New plant-focused diet would ‘transform’ planet’s future,
say scientists
Red meat and sugar consumption needs to be reduced by half
around the world.
‘Planetary health diet’ would prevent millions of deaths a
year and avoid climate change
Damian Carrington Environment editor
@dpcarrington
Wed 16 Jan 2019 23.30 GMT Last modified on Wed 16 Jan 2019
23.32 GMT
The first science-based diet that tackles both the poor food
eaten by billions of people and averts global environmental catastrophe has
been devised. It requires huge cuts in red meat-eating in western countries and
radical changes across the world.
The “planetary health diet” was created by an international
commission seeking to draw up guidelines that provide nutritious food to the
world’s fast-growing population. At the same time, the diet addresses the major
role of farming – especially livestock – in driving climate change, the
destruction of wildlife and the pollution of rivers and oceans.
Red meat and sugar consumption needs to be reduced by half
around the world.
Globally, the diet requires red meat and sugar consumption
to be cut by half, while vegetables, fruit, pulses and nuts must double. But in
specific places the changes are stark. North Americans need to eat 84% less red
meat but six times more beans and lentils. For Europeans, eating 77% less red
meat and 15 times more nuts and seeds meets the guidelines.
The diet is a “win-win”, according to the scientists, as it
would save at least 11 million people a year from deaths caused by unhealthy
food, while preventing the collapse of the natural world that humanity depends
upon. With 10 billion people expected to live on Earth by 2050, a continuation
of today’s unsustainable diets would inevitably mean even greater health
problems and severe global warming.
Unhealthy diets are the leading cause of ill health
worldwide, with 800 million people currently hungry, 2 billion malnourished and
further 2 billion people overweight or obese. The world’s science academies
recently concluded that the food system is broken. Industrial agriculture is
also devastating the environment, as forests are razed and billions of cattle
emit climate-warming methane.
“The world’s diets must change dramatically,” said Walter
Willett at Harvard University and one of the leaders of the commission convened
by the Lancet medical journal and the Eat Forum NGO. The report, published in
the Lancet and being launched to policymakers in 40 cities around the world,
also concluded that food waste must be halved to 15%.
“Humanity now poses a
threat to the stability of the planet,” said Prof Johan Rockström at the
Stockholm Resilience Centre, Sweden, another author of the report. “[This
requires] nothing less than a new global agricultural revolution.” Farm yields
in poorer nations must be improved to create a sustainable, healthy world, the
report found.
The planetary health diet is largely plant-based and allows
an average of 2,500 calories a day. It allows one beef burger and two servings
of fish a week, but most protein comes from pulses and nuts. A glass of milk a
day, or some cheese or butter, fits within the guidelines, as does an egg or
two a week. Half of each plate of food under the diet is vegetables and fruit,
and a third is wholegrain cereals.
Willett said these provide the ingredients for a flexible
and varied diet: “We are not talking about a deprivation diet here; we are
talking about a way of eating that can be healthy, flavourful and enjoyable.
“The numbers for red meat sound small to a lot of people in
the UK or US,” he said. “But they don’t sound small to the very large part of
the world’s population that already consumes about that much or even less. It
is very much in line with traditional diets.”
The planetary health diet resembles those already known to
be healthy, such as the Mediterranean or Okinawa diets, the researchers said.
“The planetary health
diet is based on really hard epidemiological evidence, where researchers
followed large cohorts of people for decades,” said Marco Springmann at Oxford
University and part of the commission. “It so happens that if you put all that
evidence together you get a diet that looks similar to some of the healthiest
diets that exist in the real world.”
The report acknowledges the radical change it advocates and
the difficulty of achieving it: “Humanity has never aimed to change the global
food system on the scale envisioned. Achieving this goal will require rapid
adoption of numerous changes and unprecedented global collaboration and
commitment: nothing less than a Great Food Transformation.”
But it notes that major global changes have occurred before,
such as the Green Revolution that hugely increased food supplies in the 1960s.
Moves to tax red meat, prevent the expansion of farmland and protect swathes of
ocean must all be considered, the commission said.
Prof Guy Poppy, from the UK’s University of Southampton, and
not part of the commission, said: “This ‘call to arms’ with its clear solutions
is timely, comprehensively researched and deserves immediate attention.”
“This analysis is the
most advanced ever conducted,” said Prof Alan Dangour, at the London School of
Hygiene and Tropical Medicine, and also not part of the team. “But there is a
major question about the ability of populations to shift to such dietary
recommendations and their wider public acceptability.”
Prof Nigel Scollan, at Queen’s University Belfast and part
of the industry-backed Meat Advisory Panel, said: “This report tells us what we
have known for millennia: an omnivorous diet is optimal. In the UK, encouraging
people to eat less red meat and dairy will have little impact on the
environment and is potentially damaging to people’s health.”
But Richard Horton and Tamara Lucas, editors at the Lancet,
said in an editorial that global changes as set out by the planetary health
diet were essential: “Civilisation is in crisis. We can no longer feed our
population a healthy diet while balancing planetary resources. If we can eat in
a way that works for our planet as well as our bodies, the natural balance will
be restored.”
Avoiding meat and dairy is ‘single biggest way’ to reduce
your impact on Earth
Biggest analysis to date reveals huge footprint of livestock
- it provides just 18% of calories but takes up 83% of farmland
Damian Carrington Environment editor
@dpcarrington
Thu 31 May 2018 19.00 BST Last modified on Tue 20 Nov 2018
18.00 GMT
This article is over
7 months old
Cattle at an illegal
settlement in the Jamanxim National Forest, state of Para, northern Brazil,
November 29, 2009. With 1,3 million hectares, the Jamanxim National Forest is
today a microsm that replicates what happens in the Amazon, where thousands of
hectares of land are prey of illegal woodcutters, stock breeders and gold
miners. Photograph: Antonio Scorza/AFP/Getty Images
Avoiding meat and dairy products is the single biggest way
to reduce your environmental impact on the planet, according to the scientists
behind the most comprehensive analysis to date of the damage farming does to
the planet.
The new research shows that without meat and dairy
consumption, global farmland use could be reduced by more than 75% – an area
equivalent to the US, China, European Union and Australia combined – and still
feed the world. Loss of wild areas to agriculture is the leading cause of the
current mass extinction of wildlife.
The new analysis shows that while meat and dairy provide
just 18% of calories and 37% of protein, it uses the vast majority – 83% – of
farmland and produces 60% of agriculture’s greenhouse gas emissions. Other
recent research shows 86% of all land mammals are now livestock or humans. The
scientists also found that even the very lowest impact meat and dairy products
still cause much more environmental harm than the least sustainable vegetable
and cereal growing.
The study, published in the journal Science, created a huge
dataset based on almost 40,000 farms in 119 countries and covering 40 food
products that represent 90% of all that is eaten. It assessed the full impact
of these foods, from farm to fork, on land use, climate change emissions,
freshwater use and water pollution (eutrophication) and air pollution
(acidification).
“A vegan diet is probably the single biggest way to reduce
your impact on planet Earth, not just greenhouse gases, but global
acidification, eutrophication, land use and water use,” said Joseph Poore, at
the University of Oxford, UK, who led the research. “It is far bigger than
cutting down on your flights or buying an electric car,” he said, as these only
cut greenhouse gas emissions.
“Agriculture is a
sector that spans all the multitude of environmental problems,” he said.
“Really it is animal products that are responsible for so much of this.
Avoiding consumption of animal products delivers far better environmental
benefits than trying to purchase sustainable meat and dairy.”
The analysis also revealed a huge variability between
different ways of producing the same food. For example, beef cattle raised on
deforested land result in 12 times more greenhouse gases and use 50 times more
land than those grazing rich natural pasture. But the comparison of beef with
plant protein such as peas is stark, with even the lowest impact beef
responsible for six times more greenhouse gases and 36 times more land.
The large variability in environmental impact from different
farms does present an opportunity for reducing the harm, Poore said, without
needing the global population to become vegan. If the most harmful half of meat
and dairy production was replaced by plant-based food, this still delivers
about two-thirds of the benefits of getting rid of all meat and dairy
production.
Cutting the environmental impact of farming is not easy,
Poore warned: “There are over 570m farms all of which need slightly different
ways to reduce their impact. It is an [environmental] challenge like no other
sector of the economy.” But he said at least $500bn is spent every year on
agricultural subsidies, and probably much more: “There is a lot of money there
to do something really good with.”
Labels that reveal the impact of products would be a good
start, so consumers could choose the least damaging options, he said, but
subsidies for sustainable and healthy foods and taxes on meat and dairy will
probably also be necessary.
One surprise from the work was the large impact of
freshwater fish farming, which provides two-thirds of such fish in Asia and 96%
in Europe, and was thought to be relatively environmentally friendly. “You get
all these fish depositing excreta and unconsumed feed down to the bottom of the
pond, where there is barely any oxygen, making it the perfect environment for
methane production,” a potent greenhouse gas, Poore said.
The research also found grass-fed beef, thought to be
relatively low impact, was still responsible for much higher impacts than
plant-based food. “Converting grass into [meat] is like converting coal to
energy. It comes with an immense cost in emissions,” Poore said.
The new research has received strong praise from other food
experts. Prof Gidon Eshel, at Bard College, US, said: “I was awestruck. It is
really important, sound, ambitious, revealing and beautifully done.”
He said previous work on quantifying farming’s impacts,
including his own, had taken a top-down approach using national level data, but
the new work used a bottom-up approach, with farm-by-farm data. “It is very
reassuring to see they yield essentially the same results. But the new work has
very many important details that are profoundly revealing.”
Prof Tim Benton, at the University of Leeds, UK, said: “This
is an immensely useful study. It brings together a huge amount of data and that
makes its conclusions much more robust. The way we produce food, consume and
waste food is unsustainable from a planetary perspective. Given the global
obesity crisis, changing diets – eating less livestock produce and more
vegetables and fruit – has the potential to make both us and the planet
healthier.”
Dr Peter Alexander, at the University of Edinburgh, UK, was
also impressed but noted: “There may be environmental benefits, eg for biodiversity,
from sustainably managed grazing and increasing animal product consumption may
improve nutrition for some of the poorest globally. My personal opinion is we
should interpret these results not as the need to become vegan overnight, but
rather to moderate our [meat] consumption.”
Poore said: “The reason I started this project was to
understand if there were sustainable animal producers out there. But I have
stopped consuming animal products over the last four years of this project.
These impacts are not necessary to sustain our current way of life. The
question is how much can we reduce them and the answer is a lot.”
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