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If everyone in the world ate like Americans, we’d run out of land to grow food

Dietary rules need to consider the land needed to grow the food, cautions new study.
Rachel Fleagle (R) her sister, Jessica and Scott Staub, all of Philadelphia pose with the burger May 5, 2005 at Denny's Beer Barrell in Clearfield, Pennsylvania. (Photo by Jeff Swensen/Getty Images)
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A new study shows that USDA dietary guidelines are, ultimately, unsustainable for the planet. We’d need much more land if people ate according to the recommended diet globally. In fact, we’d be missing a chunk of land the size of Canada. 


Researchers from the University of Guelph and the University of Waterloo in Canada concluded that an additional gigahectare of fertile land would be necessary to feed everyone if USDA rules were the norm around the world. The scientists did not necessarily want to single out the U.S. only as these issues are much wider in nature. The USDA guidelines were more readily available when the research began six years ago.

The larger point the scientists make is that guidelines for food should be based not just on nutrition. The issue of sustainability and how much land is used up to produce food is important to consider, especially with the population growing rapidly worldwide. 

“Our analysis shows that there is not enough land for the world to adhere to the USDA guidelines under current agricultural practices,” the scientists wrote in the study. “This is despite the fact that the USDA guideline diet is already less land-intensive than the current U.S. diet.”

The researchers utilized current yield data for various crops from the Food and Agriculture Organization of the United Nations to arrive at their estimates. They wanted to gauge how much land would be needed to grow what the USDA says is a healthy diet that is low in calories and saturated fats.

Here are the current USDA guidelines:


The scientists, who includedMadhur Anand (professor of global ecological change and sustainability at the University of Guelph) as the study’s senior author,propose that health should not be the only consideration when setting guidelines. Navin Ramankutty, a professor of global food security and sustainability at the University of British Columbia, who was not involved in the study agreed:

“A health guideline only focuses on what kind of macro nutrient people get. They’re just going to say, ‘OK, you need to consume so much protein.’ It’s not going to say where that protein source should come from,” said Ramankutty. “And for sustainability, it makes a huge difference where the actual protein comes from, and I think to point that out is very useful.”

While highlighting the issues of food production sustainability with regards to the USDA diet, the study did point out something positive about them. Most Western countries would use less land if they adopted such rules. Australia, Brazil and the United States (which doesn’t exactly follow the guidelines) would “spare” the most land, while India, Mozambique, and Saudi Arabia would need the most land to meet the USDA rules.

The study’s co-author Evan Fraser, the Canada Research Chair in global food security, called their findings a “wake-up call” while highlighting that there is also a path forward.

“Feeding the world over the next generation is one of the biggest global challenges that we face,” said Fraser. “And this is not an easy problem to solve. It’s right up there with climate change and international trade issues and all these big, thorny issues of the 21st century.”

He suggests that we would need to consider changes like moving to diets higher in fruits and vegetables and switching to plant-based proteins. It’s also important to make less waste and invest in science in order to increase the yield of crops, said Fraser, according to CBC News.

Check out the new study published in PLOS One here.

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