In the first episode of this series, it became clear that a completely vegan menu will save neither the climate nor biodiversity. In theory, more sustainable and animal-friendly solutions for agriculture and animal husbandry are conceivable. The reduced yield of those solutions does force meat reduction.

According to Imke de Boer, Professor of Animals & Sustainable Food Systems, we could eat about 9 to 23 grams of animal protein per day in the Netherlands, with a properly functioning system. Although the verdict has been passed on cured meats and we still don't know for sure whether red meat is healthy, the consumption of animal products in general has health benefits. For example, there is the theory that the human brain could never have evolved into what it is today without meat. We also need certain nutrients that we mostly get from animal products.

On the one hand, the question is therefore whether 9 to 23 grams of meat is sufficient and under what circumstances it is too little for people. On the other hand, the still growing world population and the limited area of land suitable for arable farming require solutions that take up little space.

Do those 9 to 23 grams of animal need to be sustainably supplemented to get a healthy amount of protein? If so, how? And are there other things we should be aware of in terms of health when we want to eat less animal products?

Because of these differences in protein quality, the Health Council recommends a 1.2- and 1.3-times higher protein intake for vegetarians and vegans respectively than for regular meat eaters
Quantity and quality of protein
According to the most recent recommendations of the Health Council of the Netherlands, we need 0.83 grams of protein per kilogram of body weight per day. For example, for a 70 kg adult, 58 grams per day would be sufficient. However, with proteins it is not only about quantity but also about quality.

The human body is constantly breaking down and building new cells. Specific building blocks are needed for this: the amino acids from which proteins are built. To be used as building material, it is important that these amino acids are present in the right proportions. Especially the essential amino acids are, as the name implies, essential, because the human body cannot make them itself.

Animal products have an amino acid composition so similar to ours that they already have the right profile to build new tissue from. Getting the right proportions of amino acids with a plant-based diet is a bit trickier. This is why the internet is full of advice to vegans to eat grains with legumes. Rice and wheat, for example, have too little lysine, and beans have too little methionine and cysteine to provide full-fledged protein on their own. By regularly alternating them over different meals, if necessary, you can still obtain a good ratio of amino acids.

Proteins from plants are also more difficult to digest than meat. This is partly because their matrix is more difficult to break down due to the presence of fibres such as cellulose. On the other hand, proteins from plants that have been sufficiently broken down by processing, such as soy protein isolate and wheat gluten, are easily absorbed.

Nutrition scientists call the protein quality that includes both amino acid composition and digestibility the Protein Digestibility Corrected Amino Acid Score (PDCAAS). Thus, this PDCAAS is usually lower for proteins from plants than for proteins from animal products. The Food and Agriculture Organization (FAO) recently recommended replacing the PDCAAS with the Digestible Indispensable Amino Acid Score (DIAAS). This also includes, for example, ‘antinutrients’ that make absorption more difficult. With the new DIAAS score, the total protein quality of plants drops a bit in the official statistics. Because of these differences in protein quality, the Health Council of the Netherlands recommends a protein intake that is 1.2- and 1.3-times higher for vegetarians and vegans respectively than for regular meat eaters.

An example of a micronutrient that people can only get from animal products is vitamin B12
The bacterial vitamin
In addition to protein, animal products provide higher and/or more absorbable varieties of certain vitamins and minerals. One example of a micronutrient that humans can only get from animal products is vitamin B12. This substance, essential for the synthesis of DNA and for the metabolism, is made exclusively by bacteria that live mainly in the soil and on plants. The microbiome in the human colon is capable of making a small amount of B12, but because of the structure of our digestive system, we are then unable to absorb it. In addition, our own food is quite clean, and so the colony of B12 bacteria on our food is also small. Fortunately, cows (and other grazers) do not wash their grass, so bacteria ingested with grass take up permanent residence in the bovine microbiome. Grazers' intestines can actually handle B12, so the B12 these bacteria produce ends up in the muscle meat and in the milk. There seem to be few real plant sources of B12: most analogues in certain seaweeds are unusable by humans.

Very promising are duckweed and a number of specific types of algae, in which the B12 again seems to come from bacteria and is absorbable. For the vast majority of people, it is of course much easier to just eat a steak now and then, or - for those who don't want to - to pop a vitamin pill.

Besides vitamin B12, there are other micronutrients that are more abundant and/or more absorbable in animal products. For interested readers, nutritionist Stephan Peters wrote in May 2020 about the effects that the government's planned protein transition could have on public health. He provides more information on protein, protein quality and micronutrients, and adds points of interest for vegans and others who are going to eat predominantly plant-based foods. In addition to Peters, other experts recommend caution when making a complete switch to a plant-based diet because of possible negative health effects.

Instead of having to puzzle with plants ourselves, the food industry is there for us to make things a little easier. A variety of plant-based meat substitutes have been on the shelves for decades, and the range of products is constantly expanding. Moreover, research into improvements and new techniques is obviously moving forward. Want to know whether all these products replace meat perfectly? Read on a little further.

Not every meat substitute is vegan-friendly
The alternatives
Innovations can facilitate both the nutritional and taste aspects of the protein transition, and some are already available. Following on from plant proteins, there are several types of algae that provide high quality protein. Also, with the emergence of cultured meat, we can eventually eat animal protein without having to slaughter animals. In addition, insects have a high protein quality. Mealworms are now approved as human food by the European Food Safety Authority (EFSA). And last but not least, there are all kinds of biotechnological developments with which proteins and other nutrients can be cultured in bioreactors, with the help of bacteria and fungi.

How do plant-based meat replacements and these other products and techniques compare with animal products in terms of health, sustainability, and deliciousness? This question will have crossed your mind by now, so I will try to answer it below based on the available literature.

Mostly for fun, in other words. Marketopportunity: additional vitamin pills in the package of the vegetable burger
Meat substitutes from plants and fungi
When Laura was a little girl, she decided, to the horror of her mother who prepared her meals every day, to become a vegetarian. Almost two decades ago, the meat substitutes available were unfortunately not what they are today. Except for the Maaslander cheese schnitzels (actually just breaded cheese that you could fry, retired from the retail channels since 2016), eating meat substitues felt a bit like eating cardboard. Because I was still missing something (some iron and B12, but mostly bacon), I stopped eating alt meat after a few years and started eating meat again occasionally. Fortunately, the industry has progressed in the mean time, and meat substitutes have improved considerably in terms of taste and texture.

The meat substitutes that we can buy in the supermarket consist of several main ingredients. In addition to legumes such as soy, different types of peas and lupine, grains such as barley, oats and wheat are used. Although fungi are not plants, mycoproteins such as Quorn are also often included in this group. For convenience, I'll do the same.

Not every meat substitute is vegan-friendly: many producers use dairy for flavour and nutritional value (like Valess) and/or egg as a binding agent. Moreover, to make tasty meat replacements from these kinds of raw materials often requires a hefty amount of processing and a pile of additional ingredients.

The climate effects vary by product type. According to this study, the production of Quorn involves the emission of 3 kg of CO2 equivalents per kg, and other comparable mycoproteins emit 6 kg. That's comparable to the emissions of a standard supermarket chicken (2 to 7 kg CO2-eq/kg, depending on the species, the diet and, of course, the calculation method), but still way better than the emissions related to beef.

Other researchers calculated the environmental impact of meat alternatives and concluded that the outcome is highly dependent on the method of calculation. For those who read the previous article in this series, this will come as no surprise.

Regardless of the calculation method, mycoproteins - together with cultured meat - have the highest climate impact of the meat alternatives. This is mainly due to the high energy consumption of the growth reactors and the required post-processing. In the linked study, when calculated with energy density rather than kilograms, insects, soy, and real chicken (fed with locally grown feed but probably of a fast-growing type) had the least environmental impact. Dairy and wheat meat substitutes were in between with a medium impact. All in all, soy-based meat substitutes in particular appear to produce substantially fewer emissions than animal products, despite the heavy processing required. In any case, the plant and fungi-meat replacements with other raw materials perform better than beef and pork.

In addition to the emission issue, raw materials are needed to make these meat replacements. Obviously, land is needed for that. The question you should be asking is whether, in terms of land use to nutrient ratio, it wouldn't be a lot more effective to just eat the legumes grown for this purpose directly. The answer is an obvious yes. Processing costs more transport, machinery, and energy.

Moreover, the nutrients in the various types of meat replacements are not all that great. According to research, meat substitutes have a healthy image. According to other research, this is not entirely justified: many meat substitutes contain (too) much salt and/or fat, and enrichment with sufficient vitamin B12 and iron rarely occurs.

On the other hand, meat substitutes are becoming increasingly tasty, and are probably intended primarily to mimic the meat experience. So, it's mainly for fun. Gap in the market: additional vitamin pills in the packaging of the vegetable burger.

Algae are packed with other vitamins, minerals and fatty acids, including some that are especially important for vegetarians and vegans such as iron and provitamin A. They also contain vitamin B12, but in these species mainly in the form of pseudo-vitamins, which the human body can't do much with
Like plants, algae get their energy from sunlight; these ancient organisms engage in photosynthesis. There are several classes in the algae world. The nori we make our sushi with is a red seaweed, as is dulse, the seaweed that was a trend a few years ago because it was said to taste like bacon. Hipster superfood Chlorella is a single-celled green seaweed, and the wakame seaweed salad you can find at the supermarket may look green but is actually a brown seaweed. The classification is not so much about the colour of the algae, but about when and how the species got their chloroplasts in evolution.

Chlorella is often mentioned in the same breath as the other ‘superfood’ spirulina (Arthrospira in scientific language). Spirulina is also popularly called blue-green algae, but it is actually a cyanobacteria. Fun fact: chloroplasts in algae (from which plants later evolved) probably came about because the cells of ancestors of algae 'ate' cyanobacteria. This evolution also provided a nice word for Scrabble: we now call it the endosymbiotic theory.

Because there are so many different types of algae (and fake algae), not much can be said about the nutritional value of the group as a whole. Specifically, as an alternative protein, companies such as Phycom and the Bühler Group are primarily betting on Chlorella and spirulina. These variants both have a high protein content of about 50% of dry mass. Moreover, they are complete proteins, meaning all essential amino acids are present. Vitamin B12 is also present, but in these species, it is mainly in the form of pseudo-vitamins, which the human body cannot use very well.

However, algae are packed with other vitamins, minerals, and fatty acids, including some that are extra important for vegetarians and vegans - such as iron and provitamin A.

Even newspaper headlines agree that algae are the food of the future, and Damhert Nutrition already has an algae burger on its shelves. The company does forget to mention that the B12 from algae is not easily absorbed, so don't forget your vitamin pill. Oh, and the protein actually comes mainly from wheat gluten: the burger contains 3.7% spirulina powder. According to Meneer Wateetons (a Dutch food writer), it tastes like a vegetable burger. The green powder itself can also be bought in the supermarket. It does not taste like a (vegetable) burger, but apparently is very healthy.

The cultivation of algae is very easy, fast, can be done anywhere, and requires little space. It does not provide competition for arable farming. In addition, algae engage in photosynthesis. They therefore live largely on free sunlight and require few nutrients. Moreover, algae cultivation offers opportunities for CO2 capture.

However, the proteins of algae are contained in the cell walls. The human body cannot use them without first destroying the cells. Because destroying the cells still requires a great deal of energy and/or the use of specialised chemicals, sustainability is somewhat disappointing in practice. Spirulina is the big exception here. Unlike real algae, the cyanobacteria have no cellulose in the cell walls, which makes it much easier for us to absorb the proteins. So apart from the vitamin B12, spirulina in particular seems like a great option for replacing meat sustainably.

To make the green gold even more cool: it is literally astronaut food. NASA was already investigating the potential of micro-algae in the 1980s because they are so nutritious and easy to grow in space. However, a problem arises: spirulina goes down pretty well in your smoothie, but from a sensory perspective it looks nothing like meat. The bacon algae dulse (Palmaria palmata) apparently does, but that is a real algae whose cell walls the human body is unable to break down properly. For a tasty and nutritious fake steak, we will have to look a little further.

Several supermarkets already had insect products on their shelves, both jars of whole insects and processed into products such as flour, breakfast cereals, burgers and schnitzels. However, demand was too low, causing supermarkets to withdraw
Modern Westerners may be a little creeped out by the idea, but our prehistoric ancestors were already eating insects. This did not stop with the emergence of Homo sapiens, as eating insects is still normal in certain cultures today. Insects are an important part of the diet in 130 countries, especially in Africa and South America. Species to which humans are genetically most similar - chimpanzees and bonobos - also enjoy a termite here and an ant there. Not a bad choice in itself: most insects have a high protein and fat content, and primates are programmed to love calories.

From a nutritional point of view, insects seem an ideal solution to replace conventional meat: insects have a similar protein quality, but also contain high amounts of vitamins (including B12), minerals and fibre. Although it depends on the calculation method, there is research showing that eating insects may even be a healthier way to get the nutrients we normally ingest through meat. On top of that, the environmental impact of growing insects is the lowest of all meat alternatives, along with soy meat replacements. The critters are incredibly efficient at converting nutrients into biomass. In addition, they eat just about anything, so insects can grow on our agricultural waste. Moreover, they do not require much space. Because of this combination, growing insects does not compete with arable farming - as long as the supply of waste lasts.

It all sounds very nice, but unfortunately consumers don't seem to be waiting for it. Several supermarkets already had insect products on their shelves, both whole insects and processed in products such as flour, breakfast cereals, burgers, and schnitzels. However, demand was too low, so supermarkets pulled back. At this point in time, only Jumbo sells jars of buffalo worms. Apparently, it doesn't matter much if the insects are processed into something unrecognizable. The average Western person finds the idea of eating insects ‘scary’ enough not to do it.

On top of that, insects are also just another group of animals. Although current knowledge suggests that insects are unlikely to experience pain, most vegans also abstain from eating honey because they reject any exploitation of animals. Both vegans and (some) vegetarians will probably not be okay with insect burgers and thus already fall outside the target group.

Would-be entomophages can find insects online, for example at De Krekerij or Delibugs. For a successful re-entry onto the supermarketshelves, an extraordinary marketing campaign would seem necessary.

According to research, the primary obstacle is indeed the social change that needs to take place in order to use insects as an alternative protein. So, science agrees with the Dutch saying ‘what a farmer doesn't know, he doesn’t eat’.

Cultured meat has fewer micronutrients due to its ‘unnatural’ growth method. Because the mass in a petri dish has no gastrointestinal tract, it therefore has no associated microbiome and vitamin B12 factory hanging on it
Cultured meat
According to ABN AMRO, it won't be long before we can all enjoy a piece of cultured meat. As with insects, consumer acceptance of cultured meat seems to play a major role: 35% will not try it because it is 'unnatural'. The fact that the taste and texture will hopefully be 'just like the real thing' is apparently not enough for this group to counteract the feeling of unnaturalness.
On the other hand, 41% of consumers are positive (especially if cultured meat becomes affordable) while 23% are hesitant.

The technology is attracting the attention of investors: the Dutch companies Meatable and Mosa Meat have recently raised millions to expand development and production.

The unavoidable use in the growth medium of calf serum, extracted from foetuses, was previously objected to as making cultured meat unethical. Meanwhile, many companies, including Meatable, have managed to develop a plant-based alternative. In addition, current techniques are useful for cultivating muscle cells, but the actual structure and texture of, for example, a ribeye is so complex that it is difficult to cultivate such pieces of meat in a factory.

The Israeli company Aleph Farms may have found a solution to this by combining cultured meat technology with 3D bioprinting. This is still in its infancy, though.

The first cultured meat to be launched commercially will probably be in the form of hamburgers or chicken nuggets, already available in Singapore. According to research, sausages in particular are easy to reproduce. Because also for the production of conventional (‘real meat’) sausages muscle tissue is very finely ground, sausages and burgers are the easiest forms to imitate in terms of texture.

In addition to taste and texture, cultured meat has other advantages over conventional meat. It requires no land, and in a petri dish (or reactor), the muscle cells handle nutrients much more efficiently than in a cow. It is cleaner because the mass in the petri dish has no gastrointestinal system. It is ‘real’ meat without the need for animals to suffer, especially now that there is a solution to calf serum. As a result, the protein quality of cultured meat is equal to that of conventional meat.

Experts are still not entirely convinced on the sustainability of cultured meat. This is because cultivation involves high energy consumption. According to this 2011 study, the amount of energy required for cultured meat is comparable to pork, but in terms of land and water use and GHG emissions, cultured meat does significantly better than all other types of meat. In a newer study (2019), the various impacts of the different greenhouse gases were actually considered and projected mathematically in a number of ways up to 1,000 years into the future. According to the study, there are scenarios in which cultured meat does more harm than conventional beef in the long run, and the environmental gains to be made from it depend heavily on where we get the energy from for the culture. If we actually succeed in making the energy supply more sustainable and electrified, it is likely that this technique will prove to be cleaner than the production of conventional meat.

On the other hand, as mentioned above, a large proportion of consumers still have doubts or even negative attitudes about the unnaturalness of cultured meat. In addition, cultured meat contains fewer micronutrients due to its ‘unnatural’ growth method. Because the mass in a petri dish has no gastrointestinal tract, it therefore has no associated microbiome and vitamin B12 factory attached to it. Many other micronutrients enter meat primarily through feed. To give cultured meat the same nutritional value as conventional meat, therefore, it will have to be doctored even more. All in all, cultured meat - like many plant-based meat substitutes - will likely be primarily a substitute for taste experience and mouthfeel, perhaps also for protein but less so for much-needed vitamins.

Is fermentation technology the solution?
All in all, it seems that modern humanity has not yet found a perfect solution to replace meat. Cultured meat and industrially made meat imitations from plants and fungi do okay as substitutes for taste and texture, but do not offer great nutritional value. Moreover, for both, the question must be asked as to how environmentally friendly they really are. After all, cultured meat and mycoproteins take a lot of energy and meat substitutes from plants take a lot of land and processing.

Insects and algae are excellent substitutes from a nutritional point of view and are environmentally friendly. However, taste, texture and emotional acceptance by consumers remain major obstacles. Fermentation technology may offer a solution to this. Micro-organisms can be used in their entirety as a good source of protein and can also be used to produce specific substances. This will probably make it possible in the future to produce 'animal' proteins without animals. This has already been achieved with fake mayonnaise; moreover, researchers and companies all over the world are working on the development of cow-free real dairy products.

According to a report by the Good Food Institute (GFI), of the $1.5 billion pumped into meat substitutes in the first half of 2020, one-third went specifically to fermentation techniques. A very promising technology as it involves rapid production with little land use, low nutrient inputs, and endless applications, especially thanks to new developments in genetic engineering such as CRISPR-cas9.

Due to the growing interest in and broad potential of fermentation technology, the next article in this series will look at it in detail.