Each type of meat produced for consumption has a different sustainability footprint.
That sustainability footprint can be influenced by different factors.
In this guide, we look at the different factors that might impact how sustainable a type of meat is, as well as compare the sustainability of different meats to each other.
This guide is a complementary guide to our more comprehensive guide about the sustainability of all foods.
(Note – this is general information guide only. It is not health advice, and is not a substitute for the advice of a qualified health professional)
Summary – What Is The Most Sustainable Meat To Eat?
Which Meat Is Most Sustainable?
– Carbon Footprint
To look at one sustainability indicator …
Beef and lamb have the highest carbon footprint by far, whilst chicken is one of the more sustainable meats in terms of carbon footprint, as well as farmed salmon, turkey and tuna
One study supports this point, indicating that ruminants like beef, cattle and goat may have higher carbon footprints per gram of protein produced than aquaculture, fisheries, pork, poultry and plant based foods.
– Water Footprint
Looking at another sustainability indicator …
Beef, pork and lamb have higher water footprints than chicken
The sustainability footprint of seafood can different depending on the fishing method used – even ocean based aquaculture and fishing methods like trawling can have a significant environmental impact, but, that impact is specific to the ocean (compared to land based agriculture which impacts soil, fresh water, air pollution, and so on).
– Conversion Efficiency Of Feed
How efficiently animals convert feed can impact aspects of sustainability such as how efficiently they use resources
Some sources indicate that some types of on-land aquaculture have a greater conversion efficiency of converting feed to protein compared to several forms of land based agriculture
– Wild Caught vs Farmed Meat
Wild caught food might be some of the most sustainable meat because there’s no resource and feed footprint that goes into producing animal (although, using a boat and burning fuel for example can make this footprint larger).
One example of wild caught meat might be Kangaroo in Australia – which according to some reports doesn’t use much water and has a small CO2 footprint (abc.net.au)
– Lab Grown Meat
There’s energy usage to run the labs, and lab grown meat still needs cells/tissue from animals as a source to grow the meat.
What Other Reports Indicate About The Sustainability Of Different Meats
Various other reports indicate that cattle/beef can be some of the most resources intensive meat to produce
Chicken can be more sustainable and less resource intensive according to some indicators
There’s some specific types of meat, like rabbit or some types of fish, can can rate as sustainable in different ways
Here is a selection of paraphrased quotes of from different sources had to say about the sustainability of different meats:
[Cattle requires the most land, food and time of any meat to produce] (bonappetit.com)
[Chicken in general might be more sustainable than beef, lamb and pork] (bonappetit.com)
Chicken and pork are more resource-efficient than beef (wri.org)
[Chicken and turkey do not produce methane, and need less food and water than sheep and cows. Although, slaughtering can be energy intensive, and the manure produced from intensively produced poultry can contain chemicals and pollutants] (ecoandbeyond.co)
[Rabbits may actually be one of the most sustainable meats to produce] (refinery29.com)
But, It Depends How Sustainability Is Being Measured …
The most sustainable meat to eat depends on how sustainability is being measured
Things like what sustainability indicator is being used, and what information/data is included and excluded in calculations can matter in the result
For example, water consumption, carbon emissions, water pollution, air pollution, and land use … are all examples of different sustainability indicators that can be measured
Each indicator might have a different type of meat coming out on top, and different variables to consider
There’s also the lifecycle of producing meat to consider – different stages are going to have different sustainability and environmental impacts.
For example, the farming or production stage might have a far bigger footprint than the transport/delivery stage (when doing a lifecycle assessment of meat)
So, a sustainability assessment should identify whether the entire lifecycle or just one stage are taken into account
Final numbers on sustainability of meat can also be influenced by the unit meat is measured by – by calorie produced, gram of protein produced, gram of fat produced, and so on
Variables That Can Impact Meat Sustainability
It depends on variables including but not limited to …
The meat production method/system used e.g. grass fed vs grain fed, factory farmed vs free range, land based vs water based, etc.
The time it takes for an animal to ‘reach weight’, and reproduction rate
Feed variables – the type and quality of feed, the amount of feed required, feed conversion efficiency, and other feed related factors
How waste is managed from the farm, or wherever animals are raised, transported, or processed
There’s also the issue of food waste to consider – some meats might be wasted at a higher rate compared to others at the consumer level e.g. land vs sea based meats
… along with a range of other factors
Considerations For Producing & Consuming Meat More Sustainably
Other than switching the type of meat someone eats, eating less total meat (especially beef, as well as lamb and goat), and adding certain types of plant based foods to a diet might be a more sustainable way to eat.
Eating less dairy might be another way.
According to some reports, what we eat (and what it takes to produce that food) might be the biggest sustainability factor, compared to whether the food product is locally sourced or comes with less plastic packaging
In the guide below, we’ve identified various things which might impact meat production sustainability on the producer’s side of the supply chain too.
Other Considerations Other Than Environmental & Resource Sustainability
It’s worth noting that meat has both health, and economic considerations as well
Meat needs to be profitable for producers, but, also affordable and healthy (adequate nutrition, and compatible with health requirements) for consumers.
So, sustainability isn’ the only measure of finding suitable meat to eat
The welfare of the animals during production is another factor to consider i.e. how human the meat production process is.
List Of Different Types Of Meat
Some of the more common ones might include:
Ocean & Freshwater Caught Meat
Aquaculture & Fish Farming (land based, and off land, as well as marine and fresh water)
Exotic Meats, & Wild Caught Meats
Sustainability Of Different Meats
Sustainability of any one specific type of meat depends on the sustainability indicator being measured.
Below is a summary of different meats across different sustainability indicators …
The production system under which meat is produced can affect the water footprint – for example, industrial systems with efficient feed conversion might be more water efficient than mixed or grazing systems.
Where the beef is sourced can impact the carbon footprint – countries with higher rates of deforestation may have beef products with higher carbon footprint.
Another study indicates that ruminants like, sheep and goats have a higher CO2e per gram of protein produced than other meats and foods.
The EWG.org resource in the resources list has a good graph showing the carbon footprint of different foods.
[One set of data puts GHG emissions per gram of protein produced for different meats (from most to least) at – ruminant meat (62 CO2e), recirculating aquaculture (30), trawling fishery (26), non recirculating aquaculture (12), pork (10), poultry (10), non trawling fishery (8.6).] (wikipedia.org)
In terms of metres squared of land used per unit of protein produced, the meats that use the most land (in order of most to least) are beef, pork, then poultry (chicken).
There are different types of agricultural land – arable vs grazing land for example – so the type of land being used should be specified, as some are more scarce than others.
[The biggest problem with beef, but also sheep and goat, is that they require large quantities of land and water per unit of protein and calorie produced and consumed] (wri.org)
Some seafood can be wasted in higher rates though depending on how fresh it is.
Pesticide & Fertilizer Use
Pesticide for example is sprayed on crops that eventually end up as animal feed.
The Meat Production Method Impacts Sustainability
For example, meat can be:
– Farmed vs wild caught
– There can be different fishing methods or aquaculture production methods used
… different meat production methods may lead to different sustainability footprints.
In the examples below, we see that some pasture raised meat can be more sustainable than some industrially raised meat, pole caught fish can be more sustainable than trawl or dredge caught fish, and fish farmed on land might be more environmentally friendly in some ways than open water farmed fish.
[Industrially produced meat uses land, crops, water, energy, and has an impact on the environment. It can also create animal welfare concerns]
[Farmers who produce pasture raised meat on the other hand can use certain farming techniques that might be more sustainable, and being pasture raised might be better for the animals too]
[The sustainability of seafood depends on the type of seafood, and how it’s produced, fished or caught]
[For example, the environmental impact of pole caught fish might be far less than trawl or dredged caught fish (can be issues with bycatches, and damage to ocean floor).]
[There might also be differences between commercial/large scale fishing which might bring into concern issues with overfishing, and small scale or individual level fishing.]
[Fish farmed on land might be more sustainable than open water farmed fish because they require no antibiotics, and their effluent come into contact with the surrounding marine environment. Waste water can also be cleaned and re-used] (linde-stories.com)
Animal Feed Has An Impact On Sustainability
Animal feed factors that can impact sustainability might include:
– Resources required to produce the feed (this guide outlines further how much resources livestock in general use in their production worldwide)
– The type and quality of feed
– The amount of feed animals need
– Feed conversion efficiency (i.e. how efficiently animals turn feed into meat or protein)
From the sources below, some summary points might be:
Free range can in some instances require more feed than factory farmed animals
Grass fed beef might be more resource efficient than cattle fed with crops that have to be grown
Chicken and pigs might be most efficient livestock at converting feed into meat or protein, followed by lamb, and then beef might be least efficient
Some sources say that aquaculture raised fish might convert feed to protein at the most efficient rates of them all
The quality of the feed is a variable in conversion efficiency though – for this reason, conversion efficiency in places like America and Europe where grain is used might be higher than in some places in Africa where feed quality on rangelands is poor.
Grass or hay fed cattle may convert at the most efficient rates
Both cattle and pigs can be fed on a range of feed
Some feed that comes from crops is grown using GM seeds
Resource Intensity Of Feed
[Animal feed plays a huge part in the sustainability of meat. The more resource intensive it is, and the less efficient animals are in converting it to meat that can be consumed, the less sustainable the meat might be] (refinery29.com)
Feed For Free Range vs Shed & Factory Farmed Animals
[Some reports indicate that some free range animals require more feed than shed or factory farmed animals, and therefore aren’t as green] (abc.net.au)
Grass Fed vs Crop Fed Animals
[Overall, grass fed beef might be more resource efficient than cattle fed from feed we have to grow] (abc.net.au)
Conversion Efficiency Of Feed
[The biggest problem with beef, but also sheep and goat, is that they are inefficient at converting feed to food …] (wri.org)
[For aquaculture …] The feed conversion ratio, which is the measurement of how much feed it takes to produce the protein, is 1.1. This means that essentially one pound of feed produces one pound of the protein.
Beef, pork and chicken’s feed conversion ratios vary between 2.2-10
Efficiency in livestock varies …
Chickens and pigs convert grain into meat at rates of two or three to one (i.e., it takes 2kg of feed to produce 1kg of chicken).
The ratio for lamb is between four and over six to one
Beef starts at five to one and goes as high as 20 to one.
[The efficiency of] various animals converting grain into protein is …
… cattle in feedlots [take about] 7 kilograms of grain to produce a 1-kilogram gain in live weight.
[Pork is] 4 kilograms of grain per kilogram of weight gain, [poultry is] just over 2 … And for herbivorous species of farmed fish (such as carp, tilapia, and catfish), it is less than 2.
Cattle that are grass or hay fed might convert at different rates i.e. the type of food an animal eats affects how quickly they put on live weight (extra kilograms)
Type Of Feed
[Pork … being omnivores means they can feed on food waste and scraps/leftovers] (bonappetit.com)
Chickens, pigs and other small animals can make use of waste and other by-products, eat worms or acorns, can complement food production and optimise the use of resources (globalagriculture.org)
Feed can include grains, roughages, soy and even cattle themselves (fed back to cattle for the protein). Some cattle even eat poultry manure.
Something else to note about feed in the United States is the prevalence of GMOs i.e. majority of GMO crops are used for livestock feed.
… chickens are the most efficient meat animal at converting grams of feed to grams of protein (idtechex.com)
[Pork need half as much feed as cattle …] (bonappetit.com)
The meat yield per cattle has increased by approximately one-third since 1961 (ourworldindata.org)
[For each kilo of protein produced, a cow in American or Europe will eat less hay and other dry matter on average than a cow on drylands in East Africa, and this is because of how poor the land is]
… traditional pastoralism [and] feeding cattle with grain would dramatically improve efficiency
Farmed Fish Specifically
[Of all the farmed organisms, fish might have the best feed conversion efficiency for several reasons to do with requiring less energy]
[Aquaculture involves] the efficient growth of fish … [and several key factors lead] to energy savings, which provides more available energy for growth, resulting in the highest feed conversion efficiency of widely domesticated animals
Other Variables To Meat Production That Can Impact Sustainability
There’s additional variables to consider to meat production including but not limited to:
– The length of time an animal spends on a farm, and how long they take to come ‘to weight’
– The reproduction rate of the animal
– How waste is treated or disposed of during meat production and processing
– The level of pollution or degradation from the production method
– Resources required for the production method
In the examples below, pigs and chickens can be efficient from a reproduction and growth rate perspective, with sheep being less efficient than pigs and chickens, but more efficient than beef.
[Sheep vs cattle:] Sheep come up to weight a lot faster and are less resource-intensive than cattle, but ewes usually have just one offspring a year, making them less efficient to raise than pigs or chickens, which reproduce much more frequently (bonappetit.com)
[Pork grows fast and has a reasonable reproduction rate]
[Chicken reproduces at a good weight, and gains weight quickly]
Potential Ways To Improve Meat Sustainability Footprint
There might be various ways for both consumers and producers to improve the sustainability from the production and consumption of meat or food diets in general.
Below are some general ideas, but are not definitive solutions:
Switch the type of meat being eat (say from beef to chicken)
Replace a % of meats in a diet with plant based foods. This guide contains information from a source that suggests that milk might be more efficient from a land, water and feed perspective per calorie or gram of protein produced
Eat foods that meet criteria for being sustainably produced – with just two examples being meat that is sustainably farmed, or fish that is sustainably fished. But, there can be many ways meat and other foods can be produced more sustainably
Don’t waste as much of the food that you buy
Buying locally produced food might decrease the transport/delivery footprint
[The biggest impact individuals can make isn’t eating organic over conventionally farmed, or eating local, or eating zero plastic packaging foods – it’s substituting meats like beef for more sustainable food like plant based proteins. Land use change is the biggest factor with food sustainability] (fastcompany.com)
[Eating less meat, and eating pasture raised meat over factory farmed/industrially produced meat, might be two ways to decrease the food footprint for an individual]
[Eating less meat can be one way to offset the increased price of pasture raised meat]
[Eating less meat and dairy is one way to lessen the environmental impact for an individual]
[People can cut their land footprint and GHG emission footprint by anywhere from 15 to 35 percent by reducing the amount of beef they eat from anywhere from a third to 70 percent]
Commit to meeting production-side sustainability criteria that lowers environmental impact, and improves other sustainability measures such as sustainable use of resources, protecting animal welfare and species numbers, and so on
[Farmers that use waste products from other food producers as part of the feed mix can be more green]
[Using the whole animal as opposed to just specific parts of the animal makes meat production more efficient and less wasteful]
[Some farmers use sustainable farming practices, compared to practices which might be used for profit or scale and might neglect sustainable practices]
Also Consider Health Of The Individual, & Economics In Meat Production
Separate to sustainability, environmental impact, and animal cruelty/animal rights – there’s the issues of human health, and economics aspects of meat to consider.
Economics, Production & Employment
Meat production has to be profitable for producers, but also accessible and affordable for consumers.
Meat also contributes to the economy and provides employment.
Poultry is cheaper to produce than other types of meat [and] Poultry also has fewer religious restrictions on its consumption than meats such as beef or pork (idtechex.com)
Health & Nutrition
Meat also has to meet the health requirements of the person eating it – it has to have adequate nutrition, but also be safe and fit in with any health requirements (such as health conditions, intolerances, and so on)
One example of health requirements is eating ideal sources of high quality proteins with a good amino acid profile.
Cereals and grains may not be an ideal source of protein for some people, and some plant based foods may not have complete protein profiles like some meats.
According the fastcompany.com: [Eating] a good balanced diet of legumes (peas, beans), tofu, nuts, and grains, you can certainly meet your protein needs
[People should take into consideration the daily recommendation for protein if they are worried that they aren’t eating enough meat -] 46 grams for women and 56 grams for men (foodprint.org)
33. Allen, P. J. & Steeby, J. A. (2011) Aquaculture: Challenges and Promise. Nature Education Knowledge 3(10):12, available at https://www.nature.com/scitable/knowledge/library/aquaculture-challenges-and-promise-23690921/