As a nutritionist, I was excited to watch the new Netflix documentary The Game Changers, which sets out to prove that a plant-based diet is better for your health. But as the film progressed, I became more and more disappointed with the lack of responsible nutritional information and the disingenuous way in which experiments and studies were presented.

Anyone who comes to a consultation with me will tell you that I am obsessed with getting more variety into our diets, and yes, I will almost always ask people to cut down on their meat consumption and to add in more vegetarian protein options such as beans, pulses, nuts and seeds. These are great for adding fibre, nutrients and supporting the microbiome. I also often ask people to eliminate dairy and wheat to see if it helps with any number of symptoms. But to encourage people to go fully plant-based (it sounds more appealing than vegan, doesn’t it?) without reference to possible deficiencies is irresponsible at best, and dangerous at worst.

As far as the environmental and animal welfare arguments go, I get it. And I’m with you. But I also know that going vegan from a nutritional point of view demands hard work and effort to get it right. Here are a few of the more glaring issues with the documentary and my problems with them.


First of all, the documentary features mainly elite athletes. As others have already mentioned, I can guarantee you that these athletes will have a team of nutritionists, physios and other experts behind them who will be monitoring their nutrient levels and making sure they are supplementing any deficiencies. Because the truth is, it is virtually impossible to eat a vegan diet without having to lean on supplementation. I had a professional vegan bodybuilding client a few years ago who asked me to review his diet. His wife, like the wife/chef for the American Footballers in the documentary, had given up her job to assist him full-time. Her day was taken up by preparing his meals but – of equal importance! – making sure he followed his lengthy supplement regimen, too.


To say that plant protein has the same nutritional value as animal protein in terms of complete amino acid profile is false. You can make sure you obtain all the amino acids by combining different plant sources, but if you tend to eat the same things all the time (which a lot of people do) that becomes hard. Vegans need to make sure that they vary their protein sources and include a good range of beans, pulses, nuts, seeds and some soya.

Which leads me to the soya issue. The documentary states that phytoestrogens (found in plants) can raise testosterone levels. I have been unable to find any study either on their website or anywhere else that backs this up. What we do know is that phytoestrogens (of which soy is one) can bind onto oestrogen receptor sites in the body and mimic what oestrogen does. It’s why they can be helpful for women going through menopause. When it comes to soy and men, however, you need to take into account genetics and the microbiome. Asian men, who have been eating soy for generations, have both the genetics and bacteria in their gut that helps them absorb and utilise soy in a positive manner. However, males from other genetic backgrounds who consume a lot of soy may find it has negative effects on testosterone and fertility. The documentary never explains this.


The use of scientific studies in the film is abysmal. They often take extremely small studies that have several other mitigating factors and extrapolate them to justify their claims. For example, the blood flow experiment. The study this is mostly based on is a 2018 meta-analysis of three studies that covered just 60 people in total. One of these studies was actually looking at the effect of bonito broth on blood flow rates (bonito broth is made from dried tuna flakes). The bonito broth improved blood flow. But the producers ignore that, and instead use the other two studies (30 people in total) to say that a vegetable diet will improve blood flow and viscosity.

I spend a lot of time telling people to eat more plants and vegetables to improve their heart health and cholesterol levels. But to ask people to cut out all animal products completely can have many pernicious effects, mostly down to micronutrient deficiencies. One of the few segments that did not involve an elite athlete was the study with the firemen, who were asked to go vegan for a week while the effects on their blood pressure and cholesterol were measured. What I found problematic about this experiment (apart from the leader’s KALE T-shirt) was that animal products probably weren’t the only things that the firemen gave up that week. I would imagine their diets were completely transformed. As well as giving up animal products, they would have given up sugar, alcohol and possibly caffeine as well. The programme did not tell us what their diets were like before, but there is no way they can claim that it was cutting out the meat and dairy alone that made the difference. In most recent studies on cholesterol and cardiac health, it is cutting out the processed foods and sugary carbohydrates that has a far greater effect on health than removing the animal fats.


The most irresponsible part of this documentary, and usually the biggest gap in knowledge for vegans, is the lack of information on possible micro-nutrient deficiencies. Yes, they will tell you about vitamin B12, iron and possibly the essential fatty acids, but they rarely tell you about vitamin A, B5, zinc, choline and many others, which can affect bone health, energy levels and much more.

There are two main reasons behind these possible deficiencies. Firstly, several vitamins, minerals and nutrients have different chemical forms depending on whether they are originally produced by animals or plants. For example, iron found in animal products is called heme iron and has a slightly different chemical structure to the iron found in plants, called non-heme iron. As animals ourselves, we find the plant forms of nutrients much harder to absorb and metabolise. We can absorb heme iron twice as easily as non-heme iron; it is also easy to decrease the absorption of non-heme iron when you drink coffee or tea. This is the reason that iron deficiency is currently the most common diet-related health issue in the world.

Secondly, to convert the plant form of nutrients to the animal forms that we can use, we need certain genes to switch on and to produce enzymes. But this can get complicated. Take Vitamin A, for example. Our bodies can only use retinol, which is the animal form. Plants, however, contain carotene, which is chemically different. When you eat a carrot, full of beta-carotene, you need to convert that carotene to retinol before the body can derive any use or health benefit. That conversion is already quite hard, but what most people don’t know is that roughly 40% of the population carry two genetic variations that slow down that conversion even further by up to 60%.

Between them, these two factors influence your absorption and ability to metabolise many different nutrients. You may have the perfect genetic set-up that allows you to easily convert every plant nutrient into a form that you can use. But the chances are, you don’t. And the only way you are going to find out is when your health suffers.

So here’s my conclusion. Yes, in general we need to cut down on how much animal protein we eat, and many people will benefit from exploring their sensitivities to dairy. Anyone suffering from cardiovascular or inflammatory issues might especially benefit from a switch to a plant-heavy diet. I will happily provide information and support anyone who wants to try going vegan for January, too. But please don’t go vegan altogether without consulting a qualified nutritionist, and being fully conscious of the possible consequences and nutritional impacts.