The Truth About Protein (and where to get it!)

What is the first thing you think of when people talk protein? Do you associate a high-protein diet with building huge muscles and “bulking up”?

Well this is not entirely accurate and it is important to understand that protein is an essential part of the human diet that helps to build, repair, and maintain the body's structures. Despite protein existing throughout the body, it does not store protein like it does with other macronutrients, so it is essential we obtain protein through the diet. We can increase our protein intake through the consumption of BOTH animal and plant proteins, however it is important to understand the DIFFERENCES between these types of protein to ensure a healthy diet.

Need a few good reasons to add more protein in your diet? 

  • It is a component of EVERY cell in your body (your hair and nails are mostly made up of protein)
  • Your body needs it to build and repair tissue 
  • Helps reduce muscle loss and build lean muscle
  • Helps maintain a healthy body weight by curbing hunger and leaving you feeling fuller for longer
  • Your body needs it to make hormones, enzymes and other body chemicals

Plant protein vs animal protein

So, which is better? Animal or plant protein? 

The short answer is you don’t have to pick one over the other. Rather than focusing on a single type of protein, it may be better to focus on eating a wide variety of foods to provide your body with a balance of amino acids and other vital nutrients. 

However, if we want to get a bit more complex, it all comes down to the aminos! All proteins are made up of amino acids, although the type and amount of each amino acid varies based on the protein source. The primary difference between animal and plant proteins is their amino acid profiles. Animal protein sources are considered ‘complete’ protein sources as they contain ALL the essential amino acids whereas plant protein sources are considered ‘incomplete’ as they lack one or more of the essential amino acids that the body needs to work effectively. These amino acid profiles control the rates at which the absorbed amino acids are utilised within the body. 

Animal protein is much more similar to the proteins found in our body’s and are therefore used more readily and rapidly in comparison to plant proteins as these may take longer for the body to digest and use. Animal and plant proteins also differ in the nutrients each provide. Animal protein sources are higher in nutrients such as heme-iron, vitamin B12, vitamin D, omega-3 fatty acid DHA and zinc. Plant proteins on the other hand, are high in fibre and have antioxidant and anti-inflammatory properties of which are absent from animal protein sources. 

Eating more plant protein may also improve a person's overall health according to the Australian Dietary Guidelines. Studies indicate that a diet high in plant protein has been linked to a lower risk of diabetes, heart disease and obesity. Animal products usually contain saturated fat and higher levels of cholesterol in comparison to plant sources of protein and may contribute to chronic disease such as heart disease.

Amino acids explained

So, what are amino acids? Sounds complicated, right? Well Amino acids are basically the building blocks of protein. The body digests the proteins found in food and then breaks them down into amino acids. They are vital for bodily processes such as the protein synthesis, tissue repair and nutrient absorption. Some studies even suggest amino acids may also improve mood, athletic performance and weight loss.

The body needs 20 different amino acids to function properly. Despite all 20 being important for your health, online nine amino acids are ‘essential’. These are isoleucine, histidine, lysine, leucine, phenylalanine, threonine, methionine, tryptophan and valine. These differ from ‘non-essential’ amino acids as they cannot be made up by your body and must be obtained through the diet. For optimal health, your body needs all the essential amino acids in the right ratios. This can be achieved through a balanced diet of consuming animal and plant-based protein sources. Having the right balance of amino acids can help build muscle and allow your body to recover rapidly from exercise.

Best sources of plant-based protein

Most plant proteins are incomplete, which means they are lacking at least one essential amino acid. However, the right plant-based foods can be amazing sources of protein and other nutrients, usually with fewer calories in comparison to animal products! 

The following plant-based foods have a high-protein content: 

  • Tofu and Tempeh- These soy products are among the richest sources of protein with 10-19g of protein per 100g. They also offer good amounts of iron, calcium, magnesium, phosphorus and probiotics.
  • Edamame- Contain a high 10-19g of protein per 100g as well as being rich in folate, vitamin K and fibre.
  • Quinoa- With 11g of protein per cooked cup (240 ml) these are complete sources of protein. Its also a great source of complex carbohydrates, iron, fibre, magnesium, phosphorous and manganese.
  • Lentils- At 18g of protein per cooked cup (240ml), lentils are a great source of protein as well as being rich in folate, manganese and iron. Furthermore, they contain good amounts of antioxidants and have been shown to feed the good bacteria in your colon, promoting a healthy gut.
  • Spirulina- This blue-green algae provides you with 8g of complete protein per 30ml. In addition to covering 22% of your daily iron and thiamin requirements, it also contains good amounts of magnesium, potassium, riboflavin and some essential fatty acids. Furthermore, it has powerful anti-oxidant, anti-inflammatory and anti-cancer properties making spirulina a nutritional superfood.
  • Almonds- With 16.5g of protein per ½ cup they also are rich in vitamin E, which is great for the skin and eyes.
  • Chia seeds- this is a complete source of protein that is rich in fibre and omega-3 fatty acids. At 6g of protein and 13g of fibre per 35g as well containing iron, selenium, calcium and magnesium, chia seeds definitely make the list.
  • Hemp seeds- Contains 10g of complete and easily digestible protein per 28g. Also rich is iron, calcium, magnesium, selenium and zinc! Hemp seeds are also a great source of omega-3 and omega-6 fatty acids and has been shown to help reduce inflammation.
  • Chickpeas- With 15g of protein per cooked cup (240 ml) they are also excellent sources of complex carbs, fibre, iron, folate, phosphorus, potassium and manganese. They have also been shown to decrease cholesterol, help control blood sugar levels and reduce belly fat.

Please note that it is important for individuals who follow a vegetarian or vegan diet mix their protein sources to ensure they are consuming all the essential amino acids. Some plant food sources, such as soy beans, quinoa and chia seeds, are complete proteins meaning that they contain all nine essential amino acids that humans need. However, others are lacking some of these amino acids, so eating a varied diet is important!

Comparison of different protein powders

Protein powders are a quick and easy way to ensure your body is nourished and satisfied. But how do we know what protein powder we should be having? With there being so many options to choose from these days it can be overwhelming knowing what protein might work best for your body. However, like many other supplements, each type of protein has its pros and cons and it really comes down to what you are looking to get out of the product and understanding what products works best for you. There are a number of reasons people use protein powders such as wanting to lose weight, enhance athletic performance, build muscle mass and improve overall health and wellness.

Here a few popular protein powders discussed:

  • WHEY PROTEIN

Whey protein is usually the go-to option for gym junkies wanting to build muscle mass and tone. Whey protein is absorbed faster and contains glutamine which aids in muscle growth which may be the reason for its popularity. Whey is higher in branched chain amino acids (BCAA), essential amino acids and non-essential amino acids as well as containing a number of vitamins and minerals. However, this product is often highly processed as well as being high in sugar and artificial sweeteners (like sucralose). Consuming large amounts of this protein may pose health risks. Excess consumption of whey protein may lead to weight gain, kidney stress, bloating and other digestive issues that has not been seen in plant-based protein powders. This product is NOT suitable for vegans or those that are lactose intolerance due to the main component of casein being derived from milk. 

  • SOY PROTEIN

Soy protein is a type of plant-based protein that is high in amino acids when unprocessed. It contains a complete amino acids profile giving it an advantage over other plant proteins. Soy protein is often a good choice for individuals with milk or lactose allergies and is also vegan friendly. Some benefits of soy protein include delaying menopause, lowers blood pressure, increases muscle strength and lowers cholesterol. The concerns with soy are often hormone related as they may lead to hormonal imbalances - and really only apply to GMO produced soy.

Non-GMO, water-washed minimally processed soy is one of the best quality protein sources available, with little (if any) downsides.

  • PEA & RICE PROTEINS

Pea and rice proteins are 100% plant-based and both are a highly digestible, hypo-allergenic and vegan-friendly option to other proteins. The BCAA’s are great for weight loss and maintaining muscle mass. They are excellent sources of energy and encourage high metabolism which boosts digestion as well as regulates appetite and curves cravings. They are often one of the cheapest and most affordable protein options which is ideal if you do not want to spend crazy amounts to increase your protein intake. The sugar and calorie contents are extremely low however, this may suggest they are not as tasty as other proteins (such as whey protein) which have a higher sugar content. They both have high protein and low carbohydrate content but incomplete amino acid profiles. They are often mixed together for this reason as they provide more essential amino acids when combined.

  • HEMP PROTEIN

Hemp protein powder is a vegan-friendly, complete source of protein packed full of minerals, antioxidants, fibre and healthy unsaturated fats. Hemp protein is approximately 91-98% digestible meaning your body can use almost all of the amino acids for vital bodily function such as repair and maintenance! Its best to look for hemp protein powders that are made from cold-pressed seeds and free from heat-processing, as this can reduce the digestibility of the protein by about 10%. Hemp seeds are a great source of fibre which have been linked to many health benefits such as improved blood sugar, reduced risk of cancers and healthier gut bacteria. Hemp protein powder is generally safe for everyone however the relatively high amounts of fibre may cause some individuals to experience bloating or diarrhoea if too much is consumed too quickly.

Daily protein requirements-

How much protein should you be eating each day? Well the “right” amount of protein for any one individual depends on a number of factors including age, gender, weight, physical activity level. The Australian Dietary Guidelines suggest consuming 2-3 serves of protein every day with 15-25% of our daily energy needs coming from protein! The recommended intake for adults aged 19-70 years is about 64g for men and 46g for women. However, keeping on the lower-end of the recommended intake (15%) is adequate to meet your requirements so long as you are getting in all the essential amino acids.

When should you be consuming protein? EVERY MEAL! Including protein with each meal helps increase satiety and effectively fuels muscle growth. Spreading your protein intake evenly throughout the day is an ideal way to consume protein! It is also important to consume protein after weight-bearing exercise as it is essential for protein synthesis and muscle repair. Protein requirements are significantly increased in individuals who are physically active as well as in older adults or those recovering from injury.

Dangers of eating too much animal protein

So, if protein has so many amazing health benefits why would it be dangerous to consume too much? Well, like all things in life, moderation is key. Yes, protein is an essential part of a healthy diet and helps build and repair bones, muscles and organs but it is important to not exceed the recommended intake and be aware of the potential health risks. Excess protein in the body is related to a number of health concerns, particularly if you follow a high animal-protein diet for an extended period of time. Here are a few reasons to not exceed the animal-protein intakes:

  • Weight gain

This excess protein will basically just contribute to excess calories and be stored as fat in the body, eventually leading to weight gain – not what we want, right? Animal protein also contains more calories and less (if any) fibre in comparison to plant protein. Fibre is strongly associated with weight loss and the lack of fibre in animal protein sources may contribute to weight gain.

  • Kidney damage

Consuming a high animal-protein diet for an extended period of time may increase your risk of kidney damage and may lead to renal disease. This is due to the excess nitrogen found in amino acids and your kidneys having to work harder to get rid of the extra nitrogen and waste products of protein metabolism. This extra stress on the kidneys and declining kidney function has been linked to animal protein, animal fat and cholesterol. No association has been found between kidney function decline and intakes of plant protein, with virtually no such stress being placed on the kidneys. 

  • Heart disease

Consuming high amounts of animal products such as red meat and full-fat dairy products as part of a high-protein diet may lead to heart disease or other heart-related complications. This is primarily due to increased intakes of saturated fat and cholesterol found in these animal products.

  • Increased cancer risk 

High-protein diets have often been associated with an increase in cancer. Animal protein consumption triggers the release of insulin-like growth factor 1 (IGF-1), a cancer promoting growth hormone. If these levels remain too high, our cells constantly receive a message to continuously grow and divide! The more IGF-1 in our bloodstream means a higher risk for developing some cancers. Studies actually suggest a decreased cancer risk for individuals who do not eat meat! This is believed to be due to a lower intake of harmful hormones, carcinogens and saturated fat found in animal meats.

  • Osteoporosis

High intakes of animal protein has been associated with increased urinary excretion of calcium. Animal protein tends to suck calcium from the bones, potentially resulting in muscle loss and weakened bones. Studies have even suggested a correlation between high dairy and animal protein consumption and higher incidences of bone fractures. 

  • Lacking other important macronutrients

This excess consumption of protein will also limit your intake of all other macronutrients that are essential in a healthy diet. A balance of the three macronutrients (carbohydrates, protein and fats) provides the body with unique nutrients. Restricting one macronutrient means you are missing out on the vital benefits they provide for your body. Similarly, going overboard on another nutrient, such as protein, results in potential health risks. Remember the body thrives best on a balanced diet of these macronutrients!

Take home message!

Hopefully you now have a better understanding about animal and plant proteins and the health benefits and potential risks of each. Rather than focusing on a single type of protein, it is important to focus on eating a wide variety of foods to ensure you get a balanced diet full of vital nutrients! Plant-protein diets based on high intakes of fruits, vegetables and whole grains are associated with lower risk of chronic disease and less adverse health risks in comparison to animal protein products. When choosing animal protein always opt for high-quality, unprocessed sources. When choosing plant protein be sure to eat a variety of foods to ensure you are consuming all the essential amino acids and vital nutrients. 

 

By Gina Holdsworth, 3rd Year Nutrition Student.

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