Animal Protein Vs Plant Protein – Which One Is Better?

With increased awareness of a healthy balanced diet, protein seems to be the common topic on everyone’s mind. This macronutrient, which constitutes about 20% of the human body, has been extensively researched and its benefits professed like holy words. It helps in repairing the muscles after exercise, improves immunity and helps in general building, repairing and maintenance of the body. Protein is made up of amino acids. Humans need an adequate balance of all 20 amino acids to function efficiently. Of these 20, the body cannot produce 9 amino acids labeled as essential amino acids. These essential amino acids must be consumed through our diet and any food source containing all nine is referred to as a complete protein source. In this article, we look at various food sources and compare the benefits of animal and plant-based protein.

Animal-based Proteins-

The major difference between animal and plant-based protein is in their amino acid content. Animal based protein generally tends to be more complete sources of protein albeit with higher fat content. Some complete animal-based protein foods include:

  • Fish
  • Eggs
  • Dairy products
  • Red meat
  • Poultry like chicken

Animal based proteins also contain a variety of additional nutrients which cannot be obtained from plant foods, these include:

However, animal-based protein is not all benefits. It has high levels of saturated fat, no fiber, and carbohydrates. WHO classifies red meat as a Group 2A carcinogen, which might cause cancer and processed meat as a Group 1 carcinogen, which is known to cause cancer. However, lean sources of protein like chicken breast, eggs, ground beef contain less fat and are not harmful to the body.

Plant-based Proteins-

While plant-based protein foods might possibly be incomplete proteins, they are rich in fiber and healthy fats. By consuming multiple plant-based proteins, one can create a complete source of protein. There are some plant-based foods which are complete sources of protein like:

Other sources of protein include grains, rice, oats, hemp, and peas.

Additionally, plant-based foods provide nutrients absent in animal-based proteins like:

Plant based foods also contain high amounts of starch, thus making it impossible to follow a low carb diet, which might possibly be important to a few.

Animal Protein vs Plant Protein- Which one is better?

Now that we have an idea of each type of protein, we can quantitatively and qualitatively compare the benefits and downsides of both.

  1. Health benefits

A plant-based diet is linked to multiple health benefits including low body weight, low cholesterol and reduced risks of cardiovascular diseases. A study on the effect of replacing animal-based proteins with plant-based proteins on glycemic control (maintaining blood sugar in diabetes patients) showed that blood sugar levels were improved meaning diabetes was controlled better. While it may seem that plant-based proteins have many health benefits, animal-based protein also has equally important health benefits. Consuming animal-based protein low in saturated fat and high in unsaturated fat like Omega-3 improves cardiovascular health. A study conducted on over 40,000 men revealed that men eating fish at least once a week had a 15% lower risk of heart diseases. Also, consuming eggs has shown to improve cholesterol levels and maintain weight.

A popular misconception is that protein consumption reduces bone density, this reduction is significantly lower in case of plant-based proteins as compared to animal-based protein. This misconception arises from the fact that calcium content in urine increases after consuming protein. A study showed that calcium content measured in urine is not an effective way to measure bone density and the reduced levels of calcium in urine in case of plant-based protein were mainly due to high potassium levels. Any changes in calcium content occur due to other constituents of food and diet and not just proteins.

  1. Absorption rates

No matter how much protein is contained in the food, what matters is how fast and how much of it can be absorbed by the body. Generally, animal-based proteins are similar to our protein and are easier to synthesis. Due to the absence of one or more essential amino acids, the synthesis of plant-based proteins is compromised. Animal protein also contains a higher concentration of Sulphur-containing amino acids, synthesis of which creates an acidic effect on the body which can be harmful.

Throughout years various methodologies have been used to determine the protein value of various foods. The most preferred system was proposed by Food and Agriculture Organization/World Health Organization (FAO/WHO) in 1991, called protein digestibility corrected amino acid score (PDCAAS), is determined by comparing the amino acid profile of the food in question against a standard amino acid profile. The score is a ratio of the amount of essential amino acids provided to the amount of protein digested. A score of 1 or 100 refers to 100% or more of the digested protein provides essential amino acid. Here is a list of PDCAAS score of some plant and animal-based protein:

ProteinDigestibility (%)PDCAAS
Cow's Milk95121
Beef 9892
Soy 9591
Data from FAO/WHO Expert Consultation 1990, European Dairy Association 1997, and Renner 1983.


A clear inference of this data leads one to believe that animal-based protein is absorbed much more efficiently than plant-based protein. However, when different plant-based proteins are consumed in a balanced combination of essential amino acids, the combined score can be equivalent to animal-based proteins. Despite having a high PDCAAS, the absorption rates might not necessarily be high. Thus, in a general sense, animal-based protein is absorbed faster and more efficiently but the difference in absorption rate is minimal when a variety of plant-based proteins are mixed to achieve a complete protein source. This difference may possibly be significant in the case of professional athletes but for a normal healthy lifestyle, both are equivalent.

  1. Derived supplementation

With increased awareness of health and fitness, more and more people are getting into to the habit of working out. The protein supplementation industry has benefitted the most from this change in perspective of personal health. It is a very common scene of seeing a person walk out of a gym, shaking a protein shake bottle. Naturally, the debate of animal protein vs plant protein has extended to post-workout supplementation as well. The most common type of protein supplement available is whey protein. Whey is derived from milk, as a byproduct while manufacturing cheese. A mixture of globular protein is isolated from whey and manufactured in powder form is sold.  Whey protein is a complete source of protein, known for its excellent ability to increase lean muscle mass. Gold Standard is one of the leading whey protein production brands, a 30g scoop of which contains 3g of carbohydrates, 1g of fat and 24g of protein.

However, since whey protein is derived from milk, it can cause digestive issues to anyone who is completely/partially lactose intolerant. Sensitivity to milk, which is generally not known, gets highlighted due to the concentrated nature of whey protein. In such a case, it causes bloating, indigestion and gas. Lactose intolerance leads to the development of plant-based protein supplements. These supplements are derived from brown rice, peas, and soy protein. Since they are completely lactose-free, they do not cause any issues related to its intolerance. However, most of these protein supplements are incomplete sources of protein, hence must be paired with other plant-based protein products. For instance, combining a scoop of pea protein powder with seeds like hemp, chia or flax can create a complete protein source. Soy protein is a much more effective alternative to whey protein as it is a complete source of protein. Bulk Supplements is a leading soy protein brand and each serving of 30g of the same contains 27g of protein.

  1. Effect on Environment

The production process of high protein foods causes adverse effects on the environment. With high requirements of processing, the carbon footprint of meat is very high. A study showed that the production of 1 kg of beef emits 26 kg of carbon dioxide. The environmental burden of plant-based proteins is much lower in comparison. For instance, production of 1 kg of lentils emits only 0.7 kg of carbon dioxide. Life Cycle Impact Assessment Techniques (LCIA) are used to quantify the effect of all stages of production. LCIA studies suggest the primary difference in animal and plant-based foods occurs at a primary economic production, like agriculture and fishing, and in processing foods. An experimental study based on soy protein and meat revealed that meat production was almost 20 times more harmful. The following table summarizes the effects on the environment caused by the production of soy protein and meat.

Relative Effect on Environment- Animal protein vs Plant protein

Environmentally relevant effectEffect of processed protein food based on soybeansRelative effect of meat protein production
Land Use16-17
Water Requirement14.4-26
Fossil Fuel Requirement16-20
Phosphate Rock Requirement17
Emission of acidifying substances1>7
Emission of biocides1>6
Emission of copper1>100

The results of such studies neglect the effect of the variety of agricultural soil and effects of biodiversity, hence do not provide an accurate real-life impact. However, they provide more than a rough estimate of environmental impacts and we can safely infer that animal-based protein is substantially more harmful than plant-based protein.


Final verdict

For an average individual, a plant-based diet with consumption of a variety of foods to ensure completeness is much more beneficial. It may not be as effective in short-term lean muscle gain but helps in the longevity of life and a general sense well-being. A plant-based diet is also less harmful to the environment, helping in sustaining the planet. However, complete elimination of animal-based protein might leave a deficiency of a few nutrients, which might cause the need of supplementation. Even in the case of supplementation, the quality and source of protein should be greatly considered. Allergies and sensitivities to ingredients must be analyzed and only then should it be consumed. For meat eaters, it is very important to reduce consumption of processed and red meat, while maintaining a balance of plant and animal-based foods. Thus rather than focusing on one protein, consuming a wide variety of foods can ensure a diet has a healthy balance of essential amino acids and other nutrients.

Sagar Papneja

For me, health is about sustainable living and consuming environmentally conscious food; I am a vegan.

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