Can Vegans Get Enough Protein?

A common criticism to the vegan diet is that they lack a sufficient amount of protein. In fact, if you’re vegan, its likely you’ve been pestered about this by well-meaning friends and family members at some point.

You may have heard comments such as: ‘I’d like to go vegan but I love my protein too much’, ‘there’s not enough protein in rabbit food’ or ‘you can’t gain muscle mass eating only plants’.

So, the age-old question is, can vegans get enough protein?

Let’s bust a few myths around how you can eat protein sufficient meals on a whole foods plant-based diet.

First of all, we’ll take a look at how much protein we actually need to eat each day, so we have a baseline to work from.

Our protein needs

Under normal circumstances, we need less than 1 gram (g) of protein per kilogram of our body weight daily (1).

However, it’s important to note that our protein needs do vary at certain points during our life. For example, our needs would increase during times of growth and/or repair such as during childhood, pregnancy, breastfeeding, athletic training or if you are ill or injured. Even in these cases, our needs are still often less than people assume.

Did you know that protein deficiency is actually very rare in healthy adults who are consuming enough food (aka adequate calories)? (1)

To calculate our daily protein needs (as a health adult) the equation is:

0.9 x kg (body weight)

We also need to factor in that digesting plant foods may be 10% tricker. Even with that considered for the average daily requirement for a plant-based diet, we still only need 0.9.

Let’s say for example that you weigh 70kg. You would roughly need 63g protein daily as 70x0.9=63.

Based on Australian national guidelines, males on average need 64g protein daily and women need 46g daily. (2,3)

Now, lets put that into perspective. One cup of firm tofu contains approximately 30g protein…

So, how much protein does the average adult consume?

According to the National Nutrition Survey, Australian men consume around 109g of protein each day while women consume 74g daily. (5)

As you can see, this is well above recommendations!

Meanwhile, large Australia studies show that vegan men consume roughly 81g of protein daily and vegan women consume 54g protein daily. So yes, while this is technically ‘less’ than the omnivores, it is still well within the recommend 64g and 46g daily! (7-8)

Maybe you’re thinking, so what? You can never have too much protein, right?

Well actually, that’s not quite true!

In fact, excess protein consumption has been linked to kidney and bone damage, along with certain cancers. (6, 9-12) In addition, high protein diets – especially those based on animal protein such as meat and dairy – are often high in fats. For this reason, excess protein consumption has been linked to an increased risk of cancer, diabetes and heart disease. (13-16) Therefore, getting the right amount is important. As with everything, a healthy balance is the key.

Vegan Sources of Protein

All natural whole foods are a combination of fat, protein and carbs, meaning that even fruit has protein in it.

It was also once believed that vegans and vegetarians needed to combine different plant proteins at every meal. For example, eat beans with rice or nuts with tofu. Science has now proven that this is not true!

So, what exactly is a protein? We use protein all throughout the day to build muscle, for our immune systems, for our hormones and to make chemical reactions. A protein is a string of amino acids, which we think of as beads on a string. There are about 21 amnio acids (or beads), and 9 of them are considered essential - which means we can’t make them, we have to get them from what we eat.

A salmon protein is a different string of beads compared to a tofu or a peanut string of beads. Each food has a different set of coloured beads.

You may have heard of complete, high-quality protein. This is a protein that contains all 9 of those amnio acids. These four proteins are:

-          Quinoa

-          Hemp seeds

-          Soy beans

-          Amaranth

Other plant foods are missing one or two of these amnio acids. However, this is OK because when we eat foods, including plants, the protein from them gets broken down in our body and transported to what’s called an ‘amino acid pool’. (1, 6) You can think of it like a recycling plant. We then use the amino acids in this pool to re-make all the new proteins our body needs - kind of like recycling used paper to make new products such as clothing or magazines.

This means that as long as we eat a variety of plant foods daily, including veggies, grains, legumes and fruit – you can make all the protein your body needs to function and thrive!

Plant Power

Another benefit of getting protein from whole plant foods is that wholegrains, legumes, veggies and fruit all contain fibre, which most Australians are actually not getting enough of! (1, 5) These foods also contain beneficial plant nutrients (phytonutrients) that promote health in numerous ways and protect against cellular damage. (6) This magic combo of fibre and phytonutrients is why eating plant proteins rather than animal proteins has been shown to reduce the risk of ‘irreversible’ chronic diseases such as diabetes and heart disease. (17-18) What’s more, there is an amnio acid found in seeds called ‘tryptophan’ that helps make serotine, the hormone that keeps us chilled and calm.

In addition, fibre slows down digestion and makes the food bulkier in our stomach. This helps us feel fuller and more satisfied for longer. The longer digestion time will also help to stabilise blood sugars. And soluble fibre helps draw in cholesterol and kick it out of the body. 

If you’re concerned that you are not meeting your daily protein needs, you may find it helpful to book an initial consultation with one of our dietitians to learn more. This is a great starting point and is held online from the comfort of your home or office. If you would like to join our appointment waiting list, please drop us an email at: hello@thegreenmind.com.au

By Amber Sewell-Green
Vegan/Plant-Based Dietitian (APD) and Nutritionist (AN)

References:

1. Marsh K, Munn E, Baines S. Protein and vegetarian diets. The Medical Journal of Australia. 2012;1(2):7-10.

2. NHMRC. Nutrient Reference Values for Australia and New Zealand: Protein [Internet]. NHMRC publications; 2006 [cited 1 March 2017].

3. Joint WHO/FAO/UNU Expert Consultation. Protein and amino acid requirements in human nutrition. World Health Organ Tech Rep Ser 2007; 935: 1-265.

4. FSANZ. NUTTAB 2010 Online Searchable Database: Tofu (soy bean curd), firm, as purchased. Foodstandards.gov.au. 2017 [cited 3 March 2017]. Available from: http://www.foodstandards.gov.au/science/monitoringnutrients/nutrientables/nuttab/Pages/default.aspx

5. Australian Bureau of Statistics. National Nutrition Survey. Selected Highlights, Australia, 1995. Canberra: ABS, 1995: 20. (ABS Cat. No. 4802.0.)

6. Mahan L, Escott-Stump S, Raymond J, Krause M. Krause’s food & the nutrition care process. St. Louis, Mo: Elsevier/Saunders; 2012.

7. Wilson AK, Ball MJ. Nutrient intake and iron status of Australian male vegetarians. Eur J Clin Nutr 1999; 53: 189-194.

8. Ball MJ, Bartlett MA. Dietary intake and iron status of Australian vegetarian women. Am J Clin Nutr 1999; 70: 353-358.

9. Butler LM, Sinha R, Millikan RC, et al. Heterocyclic amines, meat intake, and association with colon cancer in a population-based study. Am J Epidemiol. 2003;157:434-445.

10. Knight EL, Stampfer MJ, Hankinson SE, Spiegelman D, Curhan GC. The impact of protein intake on renal function decline in women with normal renal function or mild renal insufficiency. Ann Int Med. 2003;138:460-467.

11.  Barzel US.  Excess dietary protein can adversely affect bone.  J Nutr. 1998 Jun;128(6):1051-3.

12. Abelow B.  Cross-cultural association between dietary animal protein and hip fracture: a hypothesis.  Calcific Tissue Int 50:14-8, 1992.

13. World Cancer Research Fund/American Institute for Cancer Research. Food, Nutrition, and the Prevention of Cancer: A Global Perspective. World Cancer Research Fund/American Institute for Cancer Research, Washington, D.C., 1997, pp. 216–251.

14. Bingham SA, Luben R, Welch A, Wareham N, Khaw KT, Day N. Are imprecise methods obscuring a relation between fat and breast cancer? Lancet. 2003;362:212–214.

15. Cho E, Speigelman D, Hunter DJ, Chen WY, Stampfer MJ, Colditz GA, Willett WC. Premenopausal fat intake and risk of breast cancer. J Natl Cancer Inst. 2003;95:1079–85.

16. Report of a Joint WHO/FAO Expert Consultation. Diet, Nutrition and the Prevention of Chronic Diseases. WHO Technical Report Series 916, 2003.

17. Appleby P, Thorogood M, Mann J, Key T. The Oxford Vegetarian Study: an overview. Am J Clin Nutr. 1999;70(3):525s-531s.

18. Song M, Fung TT, Hu FB, et al. Association of animal and plant protein intake with all-cause and cause-specific mortality. JAMA Intern Med. Published online August 1, 2016.