Plant based protein: Not as easy as vegan infographics will have you believe.

Many times, you will hear vegans claim that it isn’t at all difficult to get enough protein eating only plant based protein sources, without resorting to supplements. They will list things like broccoli, beans and potatoes as important sources of protein. In today’s blog post I want to explore these claims and look at the commonly suggested sources of plant based protein to see if these claims hold.

When looking at protein, it is important to realize that, next to being an important building block for your lean body mass, protein, like fat, sugar and starch, is also a macro nutrient that counts towards your energy intake. Depending on your lean body mass and physical activity level, your body will need to burn a number of calories.

The more food you eat that is rich in fat and carbohydrates, the less room you will have, calorie wise, for getting the protein you need. Just like money, where you can spent every Euro only once, you can also spent a calorie only once in your macro-nutrient intake. The trick for getting enough protein lies in eating food with a high enough protein calories to total calories ratio.

The ideal ratio depends on a number of things:

• Your lean body mass
• Your activity level
• How static you want your body composition to be

We will look at this with an example. Let’s say you are a 75 kg male with a body fat percentage of 33.3%. You are physically active, working at the gym to improve your body composition.

Let us first look at your protein intake. A good rule of thumb for adequate protein intake is to take ten calories for each kg of lean body mass. Given that we have a body fat percentage of 33.3%, we need to subtract 33.3% from our body mass of 75 kg to find our LEAN body mass. In our case this would be 50 kg. At 10 calories per kg LBM, this means we should aim to get at least 500 of our daily calories from protein.

The second thing we need to look at is our daily energy expenditure. To find this, we look at using Catch McArdle. Given that we are working out at the gym all the time, but aren’t particularly active in our day job, using an activity factor of about 1.5 is appropriate.

Filling out our LBM and activity factor into the Catch-McArdle equation, we find our daily energy expenditure to be approximately 2175 kcal. This means that if we consume 100% of our daily expenditure, we would need to get at least 23% of our calories from protein.

But note this is at an energy equilibrium. So what if we wanted to loose some of our body fat. We would need to create an energy deficit. 10%, 25% maybe. At a 10% deficit we would need to increase the percentage of calories we get from protein to about 25.5%. At a 25% deficit, it would jump up to a whopping 30.5%.

Now we know what our minimum protein uptake should look like, let us look at the plant based protein sources that are often quoted by plant-based advocates. I will try to show the numbers in a way that should I hope show how many sources of plant based protein simply can’t add up.

So let us look at our sources of plant based protein. What we shall be looking at is an answer to the following question:

If our guy was to get ALL of his 500 protein sourced calories from a given plant based protein source, what percentage of his 2175 kcal daily energy expenditure would that plant based protein source entail?

Here is an infographic that has popped up in my twitter feed a number of times.

Let us answer our question for the plant-based protein sources in this vegan infographic.

• Avocado 460%
• Almonds 160%
• Oatmeal 160%
• Quinoa 155%
• Pumpkin seeds 135%
• Peanut butter 135%
• Hummus 120%
• Black beans 95%
• Lentils 75%
• Broccoli 70%
• Tempeh 60%
• Tofu 55%

As you can see, seven out of twelve of our plant based protein sources have pretty bad ratios and thus can be dismissed as prime sources of plant based protein. But some of the remaining plant based protein sources have issues of their own. To get our 500 calories from protein using broccoli only would require our guy to consume a whopping 5 kg of broccoli a day. Tofu: 1.6 kg. Lentils: 1.4 kg.

We are left with only tempeh and black beans as viable protein sources at respectively 600 and 650 grams a day. And with a bit of fine tuning, it might be possible to get a reasonably complete amino acid profile using these two as main staples combined with others such as hemp seed. One thing stands out though. The idea that protein is nothing to worry about on a vegan diet is false. Protein should be a main concern in any diet, especially a diet that restricts certain protein rich foods or favors either high fat or high carbohydrate foods without much notion to protein. So if by choice, you are on a plant-based diet or any other such restrictive diet including the other side of the far/carb spectrum, a keto diet, have a real good look at your protein intake. Chances are your protein is way below the low end of the optimum protein intake zone, somewhere close to 10 protein calories per day for each kg of lean body mass.