When biodiversity and human cuisine collide, even lentils and rice take a toll

Researchers painstakingly analyzed the biodiversity footprint of 151 dishes. They found that even the vegetarian ones can exact a high price.

By Warren Cornwall
February 28, 2024

What do Spanish lamb stew, Indian bean curry and Brazilian beef steak have in common?

While these dishes originate from around the globe and have very different ingredients, new research finds they all exact an outsized toll on global biodiversity.

Meat, particularly beef, has long been known to have a large environmental footprint. But the findings that such vegetarian mainstays as lentils and rice pose some of the biggest threats to biodiversity might come as a surprise.

It underscores the importance not just of what it takes to grow a particular kind of food, but also where it comes from. “Vegetarian dishes from highly biodiverse and under strong human pressure countries like India, can be also very detrimental for biodiversity,” said Roman Carrasco, a conservation scientist at the National University of Singapore who was involved in the new research.

The work takes a somewhat novel approach to scoring the environmental credentials of different kinds of food, one that reflects more clearly how people really eat. Rankings are often broken down by individual ingredient (for example, the carbon footprint of beef). But people usually don’t dine on single items. They combine them into meals.

So the scientists compiled a list of 151 of the most popular dishes from 25 countries with the world’s largest economies. They created the list based on “best of” articles about food from different parts of the world from CNN (Cable News Network), as well as Taste Atlas, a website that links foods to geographic locations.



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With the dishes in hand, the researchers then dissected the recipes. They adjusted each one so that the portions added up to the same number of calories. Then they tried to gauge the effect each ingredient in a dish would have on biodiversity in the places where it is produced.

That’s no mean feat, given the number of potential ingredients and the difficulty of figuring out how each one translates to the fate of species. For each item, the scientists relied on maps showing where different crops are grown or animals are grazed, and on estimates of how much land it takes to produce a certain amount of that item. To translate this into biodiversity, they turned to work by other scientists who have studied how agricultural production overlapped with species habitats.

In the end, Carrasco’s team came up with six different scenarios, depending on whether the ingredients came from nearby or around the world and the particular kind of effect on biodiversity (for instance, whether the effect was on rare species or all species).

A few patterns stand out. A meat-heavy recipe generally poses a bigger threat to biodiversity. That’s particularly true for beef, which demands some of the most animal feed or pasture. Among the 20 dishes with the largest biodiversity footprint, seven contained beef, more than any other item, the scientists reported last week in PLoS ONE..

Recipes from countries with lots of biodiversity posed a bigger problem. That means Brazilian beef dishes, such as picanha and fraldinha, held many of the top spots. That’s in part because the country is home to the Amazon jungle and Cerrado grasslands, both species-rich habitats threatened by agricultural expansion.

The penalty for food from biological hotspots also helps to explain why Indian recipes with legumes, such as dal, rajma and chana masala are more problematic than you might expect. Legumes and rice generally score very well, but the demands of feeding the world’s most populous country in a biologically rich area makes it a challenge. “The results show how hard it is to balance food production with a megadiverse country where 1.4 billion people live. It probably can’t be done much better and legumes are one of the best options to do so,” said Carrasco.

Many of the dishes that proved to be most benign in terms of biodiversity won’t win any awards from dietitians. The recipes are dominated by starchy vegetables such as potatoes and wheat, along with soybeans, corn, sugar and a variety of rather pedestrian fruits (apples, berries). Among the biodiversity champions are French fries, crumpets, baguettes and macarons.

That odd result is partly thanks to where these ingredients come from: temperate regions with lower levels of biodiversity.

There is also one big gap: seafood. Because of differences in how food production and biodiversity are measured on land and in the ocean, there are no fish dishes on the menu.

This new ranking could become another tool consumers can use to reduce at least some of the damage that comes from their appetite. Carrasco stopped eating beef several years ago because of the environmental effects. But the new research has him planning to forgo lamb for similar reasons.

While it would be wise not to let this new research be the sole guide to healthy eating, it could help eaters make meaningful changes, even by following some simple rules of thumb. It will have a familiar ring to those already trying to green their diets.

“Transitioning to a flexitarian, vegetarian or vegan diet is the most important recommendation,” to come from the research, said Carrasco. “Even simpler, I would avoid beef and lamb. That goes a long way.”

Cheng, et. al. “Biodiversity footprints of 151 popular dishes from around the world.” PLoS ONE. Feb. 21, 2024.

Image: ©Anthropocene Magazine