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Introduction: why this Manifesto?

As humans, we are one member of the mammal family. We have been walking around on this beautiful planet for around 200,000 years. Yet in that very limited amount of time we have had an enormous impact– mostly negative. Much of this destructive influence has been directed by what we choose to eat and how we go about securing our meals.

How we humans choose to feed ourselves should in theory nurture human health and support environmental sustainability. The current system of food production and distribution, however, is pushing our planet beyond the limits of what it can actually support.

A mammal-centered diet is not very healthy – either for us or our planet. Empirical studies have demonstrated that reducing or eliminating mammals from our diet can add years to our lives while also improving how we feel throughout those years. Furthermore, by eliminating mammal meat from our diets and embracing this No Mammal Manifesto, we will be contributing to solutions that will ensure that we have an ecologically-sound planet to enjoy in our new-found longer years of good health.

The point of this book is when we have a choice, and most of us do have many choices on the menu, we should choose wisely – for our health, for the health of our planet and for the health of our children in whose hands we leave this planet when we die. Indeed we do need to eat to survive – but as omnivores we can choose to kill or not to kill, and if we kill, we can choose what, when and how.

I hope this book will encourage the reader to think differently about eating mammals, not just because of the mythical bond we share with them (Chapter 4), but because of an understanding that to eat mammals (when we don’t have to) makes no sense from a variety of perspectives – including those related to our health (Chapter 1), the environment (Chapter 2) and the economy (Chapter 3).


A bit of background

The views within this Manifesto did not come to me in a sudden epiphany. I did not suddenly stop eating mammals because someone convinced me not to, nor because I was inspired by a sudden epiphany to change my diet. I evolved into doing so over several years, and the reasons why were complex and motivated by numerous factors, which I have presented in these pages. I wrote this book because I hope to convince you, the reader, to at least take some of my thoughts into consideration and begin (if you are not already doing so) to make conscious and fully informed decisions about the consequences, both personal and planetary, of your dietary decisions.

People whose dietary preferences are out of the mainstream are often asked to explain themselves – unless their restrictions are due to an allergy or a religious dictate. When Muslims turn down pork, no one asks them why they do so. When Hindus turns down a beef burger, they are not asked to explain why. When someone is lactose intolerant, he or she just needs to say “no, thank you” to a glass of milk, and no one will press for a reason.

If you are vegetarian, however, your dinner companions may either act defensive or be genuinely curious and ask you a plethora of questions -- from how long you have been a vegetarian to how “on God’s green earth” you ever do find anything enjoyable to eat.

The usual response I hear from vegetarians is that they wish to reduce animal suffering, benefit the environment, or lead a healthier life. All these ideas ring just as true for those of us who have chosen to exclude mammals from the menu, but the explanation in this instance becomes a bit more complicated.

People often will say, I “don’t eat red meat,” but that misses the point. I did not stop eating mammals because their meat is red. I stopped eating mammals because they are mammals. I did not stop eating meat that is red, I stopped eating meat that was clogging up my red arteries and putting me at an increased risk of heart disease and colorectal cancer. I do not avoid meat that is red. I eschew meat, the industrial production of which is destroying an earth that should always remain green.

I was not always this way. I have lived, worked, traveled, or visited most countries on this precious planet, and in many of them, people do eat a wide variety of things that move and must be caught, captured, or raised in captivity. As part of my travels, I usually joined my hosts in eating whatever they were eating -- pretty much everything from cats and dogs to snakes and even insects.

In the winter of 1980, I found myself trekking through Wyoming’s Wind River Range with a backpack and a pair of old Army cross-country skis. I was 16 years old and taking a winter survival course at the National Outdoor Leadership School. I had two tent mates – a doctor and a psychologist. Both were vegetarians. As a smart-mouthed teenager from the Yukon, who thought it unnatural not to eat meat, I gave both of my tent mates a hard time and teased them relentlessly at every meal.

“But how can you comment on something you know absolutely nothing about,” the doctor finally asked me. “When you don’t know what you are talking about, you are all talk and no bite – just hot air with no substance.”

After a few days of this debate, I finally agreed to stop eating meat for a few months. They both told me I would feel stronger, healthier, and more alive. I doubted them, but I accepted the challenge. The only specific advice they gave me was to read Diet for a Small Planet, the 1971 bestselling book by Frances Moore Lappé that outlined the environmental impacts of meat production. Lappé explained how world hunger was not caused by a lack of food, but rather by ineffective food policies and the industrial production of animal products.

The doctor said I needed to learn about balancing my amino acids. To be a vegetarian, he said, is to be fully aware of one’s body and the effects different foods have on it – combining the right ingredients to get the maximum effect in terms of energy and well-being. If I just ate grains, for example, I would not get enough protein. However, by balancing grains with soy beans, I would have more than enough energy to climb a mountain. I learned this advice to be true years later when I hiked and climbed 300 kilometers around the Annapurna Range in the Himalayas, eating nothing but lentil beans, rice, and vegetables.

Unfortunately my tentmates never had the opportunity to say to me “I told you so.” I lost touch with them, as I continued to explore the world and my place in it, paying particular attention to what and how people eat. Two years later, I had run out of new places to see in North America, and so I set off on a one-way ticket to Africa – and a journey that would take me through fifty countries in five years on a budget of less than $100 a month.

For most of this long journey, I stuck to a vegetarian diet although I did occasionally eat meat when my hosts offered it. When you travel on a shoestring budget, one naturally will rely on the hospitality and generosity of strangers. But when you are hungry, and your host kills a chicken or a goat to honor their invited guest, it would be poor manners to decline. Also, I learned that balancing one’s amino-acids, vitamins, and protein can be challenging when traveling in remote areas of the world, so if given the chance, I did sometimes choose to eat fish or chicken when it was available.

In the beginning…

Before going forward here, let’s back up a bit – actually way back—to review where we humans fit in with the big picture. Life on Earth first emerged about 3.8 billion years ago, initially as single-celled prokaryotic cells, such as bacteria. Multicellular life then evolved over a billion years, and it has only been in the last 570 million years that the kind of life forms that we are familiar with today began to evolve, starting with arthropods and fish.

All animals (that includes us) can be divided into six broad families that range from the simplest (invertebrates) to the most complex (mammals).

Invertebrates are the creatures that we, as mammals, have the least in common with – and therefore, in my view, they are okay to eat. Invertebrates were the first animals to evolve as far back as a billion years ago, and as such, they are characterized by their lack of backbones and internal skeletons, as well as their relatively simple anatomy and behavior. Today, invertebrates account for a whopping 97 percent of all animal species. This widely varied group includes insects, worms, arthropods, sponges, mollusks, fish, and octopuses. Fish evolved from their invertebrate ancestors about 500 million years ago and have dominated the world's oceans, lakes, and rivers ever since.

Vertebrates are a large group that is distinguished by having a backbone or spinal column. This group includes amphibians, reptiles, fish, birds, and mammals.

Let’s look first at amphibians. Amphibians are characterized by their semi-aquatic lifestyles which require them to stay near bodies of water to maintain the moisture of their skins and also lay their eggs and reproduce. Today they are among the most endangered animals on earth.

Reptiles, like amphibians, make up a fairly small percentage of terrestrial animals. This group can be divided into four basic categories: Crocodiles and alligators, turtles and tortoises, snakes, and lizards. Reptiles are characterized by their cold-blooded metabolism fueled by hanging out in the sun. Their scaly skin and their leathery eggs, unlike amphibians, let them survive away from lakes, rivers or streams.

Next are the fish. According to FishBase, a comprehensive online database on fish species, there are 33,100 species of fish in the world.[i] That is more than the combined total of all the other vertebrate species on Earth, including the mammals, amphibians, reptiles, and birds.

New research led by the American Museum of Natural History suggests there are about 18,000 bird species in the world[ii], offering much more for our menu than mere mammals. Descended from dinosaurs, birds are characterized by their coats of feathers, their warm-blooded metabolisms, and their ability to adapt to a wide range of habitats – as seen with the ostriches of Australia and the penguins of Antarctica.

Let’s move on to mammals, among the least diverse animal groups on earth and including only about 5,000 different animals. A myriad of mammal species once roamed the surface of this planet, creating a wonderful tapestry of life that covered every continent. Now, as a result of both the worst species extinction crisis since the demise of the dinosaurs and the rapid expansion of industrialized agriculture, 96 percent of the mammals present on earth today are livestock and the humans who eat them.[iii] Just four percent are the lions, tigers, bears, elephants, giraffes, etc. – and our domesticated cats and dogs.

Mammals are characterized by their hair or fur (all mammals possess either during some stage of their life cycles), the milk they feed their young and their warm-blooded metabolism, which allows them to inhabit a wide range of habitats, ranging from the deserts of North Africa to the arctic tundra in Siberia.

The evolution of mammals has passed through many stages since the first appearance of our ancestors about 300 million years ago. The earliest mammals we know of were the egg-laying animals of the Prototheria subclass, which started out as something close to the platypus. However, we are not concerned with these animals for the purposes of this Manifesto, as there were no humans around then to eat them.

Mammals today range considerably in size from the 30–40 mm (1.2–1.6 in.) bumblebee bat to the 30-meter (98 foot) blue whale. All modern mammals give birth to live young, except for five species of egg-laying mammals (the platypus and four species of echidnas, all indigenous to Australia and New Guinea). However, like all mammals, the female monotremes nurse their young with milk.

Most mammal mothers, obviously including our own human mothers, have a placenta to facilitate the exchange of nutrients and waste between the blood of the fetus and that of the mother. This feature naturally creates a special bond between mother and child that other groups of species do not have. The largest groups of placental mammals are the rodents, bats and Soricomorpha (shrews and their allies). The next three biggest orders, depending on the biological classification used, are Primates (apes and monkeys), Cetartiodactyla (whales and even-toed ungulates), and Carnivora (cats, dogs, seals, and their allies). All mothers of the mammals one finds on the menu at McDonalds, Subway and Domino’s Pizza have placentas in their wombs and mammary glands (breasts) to nurse their young.

Our brains

All mammals have a remarkably similar brain structure and nervous system. Of all the vertebrates, it is we mammals that have the biggest and most complex brain for our body size. On average, a mammal has a brain roughly twice as large as that of a bird of the same size, and ten times as large as that of a reptile of the same body size.

Size, although important (yes, when it comes to brains, size does matter), is not the only difference. There are also substantial differences in brain shapes. The hindbrain and midbrain of mammals are generally similar to those of other vertebrates, but dramatic differences appear in the front, which is greatly enlarged and altered in its structure as well.[iv] This front part of our brain, called the cerebrum (which controls functions such as memory and learning), is much larger in mammals than it is in other vertebrates.

The cerebral cortex also strongly distinguishes the brains of humans and other mammals from the rest of the animals on Earth. The cerebral cortex is an outer layer of neural tissue, and it is separated into two cortices by the longitudinal fissure that divides the cerebrum into left and right hemispheres. In non-mammalian vertebrates, the surface of the cerebrum is lined with a comparatively simple three-layered structure called the pallium. In mammals, however, the pallium becomes a complex six-layered structure that scientists call the neocortex.[v] Several areas at the edge of the neocortex, including the hippocampus and amygdala, are also much more extensively developed in mammals than they are in other vertebrates.[vi]


Consciousness is not an easy concept to define. It has been described as the state of being awake and aware of what is happening around you and of having a sense of self. The 17th century French philosopher, René Descartes, proposed the notion of "cogito ergo sum" ("I think, therefore I am"), which is the idea that the mere act of thinking about one's existence proves there is someone there to do the thinking. Descartes also believed the mind was separate from the material body — a concept known as mind-body duality. Yet if this concept were true, how could you knock a person unconscious by simply knocking him on the head (and cause him to lose some memory, if the knock was forceful enough)? There must be something in the head that makes consciousness possible. I believe that “something else” is what all mammals have in common.

When mammals experience elevated levels of stress, their bodies release hormones that degrade the quality of the meat on their bones, producing what the industry calls “pale soft exudative” meat from pigs and "dark, firm, and dry" (DFD) meat from cows or sheep.

These stress hormones, such as adrenaline, cortisol, and other steroids, can lead to cardiac problems, impotency, and general fatigue in the humans that consume that meat. [vii] This phenomenon is seen only in mammals -- perhaps because mammals have the consciousness to know they are about to be killed and to freak out about it.

Some people may argue that humans are the only mammals with consciousness and a conscience. It makes sense to me also that if we want to eat mammals, we would need to take this position, because if we became fully conscious of the consciousness in all mammals, we could not in good conscience eat them. I do believe this view will change over time, as we become more aware of and more respectful toward our fellow mammals. After all, it was not all that long ago when in my own country, the United States, those of European descent classified humans of African descent as being legally only three-fifths human.[viii] It is now commonly accepted in America that all humans are in fact created equal. When we discover and accept that all mammals have a consciousness as we do, we may come to the obvious realization that the way we treat and eat them should be reconsidered.

Cultural and religious taboos

There are individual cases where modern societies mull over the morality of eating our fellow mammals. In North America and Europe, most people I know would shudder at the thought of eating “man’s best friend,” the dog. However, we won’t hesitate to chow down a hot dog, if it is made from the dog’s close cousin, the pig – which according to most studies is much smarter and intuitive than a dog. Pigs have outperformed three-year-old human children on cognition tests and are smarter than any domestic animal. Overall, the research suggests that pigs have excellent long-term memories and are skilled at mazes and other tests that require them to locate specific objects. They have even been taught to put together simple puzzles – something a chicken or a turkey could never do.[ix] My point? If you eat a hotdog, make sure it is made of chicken or turkey.

About a third of the planet’s population -- who are adherents to both the Jewish and Islamic faiths – will not eat pork because of Scripture. But long before the emergence of the Old Testament and the Qur’an, people in the Middle East had largely cut pigs from the available menus. This decision was probably for economic and health reasons once chickens were domesticated. Chickens are a more efficient source of protein than pigs are and only require 900 gallons of water to produce two pounds of chicken, while it takes 1,500 gallons of water to produce two pounds of pork. Also, chickens produce eggs, an important secondary product that pigs do not offer. Chickens are much smaller and can be consumed within 24 hours of being killed, thereby eliminating the challenge of preserving large quantities of meat in a hot climate. Chickens are also easier to transport than pigs, and thus they were probably selected as the animal protein of choice by our semi-nomadic ancestors.

Indians also have a special mammal that is taboo for their dinner table. In India as well as other communities of Hinduism, such as Trinidad, Bali, and Fiji, killing and consuming cows is a sacrilege of the highest order.

Most Americans would likely gag at the thought of eating horse meat. However, horses are considered a delicacy in many countries around the world. Mexico, France, Switzerland, Kazakhstan, Belgium, Japan, Germany, Indonesia, Poland, and China are among the nations where you will find horse meat on the menu in many a fine restaurant.

In 2002, as the Republic of Korea prepared to host the World Cup, Brigitte Bardot, the French actress turned animal rights activist, led a global campaign against Korea’s practice of eating dogs, calling it "barbaric." The International Federation of Football Associations (FIFA) received thousands of calls and letters condemning the practice. Korea fought back, led by the opposition in Parliament. Support was strongest among the patrons of the 6,000 restaurants that thrive on a mixture of dog stews, soups and satays washed down with alcoholic drinks flavored with pulverized cat. [x]

The amazing realization for me is that dogs somehow sense when humans eat other dogs. I know this through an experience I had many years ago. After dining on some roast canine in the remote Northern province of Benguet in the Philippines, nearly every dog I passed after that meal on the dusty street looked at me and growled. That was the first and the last time I ate dog meat.

Most Westerners are appalled by and sickened at the thought of eating dogs, and most Americans would also shudder at the thought of a horsemeat hamburger. One of the objectives of this book is to get the reader, if currently an omnivore, to consider broadening his or her circle of compassion to include other mammals.

The food chain

What I clearly seek to dispel here are the common assumptions that we need to eat mammals to survive. For humans, eating meat is a choice, not a necessity. We are omnivores, not carnivores. It would be altogether a different matter if we found ourselves in a position where we need to kill something to survive or in a desperate scenario where the choice is either eat or be eaten. But when we have a choice, between killing a mammal or finding something else to eat, my goal is to present a compelling case for people to choose the latter. This book is my personal attempt to achieve that goal.

In ecology, a food chain is a series of organisms that eat one another, so that both energy and nutrients flow from one to the next. For example, if you have a steak for dinner, you might be part of a food chain that looks like the following: grass → cow → human. Each stage of this process is called a trophic level.

The primary producers include a group of organisms that are producing their own food. As with the given example, plants are primary producers based on their ability to manufacture their food through photosynthesis. At the next trophic level in a food chain or ecological pyramid, the organisms feed on the primary producers and are referred to as primary consumers, i.e. herbivores, such as cows and hippos, which eat the grass. Organisms that feed on the herbivores, called predators, occupy the next trophic level. At the top are the apex predators like the lions and tigers and bears.

Humans often believe they occupy a natural position at the top of this ecological pyramid. However, science does not support this assumption. In 2013, a group of French researchers calculated human trophic levels, and found that on a scale of 1 to 5, with 1 being the score of a primary producer (a plant) and 5 being a pure apex predator, they discovered that based on their diet, humans score only a 2.21—roughly equal to an anchovy or pig.

These researchers, led by Sylvain Bonhommeau of the French Research Institute for the Exploitation of the Sea, used data compiled by the United Nations Food and Agriculture Organization (UNFAO) to construct models of people’s diets in different countries over time. They then used that data to calculate our human place in the food chain, using data from 176 countries from 1961 to 2009. Calculating the trophic level for humans was very straightforward: If a person’s diet is made up of half plant products and half meat, his or her trophic level will be 2.5. More meat, and the score increases; more plants, and it decreases.

Their results confirmed common sense. as a species, we are primarily omnivorous, eating a mix of plants and animals, rather than being top-level predators that only consume meat.[xi] The best evidence for this assertion is probably our teeth. Like carnivores, we have incisors for biting, tearing and ripping apart meat, as well as molars for chewing (as herbivores do). Animals with the same kind of diverse teeth tend to be omnivores.

In other words, we can eat meat, but we don’t have to eat it. It is a choice. Also, when we do choose to eat meat, we can choose which type of meat we want to eat – mammal or other animals that do not include our close cousins. However, in many developed countries today, such as the United States, people are choosing to eat mammals every day – and quite often a few times a day.


The fast food chain

Nothing exemplifies the fixation on fast food in America more than the ubiquitous presence of the Golden Arches. The coordinates of N 45.45955 W 101.91356 identify a spot in South Dakota that has the peculiar distinction of being the “McFarthest point” in the lower 48 states.[xii] The nearest McDonald’s is 107 miles away from that spot, as the crow flies, or 145 miles away if traveling by car. It means that any hungry motorist is always within a full tank of gas of a McDonald's restaurant anywhere in the continental United States. That is just in one country – albeit a country that consumes a lot of hamburgers. Worldwide, as of early 2019, more than 69 million people eat at 36,899 McDonald’s restaurants and consume “more than 75 hamburgers per second, of every minute, of every hour, of every day of the year,” according to the company’s Operations and Training Manual.[xiii]

Because many of us have chosen to eat meat every day, industrialized global meat production has transformed the food chain into a fast-food chain. In the United States alone, the total mammal meat production (beef, veal, pork, lamb and mutton) totaled 52.1 billion pounds in 2017, three percent higher than the previous year. These figures come from the United States Department of Agriculture[xiv] but they do not include the actual number of mammals killed. The Humane Society of the United States on its website puts that total for 2015 at 28.7 million cows (an increase of 4.3 percent from the previous year), 115 million pigs, 2.2 million sheep and lambs – all raised and slaughtered within a single year in the United States alone. In Fiscal Year 2018, according to the North American Meat Institute website, there were 835 Federally-inspected livestock slaughter plants in the United States. An additional 3,773 plants process mammal meat, but they do not slaughter them.

In developing countries, according to the FAO, mammal meat consumption has been growing at five to six percent annually.


This growing expansion of livestock production has severe environmental implications, for example, the expansion of land for livestock development. Livestock sector growth has been a prime reason for deforestation in many countries, such as Brazil and Argentina.

Global industrial mammal meat production has quadrupled in just the span of my lifetime, from 86 million tons in 1963 (the year I was born) to the current total of 340 million tons (308.4 trillion kg).[xv] Yet the human population of the planet has only a bit more than doubled. This trend of meat production is projected to continue, especially as the growing urban middle classes in China and other emerging economies adopt the burgers-and-steaks diet of North America and Europe. According to the UNFAO, global meat production could increase to 501 million tons by 2050.

The pet factor

If all the cats and dogs currently living in the United States were together in their own country, they would rank 5th in global mammal meat consumption, behind only Russia, Brazil, the United States and China. In other words, cats and dogs in the U.S. eat more meat than all of the people and their pets in France and Germany. As outlined here in the chapter on environmental considerations, producing all this meat has an enormous impact on the environment. According to research on climate change conducted by Professor Gregory Okin at the University of California at Los Angeles (UCLA), total meat consumption by dogs and cats is responsible for the emission of 64 million tons of carbon dioxide a year – around the same climate impact as driving 13.6 million cars.[xvi]

This situation can be easily rectified with some effort. The cat is considered by scientists to be a strict carnivore while the dog is considered to be an omnivore. That means that cats eat meat – but it does not have to be mammal meat. Although we tend to think that our dogs need meat, they actually will eat everything. I further address the issue of what to feed our pets in the last chapter, Final Thoughts and Reasonable Recommendations.

The next chapters address the different arguments, or reasons, for reducing or avoiding mammal consumption, beginning with the first reason, which is your health. I then look at the impact that industrialized livestock production is having on the environment, before turning to the economic arguments that suggest we should stick to fish, chicken or vegetables.



[i] Fishbase, see

[ii] Barrowclough GF, Cracraft J, Klicka J, Zink RM (2016, November 23) How Many Kinds of Birds Are There and Why Does It Matter? PLoS ONE 11(11): e0166307. Retrieved from

[iii] Milman, O. (2018, 21 December) Why eating less meat is the best thing you can do for the planet in 2019. The Guardian. Retrieved from

[iv] Barton, RA; Harvey, PH (2000, June 29). "Mosaic evolution of brain structure in mammals". Nature. Retrieved from

[v] Aboitiz, F; Morales, D; Montiel, J (2003, October 26). "The evolutionary origin of the mammalian isocortex: Towards an integrated developmental and functional approach". Behavioral and Brain Sciences. Retrieved from

[vi] Barton, RA; Harvey, PH (2000, June 29). "Mosaic evolution of brain structure in mammals". Nature. Retrieved from

[vii] Freund, D. (2011, August 25). How animal welfare leads to better meat: A lesson from Spain. The Atlantic. Retrieved from

[viii] Johnson, T. (2015, August 5). We used to count Black Americans as 3/5 of a person. For reparations, give them 5/3 of a vote. The Washington Post. Retrieved on ( add dates for these sources for retrieval dates) from

[ix] Zolfagharifard, E. (2015, June 12). Move over Lassie: IQ tests reveal pigs can outsmart dogs and chimpanzees. The Daily Mail. Retrieved from

[x] McElroy, D. (2002, January 6) Korean outrage as West tries to use World Cup to ban dog eating. The Telegraph. Retrieved from

[xi] Bonhommeau, S. Dubroca, L. Le Pape, O. Barde, J. Kaplan, DM. Chassot, E. and Nieblas, AE. (2013, December 17) Eating up the world’s food web and the human trophic level. Proceedings of the Natural Academy of Sciences. Retrieved from

[xii] Allen, N. (2009, October 19). McFarthest point in the US from a McDonald's. The Telegraph. Retrieved from

[xiii] Duprey, R. (2016, October 11). 15 Fascinating Things You Probably Didn't Know About McDonald's Corp. The Motley Fool. Retrieved from

[xiv] USDA (2018, January) Retrieved from

[xv] Food Outlook: Biannual Report on Global Food Markets, p. 7. FAO, October 2015. Retrieved from

[xvi] Okin GS (2017) Environmental impacts of food consumption by dogs and cats. PLoS ONE 12(8): e0181301. Retrieved 2019, January 13 from

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