North American diets require more land than we have, study says

August 9, 2018 by Lori Bona Hunt, University of Guelph
Credit: Gary Csoff

If the global population adopted recommended North American dietary guidelines, there wouldn't be enough land to provide the food required, according to a new study co-authored by University of Guelph researchers.

The researchers found that global adherence to United States Department of Agriculture (USDA) guidelines would require one giga-hectare of additional land—roughly the size of Canada—under current farming practice. Their findings were published in PLOS ONE today.

"The data shows that we would require more land than what we have if we adopt these guidelines. It is unsustainable," said Prof. Madhur Anand, director of the Global Ecological Change and Sustainability lab where the study was undertaken.

"This is one of the first papers to look at how the adoption of Western by the would translate into production, including imports and exports, and specifically how that would dictate land use and the fallouts of that," she said.

Although the dietary guidelines are viewed as an improvement on the current land-intensive diet of the average American, the researchers say that dietary guidelines should be further developed using not just health but also global land use and equity as criteria.

"We need to look at diet not just as an individual health issue but as an ecosystem health issue," said Anand, a professor in U of G's School of Environmental Sciences (SES).

The authors found a strong east-west division worldwide. Most Western Hemisphere countries would use less land by adopting a USDA guideline diet, while most Eastern Hemisphere countries would use more land.

Co-authors of the paper are U of G Prof. Evan Fraser, holder of a Canada Research Chair in Global Food Security; SES graduate student Sarah Rizvi; Chris Pagnutti, an NSERC post-doctoral researcher in SES; and Prof. Chris Bauch, Department of Applied Mathematics, University of Waterloo.

"We need to understand human and environmental systems in a coordinated manner, and this is where the interdisciplinary aspect of the work shines. This is also why we worked with an applied mathematician," said Anand.

The authors call for international coordination of national dietary guidelines because global lands are a limited resource.

"This could be similar, at least in principle, to how greenhouse gas emissions are increasingly being coordinated internationally to address another major global problem: climate change," Anand said.

Fraser, scientific director of the Food from Thought project and director of the Arrell Food Institute at U of G, added: "One of the 21st century's great challenges is to develop diets that are both healthy for our bodies and sustainable for the planet.

"Developing the technologies and insights to help industry and consumers is part of what many of us at the University of Guelph are working on through the Food from Thought initiative."

Explore further: The environmental sustainability impact of foods in the national Dietary Guidelines for Americans

More information: Sarah Rizvi et al, Global land use implications of dietary trends, PLOS ONE (2018). DOI: 10.1371/journal.pone.0200781

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17 comments

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dogbert
2 / 5 (4) Aug 09, 2018
Why would anyone expect other countries to follow U.S. Dietary guidelines? We don't expect the U.S. to adopt. for example, an Asian diet.

Countries generally adopt diets appropriate to their population's preference, needs and available food sources.

We don't need to force a global diet on anyone.
V4Vendicar
3.4 / 5 (5) Aug 09, 2018
But according to Conservatives, Libertarians and the Wall Street Journal, the entire population of the world could comfortably live in an area the size of Texas, and therefore Overpopulation is a myth.

They wouldn't all be lying would they?

https://overpopul...-a-myth/
dogbert
5 / 5 (2) Aug 09, 2018
V4Vendicar,
I don't know anyone, conservative or liberal, who does not recognize that the world would face fewer problems if the world (certain parts of it) were not overpopulated.

I don't see how it is germane to this article other than the fact that we have so many people that some of those people have considerable food insecurity.
schultzy2012
1 / 5 (2) Aug 09, 2018
V4vendicar, like Dogbert I fail to see your point as it relates to this article. That said, as a matter of simple math, if you populated Texas (~261,231 square miles) with the population density of Paris, France (~55,673 per square mile), you would indeed be able to fit the entire world's population into the state of Texas. In fact, you could do so about twice over or do so at half the population density of Paris. If you used the entire area of the United States, every man woman and child on the planet could have a quarter of an acre to themselves. So yes, in terms of physical space, overpopulation is a myth; physical space is not an issue. Distribution, local governments, and resource allocation is another issue entirely; one highlighted by the difference between Paris, France and Caracas, Venezuela, despite Caracas having only a quarter the population density of Paris. Again, not sure what your point was though.
ShotmanMaslo
4 / 5 (4) Aug 10, 2018
So yes, in terms of physical space, overpopulation is a myth; physical space is not an issue.


Overpopulation is not about physical space, but about resources and ability to utilize them. A wealthy densely populated city is not overpopulated. A sparsely populated desert can be.

The argument about fitting into Texas is thus a sure sign that the speaker has no idea what they are talking about.
TheMuffinMan
1 / 5 (1) Aug 10, 2018
They were saying this exact same thing in the 50's when there were only 2 billion people on the earth. There's not enough resources to sustain us unless we depopulate! What you or these people can never account for is future developments.
TheGhostofOtto1923
not rated yet Aug 11, 2018
"The data shows that we would require more land than what we have if we adopt these guidelines. It is unsustainable,"

-NO, current population levels are unsustainable. The article is not telling you that the majority of the worlds population is malnourished.
unless we depopulate! What you or these people can never account for is future developments
And the future development was roe v wade and the subsequent ABORTION laws. ONE BILLION people and their dependents to the 3rd and 4th generation, never born. This in addition to the BILLION or so never conceived due to birth control, family disruption, and conflict.

And still, according to the article, there is not enough food to feed everyone properly.

Malthus was only documenting what Leaders had known for millenia.
antigoracle
not rated yet Aug 11, 2018
They were saying this exact same thing in the 50's when there were only 2 billion people on the earth. There's not enough resources to sustain us unless we depopulate! What you or these people can never account for is future developments.

Add to that, the US wastes 40 percent of its food, while sustaining a growing population, not only in numbers but also in weight, such that it's the fattest on the planet.
Whart1984
Aug 11, 2018
This comment has been removed by a moderator.
Whart1984
Aug 11, 2018
This comment has been removed by a moderator.
Parsec
not rated yet Aug 11, 2018
This article is based on simple math. Note however, that US dietary requirements are about calorie/protein etc. intakes and have nothing to do with what is actually eaten according to preferences. These requirements are based on what human beings need for adequate nutrition, and that remains a stable goal no matter what.

The amount of food grown on an acre however is quite variable. It is possible to produce 10x or more food on a per acre basis using intensive farming practices (aquaponics, greenhouses, etc.
Captain Stumpy
1 / 5 (1) Aug 11, 2018
@zeph
the rice actually represents the waster of water (which East Asia has enough from monsoon rainfall, but North America hasn't)
wrong https://academic....6/219797

there are other places with plenty of rainfall and water to allow for rice crop production as well
Whart1984
Aug 11, 2018
This comment has been removed by a moderator.
SURFIN85
not rated yet Aug 13, 2018
...so its not an excellent idea to eat the USDA pyramid? I live in the USA and for the last 30 years I've watched the diets of people (by observing what is bought in a checkout line) and their state of health (as they amble to and from their cars in the parking lots) and something like a total collapse of physical fitness has occurred.

The USDA pyramid is about as ridiculous a set of guidelines ever created.... You could tell people what is good for them until you're blue in the face- advice alone doesn't have much effect on addiction. A supermarket is chock full of addictive, irresistible products that aren't good for ya and to eliminate the bad stuff you'd have to expect people to walk past 95% of the stuff that will be sitting there screaming, "I taste really really good!!!" People don't really have that much willpower... Maybe the best alternative is a healthier substitute, like a lab grown meat, or substituting stevia for sugar, or limiting fat contents.
Captain Stumpy
1 / 5 (1) Aug 13, 2018
@zeph
The planting of rice in forests and mountains around Seattle is an excellent idea
not really
the point was that there are plenty of places in the US that have a rice crop and its not a waste of water
https://en.wikipe...tion.svg

By United States Department of Agriculture, National Agricultural Statistics Service - NASS USDANASS USDA, Public Domain

SURFIN85
not rated yet Aug 20, 2018
"North American Dietary Guidelines" are nowhere in evidence in the line at my local grocers. Judging by the general shape of the people, I'd say any guidelines are generally not followed
RealityCheck101
not rated yet Aug 31, 2018
Yay, more science based on data sets from people in ivory towers that don't know the first thing about food production let alone anything about soil health, water cycles and ecosystem function. These academicians are too busy looking at their computer screens to actually set foot in the field and realize that not all land is interchangeable. This is especially true with water use and edaphic conditions. One huge thing thus obviously not mentioned in the full study I perused is that we're rapidly running out of top soil. More intensification isn't going to help us. As Dr. David Montgomery has repeatedly demonstrated in his books and articles, if we truly want "to feed the world" we must restore healthy soils. This means restoring the soil biology which drives carbon, nitrogen and water cycles. When you do this, a lot more degraded land can be used for food production. Currently we're losing a lot of arable as our soils further erode..even as our populations continue to grow .

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