Eggs, Dairy, Poultry, Beef, or Pork. Which is the Worst?

A new paper compares eggs, dairy, poultry, beef and pork to determine which has the biggest environmental impact.

If you guessed beef, you’re right.

Yet another study has confirmed that beef is the most environmentally harmful animal product the American diet. Beef production uses the most water, land, and nitrogen fertilizer while producing more greenhouse gas when compared to pork, poultry or eggs in a per-calorie comparison. Even dairy was found to be less resource-inefficient when compared with beef.

The authors find that producing one calorie of beef uses 11 times more water and six times more nitrogen fertilizer than the other animal products. Poultry, pork, eggs and dairy were found to use relatively similar resource levels.

PNAS, “Land, irrigation water, greenhouse gas, and reactive nitrogen burdens of meat, eggs, and dairy production in the United States”/via

According to the paper, about 40 percent of the total land area of the United States is currently dedicated to the production of animal-based products. That includes the land needed for pasture, as well as feed crops. Much of this land could instead be dedicated to crops that are directly consumable by humans, and would require fewer resources per calorie.

Interestingly, the authors make an augment against the idea that cattle ranching often occurs in arid parts of the West, which is unfit for most crops. They argue that these grasslands could provide other ecological benefits if they weren’t being farmed, particularly by enhancing biodiversity and creating wild habitats.

You may be wondering about eating fish—which can also have negative impacts on the environment. This paper did not analyze seafood for two reasons: a lack of comprehensive data and because sea food only accounts for 0.5 percent of the calories consumed by the average American.

This new analysis may help people make more informed choices when it comes to making purchasing decisions. While many of our readers opt to cut animal products out of their diets, this research makes it clear that not all meat has the same impact.

The authors also hope their findings can steer policy makers when it comes to farming and food security decisions. “Because our results reflect current US farm policies and agrotechnology, the picture can change markedly in response to changes in agricultural technology and practice, national policies, and personal choice,” they write.

The findings were published today by the Proceedings of the National Academy of Sciences. Researchers from a number of different institutions collaborated on the project: Gidon Eshel of Bard College, Alon Shepon and Ron Milo of the Weizmann Institute of Science in Israel, and Tamar Makov of Yale University.

Written by Margaret Badore, originally on TreeHugger.

Photo Credit: TreeHugger


Dt Nc
Dt Nc2 years ago

According to the chart, if you are going to consume animal protein eggs is the least environmentally damaging. It is also one of the best protein for you because about 50% of the protein are bioavailable to your body. Most other proteins are used less efficiently. Hence, athletes and body builders tend to eat lots of eggs or egg whites.

Elena Poensgen
Elena Poensgen3 years ago

Thank you

Mary Donnelly
Mary Donnelly3 years ago


Val M.
Val M3 years ago


Elena P.
Elena Poensgen3 years ago

Thank you :)

Dale O.

That was accurate, Carol P, when you had mentioned that eggs from non-factory farms would eliminate much of the problem, plus the fact, eggs from factory farms don't taste as flavourful when compared to the flavour of other eggs not from a factory farm.

It is a certainly a good idea to avoid anything that comes from a factory farm.

Since not everyone lives in the States, American statistics don't always apply to the farming situation in every country.

Since I am omnivore, vegan substitutes for eggs are not always something that I would prefer to eat. When I want an egg, it is a real one.

Sonali G.
Sonali G3 years ago

I am the closest to vegan now than I have ever been in my life. I wont buy eggs but occasionally eat quorn (as much of an egg as I can consume without upsetting my gut) I wont drink milk but no doubt have consumed things that are manufactured near milk products as to be called 'vegetarian' rather than 'vegan' on the label. I haven't eaten any animal, meat or fish since 1992 and never will again. I could never go back to that way of life. I seem to be surviving quite well eating lots of fruit and veg and nuts and pulses. I take supplements but although I may need them as I have been ill, I think that I am on a far superior diet now and I am probably healthier than ever before. One of the reasons for this is that you do have to think about what you are eating and put a bit of effort in to it. I think that it is a mistake to be a meat eater and assume that you will automatically be getting everything that you need when so many meat eaters are thoughtless about what they consume and their diet is stodge and processed junk. My partner eats meat (much to my disappointment but each to their own) and his habits are terrible. I am onstantly trying to encourage him to eat a bit of salad with his meals or some fruit. Sometimes he does thank goodness!

Rebecca Lynn Dreller
Rebecca Lynn D3 years ago

@Alan- Truth hurts, doesn't it. I have found that the majority of folks who scoff at vegan lifestyles, are in fact ashamed of their carnivorous ways and don't like to be reminded of the misery, suffering, damage to your own health, and environmental impact that eating meat produces. Don't you snarl at vegans and veganism, simply because it makes you more aware of the impact that your choices are making.

Marianne R.
Marianne R3 years ago

Thank you.

Clare Gorman
Clare Gorman3 years ago

amazing that in this day and age we still mass produce animals just to slaughter and eat them. They mean nothing to us .... its so sad :(