The Skinny on Protein – Should You Supplement?

Dr. Matthew NagraArticles, Plant-based Diet, Protein, Protein Powder, Protein Supplements, Vegan Protein

Image of protein powder in blender with blueberries and banana

Protein is a hot topic in the world of nutrition, with some claiming that our diets should be centred around protein, while others suggest that low or moderate protein diets are ideal for longevity. In fact, some ascribe the longevity of certain populations, such as the Okinawans, to their traditionally low protein intake.1, 2 This has unsurprisingly raised concerns regarding high protein intakes, and especially the use of protein supplements, which have become very popular amongst not only athletes, but much of the general population.

In addition, there appears to be a shift towards more plant-based protein sources amongst the general population. In fact, the market for plant-based proteins is expected to increase by 14% each year through to 2024, according to the Government of Canada.3 The demand for plant protein is increasing as more consumers prioritize their health, as well as wanting to choose more environmentally conscious alternatives, which can come in the form of legumes, including soy protein products, as well as vegan protein powders.

With all that said, is protein really the key to long-term health and if so, are protein supplements a safe addition to our diets? Let’s get into it.

How does protein impact long-term health?

Before diving into protein supplements (e.g., whey protein powder, vegan protein powder, etc.), let’s discuss the research on overall protein intake and long-term health. As mentioned previously, there are populations who’ve achieved excellent health while consuming relatively low protein diets – while still meeting the minimum recommended protein intake on average – but that doesn’t tell us if the low protein nature of their diet is responsible for their great health. 1, 2 It could be that their largely plant-based diet, physical activity, and other lifestyle factors are more responsible. To determine the impact of protein, we must look at the health of those consuming more or less protein within a given population while also adjusting for confounding variables.

This means comparing people with similar characteristics (ie. comparing non-smokers to non-smokers, physically active individuals to physically active individuals, etc.), which helps isolate the impact of protein. When we do this, higher total protein intake may actually be associated with a lower risk of mortality, meaning a lower risk of dying during a given period of time! 4,5 However, this appears to be specific to plant protein sources, not animal protein.

In fact, replacing even modest amounts (3% of calories) of animal protein sources with plant protein can lead to significant health benefits, which is likely due to the respective packages that animal and plant protein typically come in. 5  For example, animal protein often comes packaged with saturated fat, cholesterol, heme iron, and other compounds that may have a negative impact on our health, while plant protein typically comes packaged with fibre, phytochemicals, and other beneficial compounds. Some studies also try to equalize some of these compounds (ie. comparing individuals who consume similar amounts of saturated fat and fibre), but even then, plant protein sources tend to come out on top.

How much protein do you need?

Given that higher plant protein intake may be beneficial, you may be wondering just how much protein is ideal. The recommended dietary allowance for protein intake amongst healthy adults is 0.8 grams per kilogram (g/kg) of bodyweight, but higher intakes are likely beneficial over the long-term, and especially amongst elderly populations in which improvements in bone mineral density and lean mass have been seen with intakes up to 1.2g/kg or more (82g or more for someone who weighs 150lbs or 68kg).6,7,8,9,10 For these reasons and more, it has been argued that 0.8g/kg is suboptimal, and most individuals could benefit from increasing intake. Furthermore, strength athletes may benefit from intakes as high as 1.6g/kg to help maximize muscle and strength gains.11

A protein supplement can be a convenient tool to help meet these levels of intake while consuming a plant-based diet, but are they necessary? And perhaps more importantly, are they safe?

Plant-based protein: is it enough?

With regard to necessity, it is absolutely possible for most people to meet the aforementioned protein intake targets on a plant-based diet without supplements. The key is to include protein-rich plant foods, such as tofu, lentils, and seitan, as centrepieces of each meal. Of course, all plant foods contain some protein, including some amount of every essential amino acid, so it can add up from lower protein foods as well, but it would be difficult to reach intakes of 1.2g/kg or more without the help of some higher protein foods.

To help give some perspective on just how much protein some of these plant foods can have, seitan and textured vegetable protein (a high-protein and nutrient rich, soy-based flour) can have a similar protein content per calorie to even extra lean meat, while having a higher protein content than standard 80% lean beef. On the other hand, tofu has a similar protein content to standard beef, although lentils and other legumes typically have somewhat less, with chickpeas falling well below. Tofu also edges out eggs for protein and overall nutritional content.

Lastly, soy and pea milks are very comparable to skim milk while having a higher protein content than both 2% and full fat milk. As you can see, if one holds the common view that animal products make it easier to hit the ideal protein intake targets, there is absolutely no reason to believe that can’t be done with plant-based foods if one simply chooses those high protein options.


Protein Content of Protein-Rich Animal-Based and Plant-Based Foods

Food Protein Calories (kcal) Protein per 100kcal
80% Lean Beef


25.8g 270 9.6g
95% Lean Beef


26.3g 174 15.1g
Whole Egg

(2 large eggs)

12.4g 143 8.7g

(½ cup)

9.0g 115 7.8g

(½ cup)

7.3g 135 5.4g
Firm Tofu


8.2g 82 10.0g


12.0g 80 15.0g

(100g generic recipe) 12

17.9g 107 16.7g

(variable depending on recipe)

2% Milk

(1 cup)

8.2g 122 6.7g
Skim Milk

(1 cup)

8.4g 84 10.0g
Soy Milk

(1 cup)

8.0g 90 8.9g
Pea Milk

(1 cup)

8.0g 80 10.0g


In addition to adding protein to one’s diet, these protein-rich plant foods can also bring along calcium, iron, fibre, phytochemicals, and other beneficial components. Protein supplements, on the other hand, are typically concentrated protein with only modest amounts of micronutrients and phytochemicals. That’s not to say that protein powders aren’t beneficial; however, I would not suggest skipping on the beans and tofu altogether in favour of protein powder. Rather, protein powder can function as a supplement to one’s overall healthy diet to help consistently reach ideal levels of protein intake. So, if you find it difficult to consume ideal amounts of protein on a plant-based diet, a vegan protein powder can be a great way to supplement your overall macronutrient intake. With that, let’s move on to some of the most common beliefs about the harms of high protein intakes, and especially protein powders.

Are you consuming too much protein?

There is a pervasive belief that a high protein intake can damage our kidneys. While high protein diets are often advised against for those with chronic kidney disease (CKD), increasing protein intake, including via supplements, has not been shown to decrease kidney function in individuals without CKD, which has been extensively studied.13,14

Another concern is regarding insulin-like growth factor-1 (IGF-1). High intakes of certain amino acids, the building blocks of protein, that can be concentrated in animal foods or protein supplements may raise our IGF-1 levels, and high IGF-1 levels have been associated with an increase in mortality.15,16 However, dietary intake typically raises IGF-1 after meals, while having little impact on fasting levels. This is critical, because elevated non-fasting levels don’t appear to be associated with risk of mortality. Conversely, having low non-fasting levels may actually be.15

On the other hand, high fasting levels of IGF-1 may be problematic amongst those with cancer, but not healthy individuals. Does this mean that, if we’re healthy, we should be aiming to boost our IGF-1 levels? Not necessarily, but it does suggest that there isn’t reason to be concerned, and as discussed earlier, higher protein intake appears to be beneficial for body composition, bone health, and risk of mortality.4,5,6,7,8,9,

Is protein powder good for you?

A concern specific to protein supplements – the most popular form being protein powder – is the possible presence of heavy metals. Multiple analyses have evaluated the heavy metal content of protein powder and have sparked headlines about the proposed dangers of these products; however, the mere presence of a compound does not mean that the given product is harmful.17 In fact, heavy metals are present in virtually all foods, including fruits and vegetables, but higher consumption of those foods is consistently associated with better long-term health.18,19

What matters is the dose, and a comprehensive analysis of the doses typically present in protein powders found that they would be unlikely to alter blood levels of heavy metals by any significant degree nor impact disease risk. 17  However, I suggest purchasing products that have been third party tested for contaminants to ensure all compounds, if present, are within safety limits and the supplements contain what they say they do. Of further concern, some sports supplements can even contain banned performance enhancing substances. This is especially problematic for athletes competing in drug-tested sports.20

Amongst the best third party verifications for supplement safety, NSF Certified for Sport is the only one recognized by the United States Anti-Doping Agency, and they have a database of supplements that have been verified at NSF Sport.21 In addition to being a safe option for most people, protein supplements can also improve cardiovascular and diabetes risk factors, including cholesterol levels, markers of insulin resistance, and weight.22,23,24

Animal-based vs. vegan protein powder

Animal protein is often deemed as superior to plant protein for physical performance. However, comparisons between various plant and animal-based protein powders consistently demonstrate similar results. Even in the context of a vegan diet where most of one’s protein intake is coming from food sources, vegans also have high quality protein supplement options such as pea protein.25,26,27,28,29

It may be ideal to choose a vegan protein powder/ supplement that provides 2 to 3 grams of leucine, one of the branched chain amino acids, which has been shown to support optimal muscle protein synthesis, a marker of muscle growth.30 In addition to pea protein, soy, corn, and potato-based proteins typically have a high leucine content, making them great plant-based alternatives to whey.31 In fact, potato protein has recently been gaining attention due to its impressive amino acid profile.

What’s next?

In conclusion, ideal protein intakes are likely higher than the typically recommended intakes; however, supplements such as vegan protein powder is by no means necessary on a healthy plant-based diet. It’s possible for most people to meet these targets with the regular consumption of protein-rich plant foods. Foods such as lentils, tofu, and seitan are great protein-rich options. That being said, high quality vegan protein powder can be a safe and convenient addition to one’s diet. It can help increase overall protein intake, especially for elderly individuals and athletes, who may otherwise struggle to consume enough.

To achieve a healthy, balanced, plant-based diet that’s rich in protein (and other important nutrients), I’m here to help. You can book a consultation with me, Dr. Matthew Nagra, to learn more about how this plant-based lifestyle can improve your health.


Disclaimer: this paper has been published strictly for educational purposes and should not be taken as medical advice.