The Science Behind How Your Diet Affects the Environment

We currently live in an age of eco-consciousness where more individuals than ever want to know not only where but how all of the items they purchase are produced. And when it comes to our food consumption, the keywords tend to be organic, free range and fair trade. Many people even give up or reduce the amount of meat they consume for environmental purposes. Now, the findings from a recent study may add another criterion to determine whether the food we eat is truly environmentally friendly.

According to a recent article in Scientific American by Brittany Patterson, a new study by researchers at Carnegie Mellon University states that if Americans followed the Agriculture Department’s 2010 dietary recommendations (more fruits and veggies, whole grains, and seafood), energy use would rise by 38 percent, water use would increase 10 percent, and there would be a 6 percent increase in greenhouse gas emissions. Essentially, food that may be categorized as healthier for humans may not be as “healthy” for the environment (case in point: eating lettuce gives off three times the greenhouse gas emissions than consuming bacon does). “You cannot just jump and assume that any vegetarian diet is going to have a low impact on the environment,” says Paul Fischbeck, a professor of social and decision sciences and engineering and public policy who is also a co-author of this study. “There are many that do, but not all.”

The researchers analyzed more than 100 foods to obtain information about their water use, energy use, and emissions. Here are some of their findings:

  1. Fruit is responsible for the most water and energy consumption per calorie.
  2. Meat and seafood give off the most greenhouse gas emissions per calorie.
  3. Some vegetables (like lettuce) have large environmental footprints, while others (like Brussels sprouts) do not.
  4. Beef was 3.5 times more taxing on the environment than pork products like bacon.


“If you totally forget health, which diet would have best impact on the environment?” Fischbeck asks. “You’d eat a lot more fats and sugars.” He says the conclusion is that we should be assessing each food item on a case-by-case basis. This will be an important topic as the USDA is set to release its 2015 Dietary Guidelines in a few days, and this proposal will affect not only the food purchased for the federal school lunch program, but also our federal nutrition policy for the next five years. And as we begin to create our own 2016 diet, we can keep these discoveries in mind.

For bacon lovers who want to incorporate some more pork into their diet, buy Bacon Nation: 125 Irresistible Recipes

Would you tweak your diet based on this study’s findings?