What part of a BLT do you think it's hardest on the environment to produce? Hint: It's not the meat. "Eating lettuce is over three times worse in greenhouse gas emissions than eating bacon," Paul Fischbeck says in a Carnegie Mellon press release. "Lots of common vegetables require more resources per calorie than you would think. Eggplant, celery, and cucumbers look particularly bad when compared to pork or chicken." A study co-authored by Fischbeck in Environment Systems and Decisions found that following USDA dietary recommendations calling for more fruits, vegetables, dairy, and seafood is actually worse for the environment. "If you totally forget health, which diet would have best impact on the environment?" Fischbeck tells Scientific American. "You'd eat a lot more fats and sugars."
Researchers found that if every American followed the USDA's 2010 guidelines on diet and calorie intake, it would use up 38% more energy and 10% more water and create 6% more greenhouse gas emissions. "What is good for us health-wise isn't always what's best for the environment," Fischbeck says. But that doesn't mean it isn't possible to have an environmentally friendly vegetarian diet. Scientific American reports onions, carrots, broccoli, and Brussels sprouts are some of the least-taxing foods to produce. And a Huffington Post blogger stresses the distinction: "The researchers didn't find that vegetarianism is bad for the environment," she writes. "They found that not every plant product is more environmentally friendly than every meat product." The USDA is expected to release its new dietary guidelines in a few days, and Fischbeck says it needs to look more closely at individual foods and the impact they have on the environment. (But experts say this is the best diet for weight loss.)