By Kerri-Ann Jennings , July 18, 2011 - 3:43pm
If you’ve ever found yourself arguing about whether eating meat is healthy for you and the planet and, if so, which meat to eat, you now have some answers. The Environmental Working Group (EWG) , which brought us the “Dirty Dozen,” a list of the 12 most pesticide-ridden fruits and vegetables , released a report today showcasing the carbon footprint of 20 conventionally grown popular protein sources, from lentils to lamb.
To come up with the carbon impact, the EWG  looked at the food’s full “lifecycle”—including the water and fertilizer to grow feed crops, transportation of the food and even the amount of food that’s wasted.
The biggest take-away: eat less meat and avoid wasting it (20% of edible meat ends up being tossed). Why should you care? The implications of this report are twofold—environmental and personal health. On the environmental side, the United Nations recently determined that livestock is one of the top contributors to the world’s most serious environmental problems. Going meatless can reduce water pollution, waste and greenhouse gases, and save energy, land and water. As for personal health, science shows that eliminating or cutting back on meat may improve blood pressure, decrease your risk of heart disease, lower cholesterol and help better manage your weight.
The EWG ’s full list of 20 “meats and other protein” sources includes vegetables like broccoli and tomatoes that, while having a low carbon footprint also deliver very little protein (around 1 to 2 grams per serving). So to bring you the 5 best and 5 worst proteins, I’m sticking to the EWG ’s abbreviated pocket-guide version and annotating with my own comments as a registered dietitian and associate nutrition editor at EatingWell Magazine. To find out what ranked best, worst and in between on the full list of 20 protein choices, click here. 
5 Worst Protein Choices for the Environment
Lamb’s carbon footprint comes mostly from the methane the animals produce through digestion and manure and from the crops grown to feed them. The same is true of cattle (which is why beef ranks second in the list of top 5 carbon offenders), but since lambs produce less meat, the carbon footprint is greater per ounce. In fact, eating 4 ounces of lamb is equivalent to driving 13 miles, in terms of your carbon footprint.
What you can do: Lamb isn’t widely eaten in the U.S. and in terms of carbon emissions that’s a good thing. Keep eating it sparingly, according to the EWG.
Like lambs, beef cattle are ruminants and produce the same greenhouse gases while digesting their food. Conventionally grown beef cattle are also shipped during different stages of production, adding to their environmental toll.
What you can do: When you do choose beef, look for grass-fed and organic. While pricier than conventional, it’s a healthier choice for you and the environment. Grass-fed beef is richer in heart-healthy omega-3 fats. Plus, organic, grass-fed cattle are raised in a way that minimizes the carbon emissions from manure. The EWG also recommends avoiding processed beef products, such as sausage, since more processing means a bigger carbon footprint and the processed products are less healthy than unprocessed.
Must Read: 5 Myths About “Natural” Meat Busted 
I adore good cheese, so I was deeply saddened to see cheese come in at number 3. I was momentarily heartened, though, when I noticed that EWG had compared all the proteins’ carbon emissions per 4 ounces. That ends up being a little less than 3 servings of cheese! Which means that if you stick to a serving, it’s more equivalent to eating 2 eggs, in terms of environmental impact.
What can you do: Stick to a single serving (1.5 ounces for hard cheese)—plus using a sharply flavored cheese can help you get the maximum impact for less. The EWG also recommends choosing organic and low-fat cheese, when possible.
Pigs don’t produce methane while digesting their food, but their manure contributes greenhouse gases. Processing and cooking pork adds to its carbon footprint.
What you can do: The EWG recommends choosing pastured pork, when you can, and avoiding processed pork (yes, that means bacon).
5. Farmed Salmon
Fish feed and electricity on fish farms adds to the carbon footprint of the fish. So does shipping, which means that wild salmon also has a higher carbon footprint when it’s shipped by air to your market. But don’t forget that salmon also delivers heart-healthy omega-3s, so still aim to eat fish a few times a week.
What you can do: Look for wild salmon over farmed, when possible. And don’t snub light tuna and sardines—other sources of omega-3s that have lower carbon footprints.
Don’t Miss: 6 of the Healthiest Fish and Shellfish to Eat, 6 to Avoid 
5 Best Protein Choices for the Environment
On the abbreviated top 10 list, milk came in with the lowest carbon footprint (lentils were lowest on the list of 20). However, the EWG looked at the carbon footprint of 4 ounces of milk—that’s only half a serving. So a full cup would be twice as high.
What you can do: Look for milk from local dairies, which should cut some of the carbon footprint caused by shipping. Milk from organic and grass-fed cows will also cut down on some of the carbon emissions caused by raising cattle, suggests the EWG, while delivering the added bonus of extra omega-3s and no growth hormones.
Beans are a smart protein choice. They give you fiber and healthy nutrients, such as folate and iron, and are very low in saturated fat. They’re also one of the best choices for the planet. Unlike animal-based proteins, beans have fewer carbon inputs and outputs (with animal proteins, growing crops just to feed the animals significantly adds to their carbon footprint).
Recipes to Try: Quick and Budget-Friendly Bean Recipes 
What you can do: Eat beans more often! If you want beans with the lowest carbon footprint, buy them dried, which skips the extra step of processing them.
Tofu’s carbon footprint (roughly one-third that of beef) largely comes from growing the soybeans and then processing it into tofu.
Healthy Recipes to Try: Quick Tofu Recipes 
What you can do: Tofu is a great choice, but keep in mind that if the label doesn’t say it is 100% USDA Certified Organic or non-GMO, there is a good chance it was made from genetically modified soybeans.
Feeding chickens, and the energy used on poultry farms, adds to the carbon footprint of eggs. But as far as animal proteins go, eggs’ carbon footprint is relatively low. In addition to protein, eggs give you some vitamin D and lutein and zeaxanthin, which are good for eye health. Although eggs contain some saturated fat and cholesterol, eating one a day shouldn’t raise your cholesterol levels.
What you can do: For the lowest carbon footprint, the EWG recommends opting for organic and pastured eggs, from chickens that are given organic feed and are allowed to run around.
Chicken is the best meat choice, but on the full list of 20 foods, chicken ranks 6th meaning that its carbon footprint is still higher than plant foods and tuna. From an environmental and health perspective, though, eating chicken is better than eating beef.
What you can do: Choose chicken more often than beef, pork or lamb. As with eggs, the EWG recommends choosing chicken that is organic and/or pastured.
What's your top consideration when buying meat and other protein sources?
Kerri-Ann, a registered dietitian, is the associate editor of nutrition for EatingWell Magazine, where she puts her master’s degree in nutrition from Columbia University to work writing and editing news about nutrition, health and food trends. In her free time, Kerri-Ann likes to practice yoga, hike, cook and bake.
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