The 21 day Easy Vegan Challenge in New Zealand
First – let me get my bias out of the way: I eat a plant-rich omnivorous diet. I have eaten exclusively plant only in the past, however, I found for me it was not optimal. I use this knowledge as a nutritionist to assist my plant-only clients optimise their diet. It is with this knowledge I have concerns over the recommendations in the 21-day vegan challenge.
The Vegan Society of NZ is widely advertising their 21-day challenge. It is free to try, and on their website, they have a 7-day meal plan with recipes, as well as tips, and FAQ. It is advertised that you should try it ‘for your health’. 
I decided to check out their recipes and daily plans to see if, in fact, you would be healthier eating this way. I highlight some of my concerns about this particular vegan diet, particularly around protein intake.
I used a standard 2000 calorie per day template with the RDA of protein set at 0.8g per kg a day. This is the amount the World Health Organisation states (0.83 g per kg) is necessary for health.
The first point of concern is in the FAQ, with respect to their view on protein:
Is there really more protein in 100 calories of broccoli than steak?
Not according to cronometer:
Steak has 18.8 grams of protein in 100 calories which is just 63 grams, however, there is only 8.5g in 100 calories of broccoli, and you would have to consume 3.3 cups to get that.
In the same section on protein the Vegan Society also makes this statement:
“Studies to determine how much protein humans should eat were based on rat studies” Really? That is a bold statement – and there is no reference for it. They say the amount of 1g per kg a day is based on rat studies and that “Humans … do better on half that amount” which means their view is that humans only need 0.5g per kg a day, and this is better for people. Again no reference is given for this statement.
Here is a reference to the rat studies:
https://www.fao.org/ag/humannutrition/35978-02317b979a686a57aa4593304ffc17f06.pdf
Human requirements are not worked out solely on rat studies, however.
What do health authorities, and the research actually say about protein requirements?
According to the World Health Organisation (WHO) in their 265-page report Protein and amino acid requirements in human nutrition, the minimum needed for health is 0.66g per kg a day for an average person, however, they also state that that is not enough to cover all peoples needs and 0.83g/kg/day is required to meet the needs of 97.5 % of people. This amount is based on many human studies.
However, in the most recent studies on human protein requirements, the amounts needed have been re-evaluated upwards for optimal protein intake, according to this thorough overview by Examine.com. Their research shows the optimal minimum for a sedentary human is 1.2 grams per kg a day, this is the amount needed to maintain muscle mass. For others who are active more is needed.
The Vegan Society are worryingly out of touch with research on optimal protein amounts for humans.
How much protein does the vegan plan have per day?
I put days 1, 2, and 3 of the 7-day plan into cronometer to see how they look in terms of nutrients. I based goals on a 2000 calorie diet – the amount of food needed to maintain weight for a 65 – 70 kg adult doing light exercise.
Here is what cronometer showed for days 1 and 2:
Firstly – the whole day added up to around 1500 calories, so most average people will lose weight. However, the concern I have is the tiny amount of protein included in each day, and the fact that essential amino acid requirements have not been met for day 1,2,or 3.
You might also notice that day 2 is the only one to contain a little B12, usually completely missing in a vegan diet. That was supplied by a serving of Marmite.
Looking through the plan – day 7 has the most protein included in the day, so I analysed it and found it reached adequate levels of amino acids. It also had better overall nutrients reaching 87%, with B12 the primary vitamin deficient. To the Vegan Society’s credit – they emphasise the importance of supplementing B12.
Why is day 7 so much higher in protein? The reason is the food choices. One meal contained 150 grams of tofu, another 1 cup of cooked lentils. Both these choices are higher in protein. Tofu also supplies calcium another nutrient low in vegan diets.
Why is protein so important?
Let’s take a look at the three macronutrients – protein, carbohydrate, and fat. Of these three, protein is the only one that cannot be manufactured or stored in anything but a small amount in our body. Carbohydrates are primarily used as fuel, as are fats. Both are stored when not used. Both can be made in our bodies or pulled from storage.
Protein on the other hand is made into everything that our body is built from, and insufficient protein will affect your ability to repair and rebuild every single tissue. This graphic shows just some things protein or amino acids are used for:
My own experience on a typical vegetarian diet that was low in protein was poor recovery after exercise, hunger, and slow gains whenever I exercised. My recovery after exercise, my energy, and my mental focus all improved markedly when I increased my protein to the current recommended levels, with a serving at every meal.
I have many concerns about this particular vegan diet plan, it is deficient in many nutrients, calories, amino acids, and protein in general. I do not recommend you try this challenge.
If you do choose to eat an animal protein-free diet, it is critical you do so with the knowledge of potential deficiencies that will need to be rectified with supplements or certain food choices.
More about that in another post.
