To eat meat, or not to eat meat – that is the question on everyone’s lips right now. There’s no denying the sheer satisfaction of tucking into a juicy steak or a cheeky burger. However, there’s an increasingly overwhelming amount of evidence that suggests that eating less meat not only helps you live a longer and healthier life, but is also better for the environment as well.

If you’re concerned about your health or your impact on the environment, you might be starting to reconsider your daily meat intake. Luckily, there is a middle ground between scarfing down a Full English everyday and cutting out meat completely. There’s plenty of evidence to suggest that a flexitarian diet will give you the best of both worlds.

According to the Carbon Brief, “the food system is a major contributor to climate change and, without significant shifts in global diets, it is unlikely the world will achieve its targets under the Paris Agreement”.

Research published in the science journal Nature reports that, compared to baseline projections for 2050, moving to a more plant-based flexitarian diet could reduce greenhouse gas emissions by as much as 52 per cent.

Research published in the science journal Nature reports that, compared to baseline projections for 2050, moving to a more plant-based flexitarian diet could reduce greenhouse gas emissions by as much as 52%.

Meanwhile, Lancet Medical Journal published a study that calls for dramatic changes to food production and the human diet in order to avoid “catastrophic damage to the planet”. Additional research from Johns Hopkins University also concluded that if the world adopted a flexitarian dietary pattern (defined as including completely plant-based meals two out of three meals each day) it could result in a potential 41% reduction in food-related emissions.

Cows produce milk for the same reason that humans do—to nourish their young—but calves on dairy farms are taken away from their mothers when they are just 1 day

Cows produce milk for the same reason that humans do—to nourish their young—but calves on dairy farms are taken away from their mothers when they are just one day old.

What about our personal health

Caring for our environment is important – but so is caring for our own health as well. According to the 2017 research paper ‘A review of the evidence-based literature’ by Frontiers in Nutrition, there was emerging evidence that eating less meat could result in healthier body weights, improved markers of metabolic health, better blood pressure and a reduce risk of type 2 diabetes. This review also suggested that an “SVD” (semi-vegetarian diet) might also have a role to play in the treatment of inflammatory bowel diseases, such as Crohn’s disease.

Meanwhile, the EPIC Study (European Prospective Investigation into Cancer and Nutrition) collected data on fibre intake and colorectal cancer in 519,000 people across Europe. They found that 20% of people who consumed the most fibre in their diet (about thirty four grams per day) had a 42% lower risk of colorectal cancer than the 20% who consumed the least fibre in their diet (about thirteen grams per day).

One of the dietary factors that contribute to colorectal cancer is a low-fibre diet

One of the dietary risk factors that contributes to colorectal cancer is a low-fibre diet.

Fad diets

When it comes to diets, there are plenty to choose from – calorie counting, Weight Waters, Slimfast, Paleo, FODMAP, etc. The list is truly endless, so you might be thinking, “so, what makes a flexitarian diet different?”

Well, many of these diets aren’t solely about improving your health – they’re simply a fantastic way for companies to make money from consumers that haven’t been properly educated in nutrition. In fact, your health and well-being is secondary to some of these companies – if it’s even a consideration at all. Most diets eventually fail – and as a personal trainer and athlete, I don’t promote any diet unless I’ve researched the science, tried it, seen results and stuck with it.

However, I truly believe that the flexitarian diet is an easy and sensible way of eating. Not only does it enhance our own well-being, but it also has a positive effect on climate change and helps meet the targets set out in the Paris Agreement. However, in order to really understand the benefits of flexitarian eating, let’s take a brief look at our gut.

We are omnivores

Human beings are a relatively recent addition to this planet. The first species of human emerged in Africa around two million years ago, with the first Homo Sapien appearing around 300,000 years ago (although this is still debated by scientists). Our ancient Homo Sapien ancestors eventually migrated out of Africa, gradually replacing other human species and settling in fertile grounds.

Picking fruit at an optimal harvest date

Picking fruit at an optimal harvest date.

Humans are omnivorous and are capable of eating a wide variety of plant and animal material. We can survive without food for up to eight weeks and without water for three to four days. Our teeth are better suited for fruit and vegetables than ripping flesh. Interestingly, our guts are too long to be total carnivores. However, our guts also aren’t long enough to be herbivores.

Instead, the design of a human is decidedly omnivorous. Our bodies can handle meat and plant matter pretty well and a human gut is very similar to our closest relatives, monkeys and apes, who consume nuts, fruits, leaves, insects and an occasional flesh meal.

Vegan, Vegetarians and Meat

Aside from being highly palatable, meat is also packed with protein and vital nutrients. Your body needs protein to be able to maintain and build itself. Within protein, there are nine amino acids that are essential – this means that our body cannot make them itself and they need to be ingested. Animal meat is a complete source of the nine essential amino acids, which is why including a moderate amount of meat in a diet can help keep you healthy.

Foods such as nuts, seeds, legumes, grains and vegetables are considered incomplete proteins, as they’re missing one or more of the essential amino acids. Vegetarians can pair their foods together to complete all nine amino acids, but vegans must take a vitamin B12 supplement.

Fish and red meat are excellent sources of vitamin B12

Fish and red meat are excellent sources of vitamin B12.

Very low levels of vitamin B12 can cause anaemia and nervous system damage. B12 can be found in soil and plants to some extent and some specific foods, including spirulina, nori, tempeh, and barley grass, are advertised as suitable non-animal sources of B12. However, such claims have not stood the test of time.


We are the only mammal that drinks another species milk. Drinking cows milk was introduced some 6,000 – 8,000 years ago from dairy farmers in Kenya and Sudan. Without getting into the questionable ethics of dairy farming, humans are not designed to drink another animal’s milk or to consume milk in adulthood.

It is completely unnatural. Cow's milk is intended only for baby cows

Drinking cow milk is completely unnatural for humans. Cow’s milk is intended only for baby cows.

Milk contains a sugar called lactose. When we are babies, our bodies produce an enzyme called lactase. This allows us to digest our mother’s milk. When we are about 5 years old, our bodies stop producing lactase. Without lactase, we cannot properly digest milk. The results can include stomach cramps, diarrhoea and a host of side effects.

Some people in parts of the world (mainly Europe and Africa) have mutated sections of DNA from generations of milk drinkers that allows them to keep their lactase enzyme partly active into adulthood. However, this does not mean that it is ok to drink or eat dairy. Dairy contains high levels of saturated fats – and eating a diet high in saturated fat is associated with raised levels of LDL (bad) cholesterol. This is then subsequently linked to an increased risk of heart and circulatory disease.

Eating saturated fat leads to the accumulation of more visceral fat

Eating saturated fat can lead to the accumulation of more visceral fat.

And the case for Casein

When it comes to consuming dairy, we hear a lot about lactose. However, casein (which gives the milk its white color) makes up 80% of milk and can also be problematic. Casein is very difficult to digest and puts a strain on the digestive system. It can also cause respiratory issues, as its thick and coarse nature forms mucus that clogs up the respiratory system. It’s also very similar in structure to gluten and can cause intolerances with people who are already intolerant to gluten.

Interestingly, research has even linked the high fat content and hormones in milk, cheese and other dairy products to breast cancer. In addition, Casomophins are components of casein. When the body digests casein, Casomophins attach to opiate receptors in the brain, which can make us addicted to dairy products.

If you’re concerned about calcium, you might be interested to learn that eliminating dairy from your diet can actually increases your bone density. Unlike plant protein, animal protein will actually increase the acid load in the body. An increased acid load means that our blood and tissues are more acidic. The body tries to neutralise the acidity of the blood by using calcium, which is highly effective. However, this calcium must come from somewhere. If there isn’t enough calcium from other sources, it ends up being pulled from the bones, which weakens the bones and puts them at greater risk of fracture. 

Alternative sources of calcium can be found in broccoli, cabbage, beans, peas, lentils, almonds, Brazil nuts, seeds and kale. With the downsides of dairy in mind, there are two types of flexitarian diet that you can choose to follow: vegetarian and vegan. I choose the vegan option and have eliminated dairy from my flexitarian diet.

Processed Meats

Processed meats contain certain chemicals that are carcinogenic. The World Health Organization has classified processed meats such as ham, bacon, salami and sausages as a Group 1 carcinogen (known to cause cancer), which means that eating processed meat will definitely increase your risk of bowel and stomach cancer. Meanwhile, red meat, such as beef, lamb and pork, has been classified as a Group 2A carcinogen, which means it probably causes cancer.

Processed meat has been classified as a 'definite' cause of cancer

Processed meat has been classified as a ‘definite’ cause of cancer.

Current research shows that there are certain chemicals in red and processed meats – both added and naturally occurring – that cause these foods to be carcinogenic. For example, when a chemical in red meat called haem is broken down in the gut, N-nitroso chemicals are formed. These have been found to damage the cells that line the bowel, which can lead to bowel cancer. These same chemicals also form when processed meat is digested. In addition, the nitrite and nitrate preservatives used to preserve processed meat also produce these N-nitroso chemicals – and can subsequently lead to bowel cancer.

Ensuring that the meat you consume comes from organic or biodynamic small-scale farms is advantageous to both your health and the planet. The meat from these farms provides greater nutritional benefits, more good omega-3 fatty acids, less cholesterol, and more antioxidants – plus a lower risk of exposure to antibiotics, growth hormones and pesticides.

I’d also recommend purchasing line-caught fish from small-scale fisheries that don’t have the bycatch or stock-depletion problems that are associated with trawling with massive nets. Line-caught fish also tends to be of better quality than trawled or netted fish, as it suffers less stress and damage during capture. However, I would recommend avoiding farm-raised fish, as it may have as much as 20% less protein compared to wild fish. Additionally, PCBs (cancer-causing chemicals) may exist in farm-raised salmon at a concentration 16 times higher than wild salmon.

Eat Meat Sparingly

Okay, so you might logically understand the benefits of eating less meat. However, how can you logistically create a flexitiarian diet that’s sustainable for you?

To keep things as simple as possible, try imagining a world before mobile phones, cars, TVs and (most importantly) supermarkets. Imagine hunting for your dinner by covering vast distances, looking for food – no matter whether it’s plant or flesh. Our ancient ancestors would have struggled to find, catch and kill animals on a daily basis, so eating plants meant that we would have had the energy to sustain ourselves between meat-based meals.

If you’re still dubious, it’s worth noting that this idea is supported by evidence that eating meat sparingly during the week can have massive health benefits.

Benefits of a non-dairy flexitarian diet

Following a flexitarian vegan diets offers many of the same advantages as a vegetarian diet, but it eliminates the need to consume diary. Going semi-vegan can help your body, your wallet and the planet in ways you might not imagine.

I enjoy eating this way – I feel satiated, energised, fit and healthy. It works for me and the evidence suggests that it’s a healthy way to eat. I will leave you with some of the benefits associated with eating a flexitarian (vegan) diet:

  1. Lower risk of heart disease
  2. Lower blood pressure
  3. Lower risk of colorectal cancer
  4. Lower risk of type 2 diabetes
  5. Lower greenhouse emissions and fossil fuels
  6. Animal welfare
  7. Reduce inflammation
  8. Improved body composition
  9. Sustainable long-term method of eating
  10. Improved gut health