Eating for the Planet


Are you confused by all the contradictory dietary advice out there?

Should you go low fat or low carb? Vegan or paleo? Ketogenic? Mediterranean? Pescatarian?

The truth is, it’s extremely difficult to prove that there’s one universal diet that’s superior to all others, certainly in terms of its effects on health and peak performance.

One thing is clear, we shouldn’t be eating the prevailing low quality Western diet, which is high in refined sugar, processed and red meat and saturated fat. This pattern of eating has resulted in 2 billion people being overweight or obese, and has fuelled the increasing prevalence of non-communicable diseases such as type 2 diabetes, cardiovascular disease and cancer (1,2).

In reality, many people will derive significant health benefits if they stick to a few simple, evidence based food principles.

However, if we really want to answer the question of “what should we eat?” then we must also consider planetary health, as this is inextricably linked to our own health and survival.

And when we take the planet into consideration, the answer is very clear: we should eat a plant-based diet.

This is the conclusion of a number large-scale, mainstream scientific studies (3,4,5), including the recently published literature review by the EAT-Lancet Commission (1).

So why is a plant-based diet best for the planet?

To answer this we need to look at our current system of food production, which we now understand to be the single largest contributor to environmental degradation.

Food systems account for up to 30% of global greenhouse gas emissions(1,3,5). However, climate change is only part of the story. Food systems drive a range of serious environmental issues that now threaten human health and survival, including biodiversity loss, eutrophication and depletion of fresh water supplies.

Food production is the largest cause of global land-use change, with 40% of terrestrial land used for crops and grazing. This has resulted in massive biodiversity loss, to the extent that we are witnessing the Earth’s 6th Mass Extinction Event. Species are being lost 100-1000 times faster than the natural background rate. 80% of extinction threats to birds and mammals are due to agriculture (1).

The impact of humans and our agriculture is now so great that it has drastically altered the make-up of global biomass (the total weight of living matter in a given area).

Humans comprise just 0.01% of Earth’s total biomass, but our impact is disproportionately large; 96% of all mammals are either humans (36%) or our livestock (60%) – mainly cattle and pigs. Only 4% of mammals are wild. 70% of all birds on the planet are farmed poultry. Only 30% are wild (6).

Food production is responsible for 78% of eutrophication (1,5). This refers to the excessive application of nitrogen and phosphorus fertilisers, which are washed off into streams and rivers, causing algal blooms and hypoxic conditions in freshwater and marine ecosystems, which results in widespread coastal “dead zones,” devoid of aquatic life.

In areas where fish still exist, 60% of the world’s fish stocks are now fully fished, and 30% are overfished. Catches by global marine fisheries have been declining since 1996 (1).

The overall negative impacts of our food systems are very clear, but we still need to eat. So what we really want to know is: which food products are ecologically sustainable, and which are harmful.

To answer this, Joseph Poore and Thomas Nemecek performed the largest study to date of the impacts of agriculture on the environment, and their results were published in Science in 2018 (5).

They undertook a global analysis of data from 38,700 farms in 119 countries, looking at 40 food products, in terms of their effects on five key environmental indicators: greenhouse gas emissions, land use, acidification, eutrophication and freshwater withdrawals.

They found that even the most sustainable animal products exceed the average impacts of plant protein. As a result, if we were to switch to a plant based diet, it would reduce land use by 76%, greenhouse gas emissions by 49%, acidification by 50%, eutrophication by 49% and freshwater use by 19%.

In countries such as the UK, Australia and the USA, where meat consumption is 3 times the global average, the effects would be even greater.

The authors concluded that moving from a meat-based to plant-based diet has “transformative potential” and that avoiding meat and dairy is the single biggest way we can reduce our ecological impact.

But what exactly should we eat? What does a diet that is both healthy and ecologically sustainable look like?

This key question was finally addressed by EAT-Lancet Commission (a joint project by the Norway based NGO EAT and the Lancet Medical Journal), which undertook an extensive literature review and published its results earlier this year (1).

They came up with a universal healthy reference diet, or Planetary Diet, which is predominantly plant-based, provides 2500 kcal per day, and consists largely of vegetables, fruits, whole grains, legumes, nuts and unsaturated oils. It specifies a low to moderate amount of seafood and poultry, and no or low amounts of red meat, processed meat, added sugar, refined grains and starchy vegetables.

In practice, the Planetary Diet is similar to a Mediterranean or Okinawan Diet, which for many Europeans represents quite a shift in the way they eat. It would involve a 77% reduction in red meat consumption (by allowing only 1 beef burger per week), 15 times more intake of nuts and seeds, 2 servings of fish per week, 1-2 eggs per week, and 1 glass of milk per day (or 250g of full fat milk products).

So, having read this, are you now going to adopt the Planetary Diet, or perhaps go completely vegan? Maybe not…

Behavioural change is notoriously difficult. Even if there was widespread acceptance of the problems associated with our current level of consumption of animal products, awareness of an issue is no guarantee that people will adopt a more sensible path, as most health practitioners will attest.

This is certainly true for plant-based dietary change, probably because for many societies, eating animal products is the traditional, dominant eating pattern. A rejection of meat represents a rejection of social norms. It’s also important to appreciate that food confers much more than nutritional needs. It’s a source of pleasure, personal identity and economic status. In many developing countries eating meat is aspirational and symbolic of wealth. For some people, meat is associated with masculinity.

This is borne out by studies of public perceptions surrounding food impacts and dietary change, which suggest that there can be scepticism of the scientific evidence, resistance to the concept of reducing meat intake, and that non-food related behaviour change is deemed more acceptable (7).

However, eventually a threshold is usually reached, beyond which our resistance to change is overpowered by the realisation of the gravity of a situation, accompanied by a sense of urgency; such as when a patient receives a diagnosis of a life-threatening condition and finally feels compelled to make radical lifestyle changes. Perhaps as a society we are approaching that point with environmental degradation and non-communicable diseases.

Recently it feels as if the tide may be turning, with the global support for Greta Thunberg and the climate strikes, the Extinction Rebellion protests, and the increasing cultural acceptability of plant-based eating.

Make no mistake, we have very little time left to limit climate change to a survivable level and prevent further irreversible biodiversity loss. We urgently need to make transformative changes if we hope to do this, and there is no doubt that a global shift towards healthy, plant-based diets represents a very powerful tool.

If you still need some convincing, or are finding it difficult to make the leap to a more plant-based lifestyle, here are a few tips and suggestions:

First, watch the movie “Cowspiracy” (you can find it on Netflix).

Start experimenting with plant-based eating. There are now tonnes of resources out there (even confirmed omnivorous chefs such as Hugh Fearnley-Whittingstall and Jamie Oliver are jumping on the bandwagon). The key is to find a tribe that suits you.

Personal favourites:

  • River Cottage Veg Everyday and Much More Veg
  • The Happy Pear
  • Thug Kitchen (Eat like you give a f*ck)

Get inspired and check out some incredible plant based athletes, for example:

  • Rich Roll
    • Ultra-endurance athlete
    • Author of Finding Ultra
    • Host of The Rich Roll Podcast
  • Scott Jurek
    • Elite US ultrarunner
    • Author of Eat and Run


  1. Willett W, Rockström J, Loken B, Springmann M, Lang T, Vermeulen S, et al. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems. The Lancet. 2019 2019/02/02/;393(10170):447-92.
  2. Afshin A, Sur PJ, Fay KA, Cornaby L, Ferrara G, Salama JS, et al. Health effects of dietary risks in 195 countries, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet. 2019;393(10184):1958-72.
  3. Aleksandrowicz L, Green R, Joy EJM, Smith P, Haines A. The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review. PLOS ONE. 2016;11(11):e0165797.
  4. Clark M, Tilman D. Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice. Environmental Research Letters. 2017 2017/06/01;12(6):064016.
  5. Poore J, Nemecek T. Reducing food’s environmental impacts through producers and consumers. Science. 2018;360(6392):987.
  6. Bar-On YM, Phillips R, Milo R. The biomass distribution on Earth. Proceedings of the National Academy of Sciences. 2018;115(25):6506.
  7. Macdiarmid JI, Douglas F, Campbell J. Eating like there’s no tomorrow: Public awareness of the environmental impact of food and reluctance to eat less meat as part of a sustainable diet. Appetite. 2016 2016/01/01/;96:487-93.


Chocolate Mousse

A rich, nutty, chocolate mousse. There are other takes on the plant-based chocolate mousse but this one is a favourite, and uses silken tofu as the secret ingredient. Don’t let this put you off! (but check out this recipe for avocado chocolate mousse as well)


(Serves 4)


  • Silken tofu – 300g (drained)
  • Smooth nut butter – 100g
  • Maple Syrup – 1 tablespoon (substitution – honey)
  • Dark Chocolate –  100g (melted)
  • Chia seeds – 1 tablespoon (optional)
  • Fine sea salt – pinch

Berry Compote

  • Mixed frozen berries – 1 cup
  • Honey – 1 tablespoon (optional)


  • Place the tofu, nut butter, maple syrup, melted dark chocolate, chia seeds and salt in a food processor and blend until smooth
  • Spoon the mousse into individual bowls, cups or glasses (spatula also required)
  • For the compote, heat the frozen berries (+/- honey) gently in a  saucepan
  • Stir gently to prevent sticking
  • Allow to cool
  • Place a few spoonfuls of compote on top of the mousse
  • Leave in the fridge for a couple of hours before eating





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Nutty Chocolate Mousse

Random Veggie Pizza

A great way of using up excess veggies. You can make the tomato sauce (and even the dough) in bulk and freeze for future meals.


Pizza Dough

  • 250g Wholegrain Bread Flour
  • 250g Strong White Bread Flour
  • 1 teaspoon salt
  • 1 teaspoon raw sugar
  • 2 teaspoons dried yeast
  • 1 tablespoon olive oil
  • 350ml warm water

Tomato Sauce 

  • 2 x 400g (2 tins) chopped/ whole tomatoes
  • 1 red onion – finely chopped
  • 2 cloves garlic – roughly chopped or pressed
  • 2 tablespoons olive oil
  • 1 teaspoon raw sugar
  • Handful of basil leaves
  • Salt and  black pepper for seasoning

Pizza topping (suggested, but try making up your own)

  • Red onion – finely sliced
  • Mushrooms – finely sliced
  • Broccoli – chopped into small pieces
  • Red pepper – thinly sliced
  • Olives – chopped
  • Feta cheese – 125g

Pizza base:

  • Add the flour, yeast and sugar to a large bowl and mix together well
  • Then add the olive oil, salt and water, and mix into a rough dough
  • Flour your hands and place the dough onto a floured kitchen bench
  • Knead for about 5 minutes until smooth (it will be very sticky initially)
  • Place the dough into a clean bowl, and cover with a tea towel
  • Place the bowl in a warm place and allow the dough to rise for at least 1 hour
  • Once the dough has roughly doubled in size, poke it with your fingers until it collapses
  • Take your collapsed dough and cut it up into 4-5 pieces which will be used as your pizza bases

Tomato sauce:

  • Heat the olive oil in a saucepan, then add the onion and garlic and cook for 5 minutes over a low-medium heat
  • Add tomatoes, sugar, salt and black pepper
  • Simmer for 30 minutes until you have a thick sauce
  • Tear up the basil, add to the sauce and cook for another couple of minutes
  • The sauce can be used immediately, kept in the fridge for a couple of days, or stored frozen for up to 6 months

Making up the pizza:

  • Preheat your oven to 240ºC and put in a large baking tray/ pizza tray to heat up
  • Place one of your dough pieces onto a floured sheet of baking paper and roll it out very thinly with a rolling pin to create your pizza base
  • Spread a few tablespoons of your tomato sauce over the base, not too thinly
  • Now start adding your toppings – mushrooms, broccoli, red pepper, olives etc
  • If adding onion or leek, add them last to ensure they are cooked properly
  • Remove the baking tray from the oven and slide your pizza and baking sheet onto the hot baking tray, and return to the oven
  • Cook for 7 minutes, remove, crumble over the feta cheese and return to the oven for another 3 minutes
  • Remove/ slice/ serve




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Bircher Muesli


Breakfast of champions!

Prepare the night before.

Ingredients: (for 1 serving)

  • Oats – 2 cups
  • Sunflower seeds – 1-2 tablespoons
  • Raisins or sultanas – 1-2 tablespoons
  • Almonds – 1-2 tablespoons
  • Chia seeds – 1 tablespoon
  • Cinnamon – 1 teaspoon


  1. Mix the dry ingredients in a bowl or kilner jar and soak in water overnight (variation – soak in apple juice overnight instead)
  2. In the morning, add some grated apple and seasonal berries, and stir through a couple of tablespoons of natural yoghurt for a creamier texture
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Bircher Mueseli

Green Smoothie

Most of us could do with eating more vegetables, and blending them into a smoothie is a quick and easy way of improving our daily intake.

There are of course endless variations on the green smoothie; here’s one:

Basic ingredients:

  • 5 kale leaves
  • A handful of spinach leaves
  • 1/2 frozen banana
  • 1.5 cups rice milk or coconut water

Try adding:

  • 1 teaspoon hemp protein
  • 1 teaspoon flax seeds
  • 1 teaspoon chia seeds

Place in a blender and whizz for 30 seconds.

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Green Smoothie

Doctors as environmental advocates

By Tim Smith

As we destroy nature, we destroy ourselves. It’s a selfish thing to want to protect nature

– Yvon Chouinard (American climber, environmentalist and businessman)

Humans are not separate from nature, but part of it. As a society, we urgently need to relearn this concept, for the sake of our health.

It’s well established that our survival depends on intact ecosystems and biodiversity (the variety of life on earth). They provide us with essential life-support services such as food, clean air and water, healthy soil, medicines and disease regulation.

However, we don’t just need nature to survive, we also need it to thrive: there is now a growing evidence base to support what we intuitively already know; that our physical and mental health and wellbeing are dependent on interacting with a healthy natural environment.

Despite this, our society tends to treat the natural world solely as a resource to be exploited for our benefit. This shortsighted, extractive philosophy has resulted in the numerous environmental crises we face today: climate breakdown, ecosystems collapse, air and water pollution, biodiversity loss, deforestation, industrial fishing, intensive agriculture and plastic waste. These are all detrimental to human health and some threaten our very survival.

Air pollution for example, is a massive global public health issue. Pollutants from vehicle emissions, industry and fossil fuel combustion are responsible for millions of deaths worldwide from cardiovascular disease, asthma and lung cancer. It is also thought to be a risk factor for neurodevelopmental problems in children and neurodegenerative diseases in adults.

Climate change is said to be the biggest global health threat of the 21st Century, causing food and water insecurity, morbidity and mortality from heat waves, droughts and floods, and mental health problems arising from such extreme events.

Biodiversity loss is a less well-publicised, yet incredibly important health problem. Biodiversity refers to the huge variety of life on earth; not simply species, but also genes and ecosystems.

It’s estimated that there are about 15 million species on Earth; so far we’ve identified approximately 1.9 million. The background or natural extinction rate of species is approximately 1 per million per year, however the current extinction rate is thought to be 100-1000x greater than this due to human activity.

This level of global biodiversity loss is massive and unprecedented. We are in the throes of the earth’s 6th mass extinction event, however for the first time it is caused by human activity: mostly by habitat destruction on land and in the oceans through deforestation, bottom trawling, damning and dredging of rivers and drainage of wetlands. There are other human caused drivers such as pollution, the introduction of invasive species and climate change, which is likely to exceed habitat loss as the most significant threat in the not too distant future.

Why should all this matter to us, aside from the fact that we have a moral obligation to act as stewards of the natural world?

Biodiversity underpins ecosystem function and is therefore essential for providing all the life-support services mentioned above. It also represents a huge, mostly untapped source of potentially life-saving drugs and medical research. Over half of all drugs developed over the past 25 years are either derived directly from, or modeled after natural compounds: morphine, aspirin, warfarin, antibiotics, chemotherapy drugs, ACE inhibitors and AZT, to name but a few.

Despite the many medical breakthroughs we’ve derived from nature, we’ve barely begun to scratch the surface of what it has to offer mankind, yet we continue to allow our greatest repositories of biodiversity to be degraded or even lost forever. Rainforests are being cleared at alarming rates for agriculture, cattle ranching and timber; 17% of the forest in the Amazon has been lost over the past 50 years. Coral reefs are being destroyed by ocean warming and acidification, as a result of climate change. Who knows how many potentially life-saving discoveries have been wiped permanently from existence?

When we start to view environmental problems in this way (i.e. as a public health emergency), it becomes clear that those of us in the healthcare industry have a responsibility to start addressing environmental degradation.

As healthcare practitioners, we are ideally placed to educate our patients, students and the public about the inextricable links between the environment and human health; to promote sustainable, low carbon behaviour; and to convince policy makers that robust environmental legislation is urgently required, as is health promoting infrastructure, such as active travel networks and access to urban green spaces.

If we’re going to start engaging in environmental advocacy, then we’ll have to adopt an evidence-based approach where possible, as we do for the rest of our practice. However, in the face of life threatening problems, it is inappropriate to postpone preventive measures while we wait for full scientific certainty. This is known as the precautionary principle, and it is a key component of environmental decision-making.

Having said that, much evidence now exists to support the assertion that our physical and mental health depend on our interaction with nature. A variety of studies suggest that contact with nature reduces mortality from all causes, alleviates stress, improves mood and self esteem, increases levels of physical activity, increases concentration, reduces symptoms in mental health patients and children with ADHD, and reduces indicators of physiological stress such as pulse rate, blood pressure and cortisol levels.

Urban greenspace (i.e. any vegetated land such as parks, gardens, woods and wetland within an urban area) has also been shown to increase social interaction, reduce health inequality, reduce crime rates, and improve air and noise quality. Interestingly, it’s thought that as the species richness of an area increases, so do the psychological and physical benefits.

At this stage, although extensive, the evidence is of varying degrees of quality. Some of it is short term, with surrogate end points, sampling bias and self reporting. Most of it is correlational. It also tends to be biased towards higher latitudes (ie. North America and Europe) and Western Societies. Clearly there is more work to be done, however, the overwhelming majority of these studies show a positive association between interaction with natural environments and human health measures.

Of course, if health professionals are going to take a leadership role in advocating environmental protection and promoting sustainable, healthy, low-carbon behaviour, then we also need to get our own house in order. The NHS is a major emitter of CO2, and is responsible for approximately 25% of total public sector emissions. It also generates huge amounts of waste, the vast majority of which ends up in landfill.

The healthcare industry has the opportunity to set an example to the rest of the population:

We could build energy efficient hospitals powered by renewable sources, incorporating green space for patients, staff and the local community to use for exercise, rest and relaxation. We must significantly reduce our waste through more appropriate procurement, waste segregation and recycling. Hospital should be sourcing healthy, seasonal, local food; promoting active travel and public transport for staff and patients; and providing incentives for staff to reduce their ecological footprint.

I’ll leave you with a final quote to ponder:

The future will be green, or not at all

– Bob Brown (Australian politician, environmentalist and doctor)