Proteins exist in nearly all parts of our bodies. They are responsible for building, repairing, and maintaining various structures of the body including your muscles, bones, organs, skin, and hair. But as important as proteins are for the organism, they aren’t stored the way that other macronutrients are. Therefore, you need a steady supply of protein in your diet to ensure your body gets the proteins it needs.
So where do you get these proteins from? Are animal sources of protein the superior choice or do plant-based proteins offer better health benefits? Does it even matter where your protein is coming from as long as it’s meeting your goals? Read on as we delve into the world of proteins and take a look at the differences between animal and plant proteins, their benefits and pitfalls, and their effects on your health.
What is Protein and Why Do You Need it?
Let’s start with the basics. Protein is one of the three essential macronutrients (the others being carbohydrates and fats) that together form the building blocks of your body. They consist of smaller molecules called amino acids that link together in the form of chains to make complex structures. Although there are about 10,000 different combinations of amino acids that make up proteins, they are all variations of 22 basic amino acids.
The 22 basic amino acids are further divided into two categories - essential and non-essential. Your body can produce the 11 non-essential amino acids on its own. However, the remaining 9 essential amino acids are the ones that your body cannot make on its own and must come from the food you eat. Essential amino acids can be sourced from both animal and plant sources (hence the debate of which source is better) but more on that later.
First, let’s discuss how much protein your body needs on a regular basis to function properly.
How Much Protein Do You Need?
According to the National Academy of Medicine, adults need about 0.8 grams of protein for every kilogram of body weight per day. That is about 7 grams for every 20 pounds of weight. So if you weigh around 140 pounds, you need to consume at least 50 grams of protein each day to stay healthy. Proteins can make up anywhere from 10% to 35% of your total caloric intake each day.
What are Complete Proteins?
Remember the 9 essential amino acids that need to be sourced from your food? Well, it is possible to get all nine from the same source. Proteins that carry all nine essential amino acids are called complete proteins. All animal proteins are complete proteins. Some plant proteins like soy are also complete proteins since they contain all the essential amino acids.
What are Animal Proteins?
Animal proteins, as the name indicates, are proteins that we get from animal products. These include direct animal sources like meat, fish, chicken and all their derivatives like eggs, dairy, and more. Animal proteins are considered the highest-quality proteins since they are similar to the proteins found in the human body. Since they are complete proteins, you can basically get all the essential amino acids you need through a single source of animal protein.
Popular Sources of Animal Proteins
Here is a list of some of the popular sources of animal proteins.
- Beef, pork and other red meat
- Chicken, turkey, ducks and other poultry
- Dairy products like cheese, milk and whey
- Fish and seafood
What are Plant Proteins?
Plant proteins refer to the proteins we get from fruits, vegetables, grains, nuts, seeds, legumes, and any derivatives of these products. According to the FDA, all plant-based proteins should offer at least 5 grams of protein per serving. Plant proteins are generally considered incomplete proteins since they don’t offer all the essential amino acids in a single source. This doesn’t mean that you can’t get all essential amino acids from plant proteins. It just means that you would need to combine different protein sources to get a complete amino acid profile in your diet.
Popular Sources of Plant Proteins
Here is a list of some popular sources of plant proteins.
- Legumes like beans, lentils, soy, chickpeas, peas, peanuts, etc.
- Walnuts, pecans, almonds, hazelnuts and other nuts
- Avocados, hemp seeds, quinoa, rice (in combination with beans)
Animal Protein vs Plant Protein - The Ultimate Showdown
Now that you have an idea of what animal and plant proteins are, let’s dive into what makes them so different from each other.
The basic difference between animal and plant proteins is the amount of protein compared to carbs and fats. Animal proteins generally have a larger proportion of protein relative to carbohydrates, than plant protein sources.
To get a better idea of what this entails, a 4oz cut of lean protein (animal) such as chicken or beef will offer about 20-25 grams of protein while the same amount of tofu, one of the densest plant protein sources, will offer only about 10 grams. You will need to consume double the quantity of tofu to get as much protein as 4oz of chicken.
No matter what the source, proteins don’t exist in a void. Every single source of protein also comes with a bunch of other nutrients that cannot be ignored when comparing one source to the other. A bird’s-eye view of the different nutrients in animal-based proteins highlights the following:
Vitamin B12: This vitamin is only found in animal sources like fish, poultry, meat, and dairy products. Vitamin B12 deficiency can lead to serious health problems.
Vitamin D: This vitamin is found both in animal and plant sources of protein. However, animal sources of vitamin D like oily fish, eggs, and dairy are considered to have a type of Vitamin D that is better for your body.
EPA: Eicosapentaenoic acid is an omega-3 fatty acid that is found in fatty fish, seafood, and fish oil. It is difficult to get from plant-based sources and is essential for reducing inflammation and improving certain mental conditions like depression.
Heme-Iron: Heme-iron is a large source of dietary iron because it is more easily absorbed by our body. Red meat has the highest density of heme-iron.
Zinc: Zinc is another important nutrient that is largely found in animal protein sources like pork, lamb, and beef. It helps make your immune system stronger and improves your metabolism.
DHA: Docosahexaenoic acid is another essential omega-3 fatty acid that is largely found in animal sources like fatty fish, fish oil, algae, and seafood. It is essential for developing the structural components of your brain and nervous system. It is also very important during pregnancy and lactation.
Plants also come chock-full of some amazing nutrients that offer great health benefits. Some of them include:
Phytonutrients: Plants contain thousands of natural chemicals that give them their color, flavor, and smell. However, they also have a number of protective functions that are transferred to your body when you consume plant sources of protein. These phytochemicals can help reduce oxidative damage, delay aging, get rid of inflammation, and prevent certain kinds of cancers. Phytonutrients are the reason why plants are called superfoods. You can get phytonutrients from fruits, vegetables, whole grains, nuts, beans, and more.
Antioxidants: Plants are the largest source of natural antioxidants like polyphenols, carotenoids, and vitamins. These antioxidants provide a number of benefits to the human body including reducing inflammation, fighting off bacteria and viruses, delaying aging, and preventing cancer. Spinach, potatoes, avocadoes, asparagus, and kale are particularly rich sources of antioxidants.
Fiber: One stand-out nutrient that animal sources simply don’t have is fiber. You can only get fiber from plant sources like vegetables, legumes, lentils, grains, and more. Fiber is essential to keep your digestive system clean and healthy. It helps flush out cholesterol and other harmful carcinogens from your body.
Vitamins: Plants are full of essential vitamins like B, C, A, E, and K. All of these vitamins have a number of health benefits including reduced risk of heart disease, improved brain function, better colon health, delayed aging, and more.
Weight loss is one of the main reasons why protein-based diets are enjoying their popularity. Studies show that a protein-rich, low-carb diet can help you reduce weight. Protein is also known to inhibit your appetite as eating more protein can make you feel ‘fuller’ as opposed to carbs.
A study published on the National Library of Medicine shows that women who increased the ratio of protein in their total caloric intake ate fewer calories per day and lost more weight. However, there isn’t much research that indicates which kinds of protein sources will help you lose more weight.
For argument’s sake, we can say that since high-protein, low-carb diets show the most promise where weight-loss is concerned, animal proteins may have the edge over plant proteins. At the same time, research shows that vegetarians or vegan eaters tend to be leaner than people who eat meat, which might be attributed to higher consciousness of eating healthy foods in general.
In other words, it is hard to say conclusively which type of protein is better for weight loss. In the end, how much weight you lose depends on a number of factors like your weight, physical activity, any pre-existing medical conditions, and the complete type of diet you follow, not just protein.
Muscle gain isn’t just for bodybuilders. A healthy human body needs a minimum 20-30 grams of protein throughout the day to build and maintain muscles. This amount becomes more significant as we age since muscle tissue breaks down faster with age which in turn slows down your metabolism. Less muscle mass can also increase the risk of diabetes, osteoporosis, and low energy levels.
Protein intake is essential for muscle building. Animal sources of protein usually rank higher in the density and type of proteins that are needed to build muscle. For instance, milk protein is easily absorbed by the body and promotes lean muscle growth. Animal proteins are also complete proteins as opposed to plant ones that are missing certain amino acids. While a vegan diet isn’t going to cause any amino-acid deficiencies, in terms of muscle building, animal proteins provide results with less effort.
The biggest advantage of consuming plant proteins is that they contain fiber. Fiber is essential for good digestive health. When you look at plant protein sources like beans and whole grains, they basically offer two benefits in one; they are not only rich sources of protein but also have the right amount of fiber.
One of the biggest caveats of high-protein diets is that they can cause constipation and delay digestion. However, with plant proteins, you don’t really have to worry about any of that. But what about the additional carbs? Well, all plant protein sources have carbs in them but they range in quantity, which can be addressed with proper meal planning.
Since animal sources of protein have virtually no carbs or fiber, they don’t aid in digestion at all.
Amino acids are not just used by your body to build and maintain different structures but are also used to make certain hormones. Here is a brief look at how different types of protein sources affect three main hormones in your body:
Estrogen: A hormone that uniquely affects women of all ages, estrogen reacts differently to different types of protein sources. A meat-heavy diet is linked to a higher BMI and weight gain. Red meat is known to increase estrogen levels causing a hormonal imbalance in women. The saturated fats in animal proteins can also elevate estrogen levels and increase the chances of breast cancer.
Conversely, people who rely on plant proteins or follow a vegan diet are shown to excrete more estrogen than meat-eaters thus reducing their estrogen levels. The high amount of fiber in plant proteins is also linked with reducing the chances of breast cancer.
Thyroid: Thyroid issues are mainly caused by protein sources that contain gluten and mercury. While the former is more prevalent in plant sources, the latter is mainly found in some fish (tuna, swordfish, shark). Both gluten and mercury can cause hypothyroidism in women.
Insulin: Fiber plays an important role in stabilizing our blood sugar levels, preventing insulin resistance, and reducing the risk of type 2 diabetes. Since animal proteins don’t have fiber, a meat-rich diet may put you at risk. On the other hand, the inflammation-reducing properties of certain types of meat may actually be beneficial in keeping all these conditions at bay as well.
Other Health Considerations
Processed meat and other animal proteins are linked to a higher risk of heart diseases. Some animal proteins are also rich in saturated fats that increase cholesterol and may lead to obesity and higher blood pressure.
On the flip side, certain plant sources like legumes have high levels of antinutrients like lectins that may can cause intestinal problems. Processed soy can cause hormonal imbalances and increased dependence on omega-6 fatty acid foods like nuts may increase the risk of developing depression.
In short, both plant and animal proteins come with their fair share of pros and cons when it comes to your health. It is always better to take a balanced diet and to consult a certified dietician before making any drastic changes to your diet.
The Final Word
The debate of animal vs plant protein has been a hot topic for a while now and will remain one for years to come. While there are convincing supporting arguments for either source of protein, there is no definitive winner here. Your choice of protein will depend on a number of factors and may keep changing as per your changing needs. Hopefully, this article can help you make an educated decision about your dietary needs.