What’s going on here? How could this possibly be? Basically, the researchers decided to measure the environmental impact of meat vs. veggies in the most misleading way imaginable: by comparing the highest-calorie meats to the lowest-calorie vegetables.
Let’s accept this study’s findings that lettuce in fact generates three times the greenhouse gas emissions per calorie as bacon to see where that gets us. Suppose you were to eat four slices of bacon. That’ll give you 468 calories worth of bacon before it gets pan fried. How much shredded green leaf lettuce would you need to eat to reach 468 calories? Oh, a mere
93 cups.
Since 93 cups is an insane amount of food, and hard to envision, let’s simplify it. That amount of shredded lettuce will fill a standard full-sized grocery bag almost to the brim, and weigh 7.3 pounds.* I hope you’re hungry! The reality here is clear: if you’re trying to meet your caloric needs by eating lettuce, you, sir or madam, are a lunatic.
That lettuce is full of vitamin A and fiber. And unlike bacon it’s fat-free, and has no association whatsoever with
colorectal cancer.
I don’t see anything in the study’s notes that acknowledges meat industry funding, but it’s hard to imagine that using the calories of lettuce vs. meat is a good-faith and honestly-intentioned way to analyze this issue. You don’t eat vegetables—especially super low-calorie items like lettuce, cucumbers, and eggplant (which one of the coauthors
calls out by name)—for the calories. You eat them for the taste, the fiber, the nutrients, and the fact that higher vegetable consumption has a
strong association with better health. And you certainly don’t go eating 93 cups of lettuce in a sitting.