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Abstract
Alternative meat is designed to address concerns about the impact of traditional meat on the environment, animal welfare, foodborne illnesses and human health. The availability, market share and variety of substitute meat products have exploded in recent years. This review will discuss the different types of alternative meat available, the benefits and challenges associated with their production as well as the regulatory and consumer acceptance issues that must be addressed to ensure their success. Cultivated or lab-grown meat is discussed as a separate category from all plant-based meat products because its nutritional composition is much closer to traditional meat. There is limited information about specific alternative meat products in the diets of children under five and the possible role meat substitutes can play in vegetarian and omnivorous diets. When planning a diet for a young child, parents and nutritionists will need to consider the consumption of each alternative meat product in the context of the child’s age, nutritional requirements, health status and the composition of their overall diet.
- dietary patterns
- nutritional treatment
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Introduction
Animal agriculture is a major contributor to carbon emissions, deforestation, water pollution and habitat destruction. Moreover, the meat industry is often criticised for animal welfare concerns, including cruelty and inhumane treatment of animals. To address these issues, there has been a surge in the development of meat alternatives. Alternative meat aims to mimic the texture, flavour and nutritional profile of real meat. Alternative meat has become increasingly popular as a healthier and more sustainable alternative to traditional meat, especially among adult vegans, vegetarians and flexitarians. There is a wide variety of consumer choices currently available both in terms of the type of meat substitute and the ingredients used to make the meat substitute. Depending on the country, a variety of commercially available or in-development substitutes for beef, chicken, pork and seafood exist. The types of ingredients used vary widely from plants, mycoproteins and algae to insects as well as to cultured meat from single cells. The food companies active in the alternative meat business range from small start-ups to large conventional food multinationals including PepsiCo, Nestle, Kraft/Heinz, and even traditional meat companies such as Tyson and Hormel.1
There are important nutritional differences among all these products and between the types of meat that they are designed to replace. The holy grail for the alternative meat industry is to completely replace traditional meat in the human diet. The intermediate aim is to partially replace traditional meat in the diet of flexitarians.2 There is no regulatory framework that defines the composition or the naming of meat substitute products.3
Types of alternative meat
Plant-based products
Plant-based meat or protein substitutes are not a new concept. However, they have recently gained significant attention and investment from the food industry driven by consumer concerns about the environmental sustainability and the ethics of animal-derived foods. The manufacture of plant-based meat involves the selection of ingredients, processing and formulation. The primary ingredients used in plant-based meat are plant proteins, such as soy, wheat, mushrooms, lentils and pea proteins.4 These are combined with fats, carbohydrates and flavourings, to create a product that closely mimics the texture and flavour of traditional meat.5 One of the biggest challenges in developing plant-based meat is replicating the texture of traditional meat.6 Another important challenge is its nutritional profile.7–11 Traditional meat is an important source of protein, iron and vitamin B12, especially for young children. Therefore, many manufacturers of plant-based meat fortify their products with nutrients. One unique plant-based approach involves adding an animal-like heme protein (eg, leghemoglobin) produced by genetically modified yeast to the mixture to improve the texture, taste and nutritional value of the final product.12 Homemade and organic plant-based products are typically minimally processed, while commercially produced versions are typically heavily processed and often contain additives and emulsifiers.
Mycoprotein-based products
Mycoproteins are proteins made from a type of filamentous fungi and used to create meat-like products. Mycoprotein-based products are created by fermenting fungi with sugar, such as glucose or lactose and nitrogen-containing media.13 The resulting product is a protein-rich mass that can be used to create meat-like products with a fibrous texture and a slightly nutty flavour profile, which makes them a good substitute for ground meat in dishes like chili and spaghetti sauce.
Insect-based products
Insect-based products are an unconventional addition to the meat substitute market.14 The most popular insects used to create meat alternatives are crickets, mealworms and black soldier flies. Insects require little water and food to survive compared with traditional livestock and are high in protein, vitamins and minerals. These products may be locally produced at low cost.15 The biggest challenge with insect-based products is consumer acceptance. Many people are hesitant to eat insects due to cultural and psychological factors. Edible insects are widely consumed in subtropical and tropical regions, but not in the USA and Europe.16 Another key challenge is ensuring the safety of insect-based products. Insects can carry bacteria and other pathogens potentially harmful to humans. Special precautions must be taken to ensure that insects are not grown on contaminated food and human waste.17
Cultured or cell-based products
Typically, the production of cultured meat involves five steps (figure 1). Step 1 involves cell line selection and cell banking from an animal (including cows, pigs, chickens or fish). Step 2 is the proliferation stage where the cells are grown in suspension in a nutrient-rich environment in a bioreactor. Step 3 involves the differentiation and maturation of the cells into the desired tissue including muscle, fat and connective tissue.18 In some cases, cultured meat manufacturers use a scaffold, made from plant-based fibres or hydrogels, to guide the growth and arrangement of the cells.19 Step 4 is the harvest step and Step 5 is the packaging. In the USA, Steps 1–3 are regulated by the Food and Drug Agency. Steps 4 and 5 are regulated by the US Department of Agriculture. In Singapore, the approval process is streamlined and is entirely handled by the Singapore Food Authority. Additional regulatory frameworks are used and are under development by other countries and by the WHO.
Production steps typically used in the manufacture of cultured meat.
The main challenges of cultured meat are how to make the scale-up process cost-effective, energy-efficient and sustainable.20 A recent analysis tried to understand, model and predict the environmental impact and financial considerations of cultured meat. While laying out the assumptions for the model, they identified critical aspects of cultured meat production that need to be improved.21 These areas are listed here to illustrate where much of the ongoing research in this field is focused: (1) facilities producing 10 000 metric tons of cultivated meat/year; (2) food-grade culture media made without animal products and hormones to enable cells to grow at high density and with cell doubling time of ~30 hours; (3) production cultivators with 10 000 L capacity; (4) differentiation to take place over a 10-day period in 2000 L perfusion cultivators; (5) overall continuous closed process without the use of antibiotics with minimum three harvests/run.
Progress is indeed being made towards these goals. Food-grade culture media,22 the serum-free culture of meat23 and an artificial version of fetal bovine serum have all been developed.24 Cultured chicken products are currently on the market in Singapore.25 In the USA, cultured chicken has been approved for consumption by both the Food and Drug Agency and United States Department of Agriculture.26
Health considerations of a vegetarian diet for young children
In adults, a vegetarian diet has been associated with a lower risk of chronic diseases and conditions such as high blood pressure,27 28 coronary heart disease and type 2 diabetes,29 weight control,30 and improved gut health (including effects on the diversity of the microbiome and intestinal inflammation).31 The American Academy of Pediatrics32 and the Academy of Nutrition and Dietetics acknowledge that a well-planned vegetarian diet can meet the nutritional needs of young children.33 However, the emphasis is on ‘well planned’, as children on vegetarian and vegan diets are at increased risk of deficiency in iron, B12 and calcium, and may have lower protein quality leading to amino acid deficits. Additionally, the health benefits of entirely plant-based diets in children under 5 years of age are less clear than they are in adults (see accompanying review article on vegetarian diets for children).34 A recent systematic review concluded that, to date, there is no data demonstrating any health benefits of vegetarian diets in children aged 6 months to 2–3 years.35
Health effects of alternative meat for young children
As shown in table 1, there are multiple differences between the alternative meat products currently available and the traditional meat they are trying to replace. To date, there is no data available on health effects of specific types of alternative meat in young children and, given that most children will consume alternative meats as part of an omnivorous diet and that randomised trials in children are unlikely to be commissioned, evidence on health effects would likely be based on cross-sectional associations comparing high and low consumers. Specifically, the alternative meats are manufactured and typically contain higher levels of food additives which, although approved as safe, might have previously unknown harmful effects.36 37 Meat alternatives typically offer the advantage of being lower in calories and fat. Several studies from healthy adults have shown that replacing traditional meat with plant-based meat products can have a beneficial impact on markers of cardiac health and inflammation while having no detrimental effect on athletic performance,38 39 but no such studies are available for children of any age on any cultured meat products.
Nutritional content of alternative meat products marketed in the USA in 2022
Cultured meat
While the potential health benefits of cultured meat are promising, there are also concerns about the safety of these products, particularly for young children. The nutritional profile of cultured meat is generally similar to the meat from which the original cells are derived. A potential health benefit of cultured meat for children is that it could be manufactured to contain lower amounts of saturated fat and cholesterol and higher amounts of protein than traditional meat.40 Additionally, it could be made to contain higher levels of specific nutrients, such as omega-3 fatty acids and vitamin B12. Cultured meat could also be manufactured in the future free from pathogenic bacteria, such as Escherichia coli and Salmonella, that can often be found in traditional meat products.
One concern is the potential presence of harmful substances, such as antibiotics, hormones and environmental contaminants, in the cell culture medium used to grow the cells. While efforts are being made to develop more sustainable and safe cell culture methods, it is important to ensure that these products are rigorously tested and regulated before they are marketed to consumers.
Conclusions
Over the past 10 years, meat substitutes have gained significant attention as a sustainable and healthier alternative to traditional meat. Types of alternative meat include plant-based, mycoprotein-based, insect-based and cultured or cell-based products. Each type of alternative meat has its own advantages and challenges in terms of texture, flavour, nutritional value and consumer acceptance. In general, alternative meat products made from plants, mycoproteins or insects have a lower environmental impact and a beneficial impact on the health of adults in comparison to animal meat. Alternative meat should be included only as a very small part of the well-balanced diets of young children until more data is available.
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Footnotes
Contributors CC researched the review topic and wrote the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed by Dr Roberta Alessandrini, Queen Mary University of London Centre for Public Health and Policy Charterhouse Square, United Kingdom of Great Britain and Northern Ireland, and Dr Andrew Prentice, MRC Unit The Gambia at LSHTM Nutrition & Planetary Health Atlantic Boulevard, Gambia.