Protein is all the buzz in the fitness scene. It’s plastered on every health product shelf, from protein-packed yogurts to those fitness influencer meal preps bragging about their protein punch. Everyone from gym rats to nutrition gurus can’t get enough of it.

But protein isn’t just another health trend. It’s a crucial part of your diet, delivering essential amino acids your body can’t produce on its own. Amino acids aid in building new tissue, maintaining older tissue, and even chipping in to produce vital enzymes, antibodies, and hormones. And let’s not forget their role as the body’s shipping department, shuttling around all the good stuff like vitamins, minerals, and fats through your bloodstream, all-in-all maintaining homeostasis of the vessel you call your body.

Now, here’s the big debate that’s got everyone talking: which type of protein is superior – plant or animal?

Well, let’s break it down and try to understand the science behind each viable option.

Animal-Based Protein Diet

The quality of dietary protein is determined by its essential amino acid profile and is assessed using the Protein Digestibility Corrected Amino Acid Score (BIG WORD, let’s just call it the PDCAAS), which considers both human nutritional requirements and the protein’s digestibility, absorption, and retention in the body. A PDCAAS score below 1 indicates suboptimal protein quality, while a score of 1 or higher is considered optimal for fulfilling the body’s essential protein functions. (Berrazaga et al., 2019)

Animal protein is considered “high quality” due to its provision of all nine essential amino acids in ample amounts, essential for muscle growth, repair, and overall physiological function. Moreover, most animal-based proteins boast a PDCAAS close to or at 1.00, indicating optimal protein quality (FAO, 2013). This high PDCAAS score suggests superior bioavailability, signifying that a larger quantity of the nutrient is absorbed and utilised after consumption for normal physiological function (Lim et al., 2021). In simpler terms, opting for animal protein provides more bang for your buck.

However, excessive consumption of animal protein, especially from processed and red meats, has been associated with potential health risks, including an increased risk of cardiovascular disease, cancer, and other chronic conditions due to their higher saturated fat content and dietary cholesterol contents. However, it must be noted unprocessed red meat consumption has smaller effects on type 2 diabetes and little to no effect on coronary heart disease. (Micha, Michas and Mozaffarian, 2012)

Plant-Based Protein Diet

Plant-based protein diets offer a multitude of benefits, especially for individuals seeking a sustainable approach to nutrition. Consider the array of options: beans, lentils, tofu, tempeh, nuts, seeds, and whole grains. These sources not only provide relatively ample protein but also offer a diverse array of essential nutrients such as fiber, vitamins, minerals, and antioxidants. It’s a balanced and nutrient-rich foundation for any diet. (Turner-McGrievy, Mandes and Crimarco, 2017)

Plant protein sources are often lower in saturated fat and cholesterol compared to animal protein, making it a healthier option for your cardiovascular system reducing the risk of chronic cardiovascular diseases. (Dinu et al., 2016)

In the context of sports or training, plant proteins may be deficient in certain essential amino acids compared to animal proteins. Additionally, their PDCAAS scores often fall below 1.00, indicating suboptimal utilization of protein. However, it’s worth noting that combining various plant-based protein sources can boost PDCAAS scores above 1.00. This means that any essential amino acids lacking in one protein source are complemented by another source that contains them. With careful planning, it’s possible to ensure an adequate intake of all essential nutrients. (Lim et al., 2021)

Comparison between the two protein sources for hypertrophy, strength, performance, and recovery

Both animal and plant proteins contribute to an increase in absolute and percent lean muscle mass, although animal protein tends to yield a more significant gain. This disparity may be attributed to the superior protein quality of animal sources, stemming from their optimal amino acid profile and enhanced bioavailability (Campbell et al., 2015).

However, plant-based proteins, while beneficial, are often deficient in specific essential amino acids. This deficiency can lead to the redirection of amino acids towards urea (urine) synthesis rather than muscle building, potentially limiting muscle growth (van Vliet et al., 2015). Additionally, the presence of fibre in plant-based foods can hinder their bioavailability, making it challenging for the body to fully digest and utilize the protein (Gibson et al., 2017).

While animal protein has been associated with a statistically significant increase in percent lean mass, it’s important to note that the clinical significance of this increase remains uncertain. Furthermore, research indicates that the impact of protein source on muscle strength varies across different outcome measures, with inconsistencies observed (Lim et al., 2021). However, it’s essential to recognise that strength gains are influenced by numerous factors, making it challenging to definitively determine which protein source is superior for increasing strength. Ultimately, resistance exercise training emerges as the primary driver of muscle development, overshadowing the choice between animal and plant-based proteins.

Conclusion

So, which is better? well if your goal is muscle building, then arguably, the evidence points towards an animal-based protein diet. If you’re more ethical and prefer to contribute to a lower environmental impact, or are trying to lose weight, then arguably, opting for a plant-based protein diet is better.

We advocate for finding a harmonious balance between the two protein options, just like the concept of yin and yang. This balanced approach allows you to enjoy the advantages of animal-based protein diets, such as obtaining all essential amino acids, while also addressing potential deficiencies in iron, vitamin B12, and other micronutrients. Additionally, incorporating plant-based protein sources enables you to reap the health benefits they offer. This balanced approach not only optimises nutrient intake but also promotes overall health and well-being. However, it’s important to consider individual preferences and any religious or ethical considerations regarding meat consumption.

As always, taking a thoroughly researched and balanced approach empowers you with the knowledge needed to make informed dietary choices. It’s essential to recognise that every dietary approach comes with its own set of pros and cons. Therefore, carefully considering these factors is crucial when deciding what to include in your daily meals. By weighing the advantages and disadvantages of various dietary options, you can tailor your eating habits to best support your health and lifestyle goals.

References

1. Berrazaga, I. et al. (2019) ‘The Role of the Anabolic Properties of Plant- versus Animal-Based Protein Sources in Supporting Muscle Mass Maintenance: A Critical Review’, Nutrients, 11(8), p. 1825.
2. FAO (2013) Dietary protein quality evaluation in human nutrition Report of an FAO Expert Consultation, pp. 1–66. Available at: https://www.fao.org/ag/humannutrition/35978-02317b979a686a57aa4593304ffc17f06.pdf (Accessed: 22 April 2024).
3. Lim, M.T. et al. (2021a) ‘Animal Protein versus Plant Protein in Supporting Lean Mass and Muscle Strength: A Systematic Review and Meta-Analysis of Randomized Controlled Trials’, Nutrients, 13(2), p. 661. Available at: https://doi.org/10.3390/nu13020661.
4. Micha, R., Michas, G. and Mozaffarian, D. (2012) ‘Unprocessed Red and Processed Meats and Risk of Coronary Artery Disease and Type 2 Diabetes – An Updated Review of the Evidence’, Current Atherosclerosis Reports, 14(6), pp. 515–524. Available at: https://doi.org/10.1007/s11883-012-0282-8.
5. Turner-McGrievy, G., Mandes, T. and Crimarco, A. (2017) ‘A plant-based diet for overweight and obesity prevention and treatment’, Journal of geriatric cardiology : JGC, 14(5), pp. 369–374. Available at: https://doi.org/10.11909/j.issn.1671-5411.2017.05.002.
6. Dinu, M. et al. (2016) ‘Vegetarian, Vegan Diets and Multiple Health outcomes: a Systematic Review with meta-analysis of Observational Studies’, Critical Reviews in Food Science and Nutrition, 57(17), pp. 3640–3649. Available at: https://doi.org/10.1080/10408398.2016.1138447.