May 7, 2018

How the Impossible Burger Stacks Up on Nutrition and Sustainability

Jessi Silverman

Jessi Silverman

Research Assistant

Johns Hopkins Center for a Livable Future

Patrick Brown, the founder of Impossible Foods (IF), has what may be an impossible-seeming goal: to make meat obsolete. His vision? To create “…uncompromisingly delicious and nutritious meat and dairy products that do not require vast expanses of grazing and feedcrop lands,” and that will win the marketplace against meat. And because meat substitution with plant-based foods could be one strategy to reduce diet-related disease and the environmental burden of animal agriculture, it’s a worthy goal.

Unlike any veggie burger to come before it, the Impossible Burger has perhaps come the closest to imitating the eating experience of ground beef. How? IF’s major discovery was the single compound that is responsible for the authentic meaty flavor missing from the other plant-based burgers on the market: heme.

Heme, which is found most concentrated in animal flesh, is the catalyst for hundreds of chemical reactions that occur while a burger is cooking. These reactions produce fragrant compounds that combine to convey to your brain the taste of cooked meat. In order to supply heme sustainably for burger production, IF developed a yeast strain that is genetically modified to produce a heme-containing protein made by soybean plants in nature. The ingredients that make up the bulk of the burger are more easily accessible: wheat protein, coconut oil and potato protein.

Curious to sample it myself, I recently ate an Impossible Burger. Not having eaten a beef hamburger in close to five years, the plant-based patty did not exactly line up with what I remember. That being said, it was flavorful, meaty, satisfying and certainly looked just like a hamburger, inside and out.

Now available in more than 1,000 foodservice establishments across the country, it seems that the Impossible Burger is truly a better choice for the planet than a typical beef hamburger. Based on a Life Cycle Assessment comparison of the total supply chain of the Impossible Burger versus a “traditional bovine burger from average U.S. production systems,” the Impossible Burger takes a smaller toll on resources and climate: it’s associated with 25 percent of the water use of a hamburger, 5 percent of the land use and 13 percent of the greenhouse gas emissions.

But what are the environmental implications of widespread adoption of the Impossible Burger as a meat substitute compared to other alternatives? Some researchers modeled several different scenarios in which 10, 25 and 50 percent of protein in the average US diet and archetypal vegetarian and vegan diets was replaced with the Impossible Burger. They compared the greenhouse gas, land and water footprints of the different scenarios based on Life Cycle Assessments. All three metrics improved compared to the mean US diet progressively with increasing protein replacement by the Impossible Burger.

But—and this is an important point—compared to the typical vegetarian and vegan diets, protein substitution with Impossible Burger increased greenhouse gas emissions and marginally increased water and cropland use. This result stems from the additional energy inputs in the Impossible Burger production processes compared to the soy and nut-based foods that supply most vegetarians’ protein. The authors concluded that reducing food-related environmental pressures requires omnivores to incorporate plant-based meats like the Impossible Burger into their diet, rather than vegetarians and vegans. They also pointed out that Impossible Burger production is associated with greenhouse gas emissions comparable to non-beef meats, but that it avoids other harms of animal agriculture, namely the overuse of antibiotics and excessive waste production that disrupts the surrounding ecosystem.

Some might argue based on this data that the ideal alternative to red meat is a vegetarian diet. However, given that taste has so much influence on people’s food choices, swapping a hamburger for something nearly identical is probably more realistic than the ideal—expecting everyone to take up tofu.

Surprisingly, the question that no scientist, journalist or marketer seems to be asking is whether widespread replacement of hamburgers with Impossible Burger would be beneficial for the eaters’ health. In fact, despite the negative health outcomes associated with high red meat consumption, IF touts the nutritional similarity of the Impossible Burger to a standard 80 percent lean hamburger. Specifically, promotional material emphasizes they are equivalent in terms of the nutrients consumers tend to value most in beef: protein and heme iron. But this advertisement about the Impossible Burger containing heme iron is curious, because excess intake of highly bioavailable heme iron is linked to cancer, coronary heart disease, and diabetes. (Meanwhile, the protein content from wheat and potatoes is likely to be more healthful than beef protein.) And although the Impossible Burger is devoid of cholesterol, its saturated fat content is also comparable to a hamburger, presumably due to the coconut oil. The Impossible Burger also lacks dietary fiber, which is responsible for some of the health benefits attributed to other plant-based protein sources. So although by a few measures the Impossible Burger may be nutritionally superior to the standard hamburger, the nutritional composition does not suggest that it is as healthful as replacing meat with whole plant foods.

All told, with respect to nutrition and sustainability, the virtue of the Impossible Burger mainly rests on its being taken up widely as a replacement for meat—if it is embraced by those for whom a vegetarian or vegan diet is not an option, it could have a meaningful impact.

Photo: Jessi Silverman, 2018.


  1. Posted by Matthew Engel

    The Impossible Burger is not available for retail purchase by consumers as of May 2018, but I suspect the combined effects of (1) manufacturing costs, (2) novelty factor, and (3) aura of healthfulness will make this product dramatically more expensive on a per-lb basis compared with 80/20 ground beef (USD ~$3.70/lb).

    Even the savviest of ecosustainability-minded omnivores may not stomach a $5 mark-up on a merely beef-esque product. But I’ll withhold my judgment for now – besides, the product itself is an amazing feat of food science unto itself!

  2. What about the 10 g of Saturated fat from the coconut oil? That is a known health risk.

  3. Posted by Bob Chitester

    Jesse, As an 80 year old fighting stage four prostate cancer, the impossible burger is a delightful option. And it is clearly a step in the right direction and a significant scientific achievement that can lead to “more perfect” alternatives. In developing countries it can be the salvation of the natural habitat being destroyed to raise feed animals. And from the consumer’s perspective, vegan or otherwise should remember biochemist Bruce Ames’s admonition that the demon of any health risk is in the “dose.” Kudos to Patrick Brown.

  4. Posted by Cynthia Racette

    Can you please address the sodium content of Impossible Burgers for those of us who are on a low sodium diet?

  5. Posted by Earl Roethke

    These won’t be part of my diet until they come in a low (better no) sodium option.

  6. Both the Impossible Burger and the Beyond Burgers, have just as much saturated fat (whether via animal or plant-based) as a regular hamburger. And, they have just as many calories. I haven’t eaten beef in 30 years; and although both burgers are impressive, I’m sticking with my 70-calorie per patty faux turkey Boca Burger.

  7. Posted by Louise

    Most meat is processed or purchased from CHINA so that “all-beef patty” could be dog meat. I’ll stick with my vegan diet, thank you.

  8. Posted by Louise

    I tried the impossible burger without mayonnaise and still was too filling/fattening. I won’t be eating it again.

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