Andrew Knight

Importance
In recent decades there has been an expansion in the quantity and quality of scientific findings and guidelines on different health topics to promote individual and public health status. Reports also indicate that there has been a simultaneous increase in the financial burden of disease, including trillions spent on healthcare resources by governments worldwide (predominantly in developing countries) to address health concerns. At the same time, personal health behavior is well-known as efficient and cost-free, holding four times the potential to prevent early death compared to health care. Despite this knowledge, data show that the increasing prevalence of unhealthy lifestyles and the associated chronic diseases, especially in Western societies, still need to be controlled. This circumstance exemplifies today‘s global health dilemma, which alarms the inadequacy of ongoing efforts to address the existing health concerns worldwide.

Setting, insights, and observations
Three international, multidisciplinary, and inter-university events (two scientific conferences and one tertiary education symposium) were held in Austria (Innsbruck) between 2020 and 2022 to discourse, discuss, and debate these concerns. Two hundred eighty-four experts from 76 universities, organizations, and stakeholders spanning 31 nations and five continents participated in this international research and knowledge exchange to address today's global health dilemma. The latest scientific findings were discussed to develop practical strategies for improving lifestyle behavior and focus on the dual “Healthy Eating & Active Living” approach as a minimum recommendation for sustainable lifelong health and care. The expert panel debated crucial research priorities and future policies, identified gaps and untapped potential in basic health approaches that have been grossly neglected, and approved the evidence-based 101 consensus statements presented.

Conclusions and relevance
These endeavors aim to develop novel and effective interventions that address the needs of individuals and communities and promote optimal health status.

Highlights
• To address the global health dilemma of increasing non-communicable (chronic) diseases despite growing advances in health science and healthcare budgets, it is the consensus of the panel of experts that the power of Lifestyle Medicine has the potential to significantly contribute to the “Prevention First” appeal. The dual approach to sustainable and lifelong health—“Healthy Eating & Active Living”—is the minimum recommendation inclusive of every individual for better public health.

• To maximize health benefits for all, the permanent linkage of “Healthy Eating” is, at best, whole food plant-predominant, preferably vegetarian/vegan, and “Active Living” is, at best, daily and outdoors/in nature.

• This consensus statement aligns with the current trend towards de-medicalized and more holistic, personalized approaches to health and well-being, focusing on sustainable preventative policies.

Global greenhouse gas reduction targets are applied to many sectors in many countries, as part of the Nationally Determined Contributions mandated within the Paris Agreement (climate). However, industrialized animal farming is typically missed out or deprioritized. This is despite suggestions that excluding this sector would automatically result in global failure to meet 1.5 °C and potentially even 2 °C maximum temperature rise targets, even if fossil fuel use were to immediately cease. To foster further discussion and assessments about the need for such targets in relation to industrialized animal farming, this study collated and analyzed recent studies on the impacts of industrialized animal farming on the environment. Of the 579 items initially retrieved, 47 studies were shortlisted. Over three quarters (
= 37, 79%) of the shortlisted studies were unequivocal concerning the significant negative impact industrialized animal farming has had, and continues to have, on climate change and broader environmental concerns-between 12 and 20% of
greenhouse gases, and 50%, 32%, and 76% of all
eutrophication, soil acidification, and land use, respectively. This all creates immense contributions to biodiversity loss, which itself further aggravates climate change. The remaining studies did
assert that industrialized animal farming had an
significant impact; however, their findings complicated the picture in one way or another (e.g., suggesting suboptimal measuring methods) or they had flawed methodologies. As a matter of urgency, the present paper recommends that targets for significant reductions in levels of animal production and consumption should be incorporated into discussions and policies for tackling the climate crisis, such as at COP30.

There is increasing awareness about the adverse environmental and ‘food’ animal welfare impacts associated with the production of meat-based pet food. However, little is known about cat guardians’ acceptance of more sustainable food choices for the global population of approximately 476 million pet cats. By surveying 1380 cat guardians, this study explored feeding patterns used by guardians, determinants of their cat food choices, and their acceptance levels of more sustainable cat food alternatives. The sources of information used by cat guardians to obtain information about the cat diets they chose were also investigated. Key results included: (1) 51% (620/1211) of cat guardians currently feeding meat-based cat food (raw or conventional) considered at least one or more sustainable alternatives to be acceptable, with cultivated meat-based cat food being the most popular alternative, followed by nutritionally sound vegan cat food; (2) the top five characteristics alternative diets needed to offer to be considered viable were good health outcomes, nutritional soundness, palatability, quality, and environmental sustainability; (3) diet types consumed by cat guardians and their cats were strongly associated; and (4) labels/packaging and veterinarians were the information sources most used, although veterinary staff may have been less trusted as reliable sources of dietary advice by guardians feeding unconventional diets. It should be noted that, due to the reliance on convenience sampling and the overrepresentation of respondents from the UK, of female guardians, of respondents with higher education and of vegan guardians, the reported relative frequencies of subgroups were not fully representative of the global cat guardian population. Association estimates were based on regression analyses to minimize any resultant bias effects.

Approximately 1.8 billion chicks are hatched worldwide in commercial hatcheries every month. A typical commercial hatchery is a high-speed and stressful environment. Not only is chick welfare impacted while at the hatchery, but also chickens’ early life experiences can have long-lasting impacts on their welfare once they leave the hatcheries. Additionally, chick embryos may have the capacity to experience stress and pain. This study systematically reviewed recent scientific studies exploring the starting point for the capacity to suffer in chicks and chick embryos. It found that the capacity to suffer (i.e., to experience pain, distress, or other prolonged negative welfare states) may commence by embryonic day 18—three days before hatching—and likely earlier. Based on this, serious and widespread welfare problems may exist for the 1.8 billion chicks hatched in hatcheries globally every month.

Interest in more sustainable diets for the global population of 528 million companion dogs is steadily increasing, encompassing nutritionally sound cultivated meat, vegan, and microbial protein-based dog foods. Factors driving these alternative dog foods include lower impacts on the environment, fewer welfare problems related to intensively farmed animals and wild-caught fish, and potentially superior canine health outcomes, relative to conventional meat-based dog food. Through a questionnaire with 2639 responses, this study aimed to gain insights into dog guardians’ current feeding patterns and dog food purchasing determinants, acceptance of more sustainable dog diets, and sources of information used for decisions about dog diets. Key results included that 84% (2188/2596) of respondents currently fed either conventional or raw meat-based dog food. More than 43% (936/2169) of this group of respondents who answered found at least one of the more sustainable alternative dog foods acceptable, with purchases of these alternatives hinging most commonly upon the nutritional soundness of the products. Cultivated meat-based dog food was the most popular alternative (selected by 24%, 529/2169), followed by vegetarian (17%, 359/2169), insect-based (16%, 336/2169), and vegan (13%, 290/2169) dog food. The top three information sources used to make decisions regarding dog diets were labels/packaging (selected by 42% of all respondents, 1080/2596), scientific articles/books (38%, 989/2596), and business webpages (35%, 900/2596). Numerous human and dog demographic variables had impacts on current diets, acceptance of alternative diets, and information sources used. Notably, human diet and dog diet were the factors most commonly associated with current and potential purchasing decisions, as well as with information sources used. For instance, greater reductions by guardians in the consumption of animals were associated with greater acceptance of more sustainable dog diets. It should be noted that, due to the reliance on convenience sampling and the overrepresentation of respondents from the UK, of female guardians, of respondents with higher education, and of vegan guardians, the reported relative frequencies of subgroups were not fully representative of the global dog guardian population. Association estimates were based on regression analyses to minimize any resultant bias effects.

Rapid climate change is one of humanity’s most pressing global challenges, and we must urgently address unsustainable practices in all sectors to mitigate its most devastating effects. The pet food sector is a large and growing global industry that feeds about one billion dogs and cats. Moreover, its production is closely linked to the livestock sector, to which at least 25% of all anthropogenic greenhouse gas (GHG) emissions to date are attributable, and probably substantially more. Globally, dogs and cats consume 9% of livestock animals. In the US, this rises to 20%. This review collates and analyses studies on the environmental impacts of pet food, and recommends mitigation strategies. All reviewed studies agree that pet food is associated with at least non-negligible environmental impacts that must be accounted for and addressed: in the US, 25–30% of the environmental impacts of animal production have been attributed to companion animal diets. Studies have estimated a wide range of environmental “paw prints” for dog and cat diets; in some cases, the environmental impacts of some canine diets compare to or exceed those of human diets. Within pet food, ingredient selection is the most important factor. The most effective measure we can currently take to mitigate these impacts is to transition to non animal-based (vegan) pet food, where this has been formulated to be nutritionally sound. Such a transition could achieve very significant GHG and land use savings. In wealthy nations with high rates of companion animal guardianship, the benefits of this transition are demonstrably equivalent to one quarter to one third of the environmental benefits achievable through human dietary change. A transition to nutritionally sound vegan pet food represents a significant extant climate change mitigation strategy which warrants immediate implementation.

Pigs are the fourth most commonly slaughtered species used for food, after fish, chickens, and ducks (1). In 2022, an estimated 1.49 billion pigs were slaughtered globally. Within the UK for example, more than 11.4 million pigs, sows, and boars (hereafter, pigs) were slaughtered in UK slaughterhouses in 2022 (2). By late 2024 this equated to nearly a million pigs monthly, or nearly a quarter of a million weekly (3). In 2023, there were 84 slaughterhouses accepting pigs in the UK, with 10 of these specializing in pigs insofar as 95% or more of the animals slaughtered were pigs (4).

Stunning aims to render pigs unconscious before being killed and processed. The vast majority (88%) of pigs in England and Wales are stunned and killed using high concentration CO2, with electrical stunning being used for most of the remaining 12% (5). Since 2003, there have been calls for the phasing out of high concentration CO2 (6, 7), which have been reiterated more recently (8).

In the following, we provide a brief review of the animal welfare concerns associated with CO2 stunning. These are then compared with the welfare concerns associated with alternative stunning methods. Welfare concerns arising from preslaughter handling and restraint for each method are also considered. This review does not cover religious slaughter because: 1) Judaism and Islam do not permit the consumption of pig flesh (9), and 2) religious (e.g., Shechita and Halal) slaughter doctrines normally proscribe methods that both stun and kill animals, which may occur with CO2 stunning, as is required when CO2 is used within the UK, for example (10).

Humanity is facing an important existential threat—irreversible climate change caused by human activity. Until recently, most of the proposals to address climate change have downplayed or ignored the adverse impact of food systems, especially intensive animal agriculture. This is in spite of the fact that up to a third of global greenhouse gas production to date can be attributed to animal agriculture. Recent developments at COP28 have signaled that the tide is turning, however, and that food systems are becoming part of global discussions on climate change solutions. The pressing nature of irreversible climate change requires rethinking our food systems. To solve the climate change crisis, we propose transitioning to a predominantly plant-based diet, and phasing out intensive animal agriculture as diets shift, without increasing pastoral farming. We suggest that such transformations in global food systems can be accomplished largely through education and large-scale public information campaigns, removal of subsidies, taxation to account for externalized costs of animal agriculture, improved labelling of products, and various investment/divestment drivers. Better metrics and industry benchmarks involving food and agriculture-specific performance indicators that reflect food system sustainability will be important. Increased global awareness of these issues and a change in mindset (which will drive political will) also are needed. Our current trajectory is untenable, and we must begin to turn the ship now towards sustainable food systems and diets.

Environmental impacts attributable to livestock production are proportionate to consumption levels. To compare the consumption of livestock animals by dogs, cats and people, the dietary energy needs of each group were calculated for the US and globally. US pet food ingredients (2020), and environmental impact data for plant- and animal-based ingredients were also analysed. A worldwide transition to nutritionally sound vegan diets within each group could end the slaughter of the following numbers of terrestrial livestock animals annually (billions): dogs – 6.0, cats – 0.9 and humans – 71.3, along with billions of aquatic animals. Land freed up would exceed the areas of: dogs – Saudi Arabia or Mexico, cats – Japan/Germany and humans – Russia (the world’s largest country), plus India. Freshwater volumes spared would exceed all renewable freshwater within: dogs – Denmark, cats – Jordan and humans – Cuba. Greenhouse gases (GHGs) eliminated would exceed all GHG emissions from: dogs – South Africa or the UK, cats – Israel or New Zealand and humans – India or the entire EU. Food energy savings could feed human populations greater than those of: dogs – the entire EU, cats – France or the UK and humans – two-thirds of the Earth’s population.