Taking the USDA’s advice and eating a diet heavy on fruits and veggies may be good for us, but it may not be as good for the Earth. A group of Carnegie Mellon scientists calculated the environmental impact of healthy diets, and they argue in a new paper that some vegetables’ energy use and gas emissions are worse for the climate than people realize. One author explains that on a per-calorie basis, “Eating lettuce is over three times worse in greenhouse gas emissions than eating bacon,” and they call their findings “perhaps counterintuitive.”
It’s well established that meat isn’t great for the environment, and the authors point out that beef is still worse than lettuce, but pork and chicken are practically Al Gore in a Prius next to celery and eggplant. “There’s a complex relationship between diet and the environment,” lead author Michelle Tom explains. “What is good for us health-wise isn’t always what’s best for the environment. That’s important for public officials to know and for them to be cognizant of these tradeoffs as they develop or continue to develop dietary guidelines in the future.”
Critics have called the study deceiving, since a calorie of lettuce goes a lot further than a calorie of bacon, but the researchers also evaluated the USDA recommended diet (which is heavy on seafood and dairy) and found that a healthy diet uses 38 percent more energy and increases greenhouse gases by 10 percent. Yikes.