Have you ever wondered how much a steak really costs – beyond its price tag at the deli? Beef’s cost on our environment far outweighs that of other meats, and some are saying that eating less red meat would be a better way to cut carbon emissions than giving up on your car.
In a new study, Weizmann Institute scientists claim that if the entire population of the US was persuaded to change their diet from a beef-heavy plan to one based on chicken, it would be possible to feed 40 percent more people – roughly 120-140 million – with the exact same resources.
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The researchers looked further than beef and compared the nutritional value of calories and protein derived from various meats, with their environmental cost. The latter included the amount of land needed for fodder or grazing, and the emission of greenhouse gases in both growing the food and in growing the animals themselves.
Poultry yields more protein than beef
Chickens, according to the study, produce much more edible meat per kilogram of feed consumed, and they produce their meat faster than cattle, meaning more can be grown on the same amount of land. For every 100 calories and 100 grams of protein fed to beef cattle, the consumer ends up with around three calories and three grams of protein. For poultry, that figure is about 13 calories and 21 grams of protein.
The researchers, Prof. Gidon Eshel, Prof. Ron Milo and Alon Shepon, also asked what would happen if the entire US population was persuaded to adopt an entirely plant-based diet? That is, instead of using land to grow cow or chicken feed and then eating the animals, to use that land to grow nutritional crops – mainly legumes, including peanuts, soy, garbanzos and lentils. These can supply all of a person’s nutritional requirements (except vitamin B12, which can be obtained from nutritional yeast). A separate study, published in the journal Environmental Science and Technology, suggests that an extra 190 million people could eat off the same environmental resources in this way.
“If we changed our diet, we would change the environmental price we pay, with every meal,” Shepon said in a statement. “Eating a plant-based diet can both meet our nutritional requirements and save on land use, as well as the release of greenhouse gases into the atmosphere and excess nitrogen from fertilizers into the water supply. These are real costs that we all bear, especially when people eat beef.”
The research was recently published in the scientific journal Environmental Research Letters.
The data for the study came from figures for cattle and poultry breeders, and consumption statistics from the US.
Photos and video: National Geographic, Weizmann Institute