle mass.
While red meat is a complete protein source, several observational studies have linked red meat consumption to an increased risk of heart disease and stroke.
However, research is mixed.
Some researchers suggest that these adverse health effects may not be associated with all types of red meat, but rather with processed red meat.
For example, a recent review found that red meat doesn’t increase the risk of heart disease if consumed within recommended portions.
Nonetheless, another study found that eating large amounts of unprocessed red meat was associated with a 9% increase in relative risk of heart disease, while eating large amounts of processed meat was associated with an 18% increase.
It’s important to note that these health risks don’t appear to be linked to eating fish or lean meats such as turkey and chicken.
SUMMARYWhile research is mixed, both unprocessed and processed red meat have been associated with an increased risk of disease. Other animal proteins, such as fish and poultry, have not been linked to these negative health outcomes.
The bottom line
Many considerations may come into play when choosing between animal and plant protein sources.
Both animal and plant proteins offer beneficial qualities. Each type also has some drawbacks.
Rather than focusing on consuming one or the other, it may be better to focus on eating a varied diet rich in both nutrient-dense plant proteins and lean animal proteins.