Omnivore Vs. Vegetarian
Commentary by Jim Walker
Originated: 05 Sep. 2006
Additions: 09 Mar. 2016
Evolution dictates our lot in life with the undisputable fact that in order to survive, all animals, including us, must consume the by-products of DNA (i.e., living things). Since living things provide the only DNA sources available, we must eat the flesh of life (plants and/or animals) to continue our existence. This presents a dilemma and a moral problem if we consider killing life as immoral and conserving life as moral. I hope to clarify some of the problems and to dispel some of the myths about eating plants and animals both from a health and moral perspective.
We can have no argument about the following: all animals consume either plants, animals or both. Every specie of animal falls into the category of either carnivore, herbivore, or omnivore (other classifications exist such as frugivore, granivore, insectivore, etc. but these fall under sub-classes of the three major groups).
Eating high concentrations of protein (meat) has evolutionary benefits for carnivores. Meat serves as an efficient way to build a body and to economically replenish lost muscle tissue. Carnivores usually have lean, fast moving bodies, good for running down or overpowering prey. They have short digestive tracts, good for quickly eliminating unnecessary mass and allowing a high-muscle, low-fat balance. Humans do not fall into the carnivore group.
Herbivores (vegetarians), on the other hand, need longer intestines to break down and assimilate tough-to-break-down plant fibers. This means that the food stays in the gut for long periods of time. Most herbivore mammals have higher fat concentrations than carnivores and they don't have the speed compared to carnivores. Just observe the large bellies of the great apes, and ruminants (oxen, cattle, sheep, etc.), and you will see how obese they seem compared to hunter-carnivores. Humans do not fall into the herbivore group either.
Homo sapiens, of course, fall into to the omnivore class. Through natural selection we evolved the teeth of omnivores, good for grinding grain, stripping leaves, and eating meat. We have long intestines (somewhere between carnivore and herbivore intestinal tracts), and a digestive system that will break down both acidic and alkaline based foods (protein, carbohydrates, and fat). Our closest relatives, the chimpanzees, also have an omnivore diet (not only do they eat plants and fruits but they hunt and eat monkeys, for example).
Humans beat all other omnivores by a large margin (omnivore comes from the Latin: omni, or everything). People will eat anything including bacteria, fungus, plants, and animals. From the plants we will eat roots, bark, sap, leaves, berries, fruits, nuts, flowers, and seeds. We will eat any animal, including worms, insects, crustaceans, fish, amphibians, reptiles, birds, and mammals (and in some cases, people). We will eat their meat, fat, eyes, brain, organs (including testicles), bones and shells (for calcium), milk, and blood. Humans will even eat rotten food such as cheese and sour cream (due to decomposition from bacteria). Risen bread and alcohol drinks made by fermentation comes about from the waste products of yeast. Japanese people eat natto, a form of rotten fermented soybean. Ræst kjøt comes from rotten mutton. Humans eat lots of rotten fish. The Icelandic delicacy hákarl comes from rotten shark; the Swedes love surströmming, a rotten herring dish; Ræstur fiskur describes a half-dried rotten fish delicacy; the Russian tresca comes from decomposed codfish. Some humans even drink urine. Yes urine*.
* The ancient yogi religious practice known as "amaroli" involves drinking one's own urine everyday (still practiced by millions of people). This odd practice comes from the yogi text, "Damara Tantra" called Shivambu kalpa vidhi (auto-urine). Urine contains the hormone melatonin secreted from the pineal gland in the brain. This hormone probably accounts for the meditative "spiritual enlightenment" experienced by Indian shamans.
The Bible even records humans eating their own feces and piss (II Kings 18:27). Egads! What won't we eat? We even eat supernatural meat, such as meat from human-god flesh in what Christians call, "Jesus," during "Holy" communion. Catholics believe this as real flesh and blood, and if you don't believe it, the Church curses you (according to the Council of Trent).
And if people wish to commit suicide, humans will even eat or drink poisons (hemlock, mushrooms, arsenic, cyanide, ricin, etc.)
Advantages and disadvantages of eating meat
Just because an omnivore specie eats plants and animals does not mean that all animals in that species must eat both flesh and plants. Nor does it mean that an omnivore must eat equal parts of animals and plants. Humans can live off animals only or plants only, but excluding either does not necessarily mean a healthier life, regardless of the claims of vegetarians. In spite of our omnivorous nature, human diets lean more toward plants than meat. Our long digestive tract resembles that of vegetarians more than carnivores, and the knowledge of early humans shows a more agricultural, plant eating dietary tendency than it does hunting and eating animals. Most herbivores require the aid of bacteria to digest cellulose and as a result, they evolved a caecum in the gut that houses bacteria that acts like a fermentation chamber. Some think that the human appendix "devolved" from a larger caecum from our ancient vegetarian ancestors. I suspect that when humans began cooking their food, it further reduced the need for a large caecum because heat naturally breaks down cellulose, or perhaps our bigger brains and tool making abilities enabled us to separate the cellulose from our food. There also exists some evidence to suggest that human meat eating began from scavenging rather than hunting (hunting, according to the theory, evolved later as we developed bigger brains). According to some biologists, when our human ancestors began cooking meat, it paved the way to major changes in the anatomy of humans such as smaller faces and teeth after they threw off vegetarianism. Chewing cooked meat requires less time than chewing fibrous vegetables. The great apes, for example, spend most of their time chewing. Eating cooked meat allowed early humans to spend more time on other productive things (tool making, language, social activities, etc.) rather than eating and digesting.
According to 20th century theories, the main health problem with eating animals comes from the fat. Most animals contain high levels of saturated fat that when eaten, correlates with hardening of the arteries, and heart disease (but please note that correlations do not prove causality). Dairy products also contain high amounts of fat. And all animal products contain cholesterol, which, according to the American Heart Association and other health groups, claim to contribute, if not cause, atherosclerosis. However, many have challenged this old theory and slowly medical science has evolved away from this lipid hypothesis. For example, the Department Of Health, in their Dietary Guidelines for Americans, announced in 2015 that: "Cholesterol is not considered a nutrient of concern for overconsumption." The British Medical Journal also announced that saturated fat is not the major issue. There was also a meta-analysis (of over 347 thousand people over 23 years!) study on the effects of saturated fat with cardiovascular disease, and it showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. However, there does seem to be a link to processed red meat and a higher risk of heart failure and death.
As odd as it may seem, not eating enough meat might also increase the risk of strokes in some people. A study among Japanese people has shown that Asian populations (poor in animal consumption, and thought to explain the high rate of strokes), showed that a higher intake of animal fat and cholesterol can significantly reduce the risk of cerebral infarction death (stroke). Whether the higher rate of stroke in Japanese people comes from eating saturated or trans fats from plants instead of meat, or from a poor source of the vitamin Bs, or other things, remains a mystery.
The "bad" form of animal fat supposedly not only comes from the flesh but also from milk and cheese. Milk products probably accounts for more allergies than any other source but it probably stems from casein (the main protein in milk and cheese) rather than from fat or cholesterol. Moreover, the dairy industry wants us to believe that the best source for calcium comes from dairy products, yet Americans, who consume large quantities of milk and cheese have among the largest problem of osteoporosis in the world. Only Homo sapiens drink milk after weening, and from another species milk! Interestingly cows and goats, who give us dairy products, get their calcium entirely from plants.
Only animals make cholesterol. We need cholesterol in order to live. In fact our animal bodies make lots of cholesterol even if we ate no cholesterol at all. Every cell membrane in your body requires cholesterol. Cholesterol also serves as an important component for the manufacture of bile acids, steroid hormones and fat-soluble vitamins including Vitamin A, Vitamin D, Vitamin E and Vitamin K. According to medical convention, High-Density Lipoproteins (HDL) describe the good cholesterol and Low-Density Lipoproteins (LDL) describe the bad cholesterol. In actuality, describing cholesterol as good or bad makes no sense because HDL and LDL describe lipoproteins, not cholesterol itself. HDL and LDL simply means High-Density Lipoprotein and Low-Density Lipoprotein, respectively. There are other lipoprotein types too such as VLDL (Very-Low-Density Lipoprotein), IDL (Intermediate-Density Lipoprotein), and others, but doctors usually describe only two types (HDL, LDL). The lipoproteins are protein structures that carries fat and cholesterol through the blood. Both HDL and LDL transport the same kind of cholesterol, so putting goodness or badness just on cholesterol results in confusion. The problems associated with LDL result from the degradation of the protein structure itself which may develop from various causes such as toxins, oxidation of cholesterol, free radicals, lack of antioxidants, etc.
Both plants and animals have saturated and trans fats, so simply eliminating animal fat in the diet does not necessarily reduce bad fat consumption. In fact, some vegetarian diets yield higher levels of saturated and trans fats (including hydrogenated oils) than meat-vegetable diets! Moreover, there exists a growing awareness that unsaturated fats, especially polyunsaturated fatty acids, may contribute more to atherosclerosis than saturated fat (because polyunsaturated fats oxidize easier and can cause LDL to degrade and once inside the inner lining of arteries, it can result in atherosclerosis). [click here for this theory] So what to do?
As stated above, recent studies have shown little or no cause of atherosclerosis from either saturated fat or cholesterol. On the other hand, evidence does show harmful effects of trans fats and hydrogenated oils, both of which occur in plant and animal food depending on how they are prepared and cooked. So the evidence points to avoiding trans fats and hydrogenated oils and replace them with healthy fats. The better unsaturated fats come in the form of Omega-3 fatty acids. Omega-3 derives mostly from three types of oily foods: seeds (especially flaxseed), nuts (especially walnuts), and fish (especially wild salmon, black cod, sardines). The Omega-3 family comes in at least two varieties: short-chain and long chain (a 'chain' refers to the length of its molecular structure). Long-chain Omega-3s serve as the best form because of the way the body processes them, and only animals produce long-chain Omega-3s. Long-chain Omega-3s act faster and more efficiently than do short-chain Omega-3s. By far the best source of Omega-3 fats come from fish, especially wild salmon. The short-chain Omega-3s occur only in plant foods. The evidence so far shows that fatty fish provides the best source of unsaturated fats, especially omega-3 fatty acids. Omega-3s are thought to be beneficial to health because they lower triglycerides, can curb rheumatoid arthritis, lower levels of depression, and many other health benefits. This means that the healthiest diets, should include some animal flesh.
In spite of the evidence that polyunsaturated fats offer health benefits, other studies have shown that consuming high amounts of polyunsaturated fat (especially omega-6), especially when not consuming omega-3 fats or anti-oxidants, may increase the risk of metastasis in cancer patients and possibly increase the risk of cancer in healthy people. Because polyunsaturated fats tend to oxidize, this leads to an increase of free radicals. However, studies have shown that low dosages of Coenzyme Q10 reduces this oxidation. These studies suggest that we should not have too much polyunsaturated fat in our diets and always accompany them with omega-3 fats, and anti-oxidants. Nuts, for example, contain polyunsaturated fats but they also contain fiber and are loaded with anti-oxidants.
Meat or dairy products offer the only foods that contain enough of the essential amino acids required by the human body. A vegetarian, however, must choose from a variety of vegetables in order to get the right amino acid combination. Also, plant protein has a relatively low biological value and digestibility compared to animal protein. Moreover, the amount of protein needed per day demands that the vegetarian must eat enormous amounts of plant food per day just to get enough protein in their diet.
Furthermore, the best and most abundant source for B vitamins (especially vitamin B12) come from animal products (yes you can get B vitamins from yeast and other plants but a pure vegetarian diet has very little B vitamins unless supplemented by vitamin pills, many which contain animal products). Also, some studies suggest that carnosine, only found in meat, has beneficial antioxidants that might explain why vegetarians don't live longer than some groups of people who include meat in their diet (see below). Carnosine supposedly protects against age-related diseases. Also read: "Glycation, ageing and carnosine: Are carnivorous diets beneficial?"
The point of all this aims to show you that just eliminating animal products does not necessarily make you healthier nor does it allow you to live longer. I have yet to see any evidence that shows that vegetarians or vegans live healthier or longer on average than non-vegetarians who eat healthy. Studies have, however, shown that vegetarians live healthier and longer than those on typical American diets that contain meat but that doesn't say much because most Americans eat far too much processed meat, sugar, salt, sodium nitrate, and other chemicals and hormones. What we need are more studies that compare health-conscious vegetarians vs. health-conscious omnivores. So far the health-conscious omiivores are winning (see below).
Who lives the longest?
Much evidence suggests that an optimum diet should have some amounts of animal products (not surprising from an animal that evolved into an omnivore). The major problem of eating meat comes with eating too much meat and fat or meat from processed grain-fed animals. Americans, for example eat so much meat and fat that many of our diseases stem from this, especially if it leads to obesity. The best diets in the world (based on health and long life) have some animal protein in their diets. The Okinawa diet (the diet of people from the Ryukyu Islands that used to have the longest life-spans) included small amounts of fish and pork (with the fat boiled off). The highly acclaimed Mediterranean diet also includes moderate consumption of dairy products, moderate to high consumption of fish and low consumption of meat products. Some people claim that the long living Vilcabambans of the Andes live on a strict vegetarian diet but according to Joseph Correa in his book, The Vilcabamba Diet, "they eat a lot of fruit, vegetables, and protein derived foods (chicken, eggs, turkey, fish, etc.)" Note, although the people of Vilcabama live long, the claims of the number of centenarians has been exaggerated (see: Vilcabamba: the town of very old people).
Blue Zones are areas around the world where people live the longest and healthiest. Dan Buettner, the National Geographic and the world's best longevity researchers have, so far, discovered five Blue Zones where people live to 100 at rates 10 times greater than in the United States. These areas are in Okinawa (Japan); Sardinia (Italy); Nicoya (Costa Rica); Icaria (Greece); and among the Seventh-day Adventists in Loma Linda (California). Only one zone (Loma Linda) consisted of true vegetarians and vegans, but even here many of the Seventh-day Adventists were not true vegetarians. In fact the ones who lived the longest were the pesco-vegetarians. Pesco-vegetarians are those who eat fish but rarely meat, and note that fish are animals, thus pesco-vegetarians are not true vegetarians. (If fish eaters are vegetarians, then I get to call myself a carno-vegetarian). Moreover, the researchers had difficulty in discerning between associations, and cause-and-effect links. The longevity of these people may not be due to their diet alone (or at all) but to other things such as low stress, clean environment, exercise, a health-conscious attitude, genetics, some other unknown criteria, or a combination of these.
Moreover, much, if not all, of the blame for the unhealthiness of meat may not come from the meat itself but from how the meat is prepared and cooked or how the animal was raised. If you grill or cook meat in high heat, it can produce harmful carcinogenic hydrocarbons, or if your diet includes lots of fried meat, especially fried in vegetable oil, can lead to all sorts of health problems. Even a diet with fried fish can lead to a short life no matter how much of a pesco-vegetarian you are. If you eat meat from cattle raised in America, the cattle was most likely fed grain instead of grass (the natural food for cows), and this can lead to health problems. But if you eat grass-fed meat cooked properly, the health problems seem to vanish. It's interesting that the Masai tribes in Africa show little clinical evidence for atherosclerosis even though they have a life long diet of exclusively meat, animal fat, and milk and they have low levels of serum cholesterol and little evidence for arteriosclerotic heart disease (source, source). The Inuit Indians from Alaska eat massive amounts of seal and walrus meat with lots of fat, along with moose, caribou, reindeer, and fish and almost no vegetables (or at least they used to before Westernized diets became available to them), yet they had cardiac deaths about half that of Americans (source, source, source).
Research has begun to improve the health benefits of meat by means of better feed, and genetically altering animals to produce healthier meat. Sheep farmers in Wales, for example have boosted Omega 3 levels in lamb. Pig genetics company JSR has succeeded in developing a feed high in Omega-3 for pigs. Researchers have cloned Omega-3 producing pigs that should reduce the risks for heart disease. Perhaps one day we can eat Omega-3 bacon and reap the same benefits of eating wild salmon!
If you wish to eat the healthiest diet, you cannot use two-valued-logic to determine your diet. Becoming exclusively a vegetarian or a vegan does not necessarily provide you with the best health diet, nor does eating lots of meat. Moreover, "healthy" foods differ by a large margin depending on the individual. An Israeli study discovered that even after eating identical foods, the way those foods metabolized differed dramatically from one person to another (source). Also, some people have an intolerance to dairy foods (like myself) and some have an intolerance to certain vegetable foods. Some foods can cause allergies (sometimes so severe that it can cause death). Some people claim to feel better when they eliminate meat while others feel better with meat in their diet, and then there are some people who seem to thrive on any kind of food. Moreover, we are beginning to understand that our microbiome (the microorganisms in our gut) play a much larger role in diet and health than we ever thought before.
One disadvantage of eating animals, though, comes from having to kill them. Not everyone thinks this as bad, of course, but if you've ever contemplated killing animals that you love, then this becomes an ethical problem.
The ethical problems
“The greatness of a nation and its moral progress can be judged by the way its animals are treated.”
Anyone who has observed a cow, sheep, or pig, or bird close up, knows how delightful these creatures can seem. We instinctively impinge our own antromorphic feelings toward them, and many times we want to protect them instead of killing them for our own "selfish" reasons. Many people become vegetarians solely for this reason. Does this antromorphism represent something real or do we simply misjudge? We certainly don't have an inborn instinct to kill animals the way carnivores do. Humans must teach other humans to kill (and that means killing humans as well as animals).
Theologians and philosophers, for centuries, have assured us that animals have no feelings. Aristotle didn't recognize animal's feelings at all. He elevated reason above feelings as the prime reason for human existence. in his Politics, he wrote, "Plants exist for the sake of animals, and brute beasts for the sake of man - domestic animals for his use and food, wild ones for food and other accessories of life, such as clothing and various tools. Since nature makes nothing purposeless or in vain, it is undeniably true that she has made all animals for the sake of man." René Descartes associated thinking with feeling and because he thought animals don't think, they can't feel. He thought that the seemingly painful cries from animals as nothing more than "broken machinery." Only man can achieve consciousness, thought and feelings, he "reasoned." Immanuel Kant in his Lecture on Ethics wrote, "so far as animals are concerned, we have no direct duties. Animals are not self-conscious, and are there merely as a means to an end. The end is man." Theologians, of course, for centuries taught that only humans possessed a soul (whatever that means) and animals don't deserve the same respect. The belief in the Bible's dominion over all species have excused the worst and indifferent behavior toward animals. And this includes the treatment of slaves who Christians thought of as sub-humans, and not capable of reason and feelings. Even today, we label our enemies as beneath us. For example, many people from Western countries consider citizens living in Islamic "terrorist" countries as somehow less human, calling them barbaric animals. They see no problem in killing thousands of innocent civilians, as long as they don't have to listen to their cries. The same goes with killing animals (out of sight, out of mind). All of these believers got it wrong.
Of course we cannot measure directly the feelings of animals, but then again, we cannot directly measure the feelings of humans either (after all, we exist as animals too). Yes, we can listen to the expression of feelings through the language of humans but this has no more direct evidence for feelings than do the cries of animals when they suffer pain. Only through deduction, by comparing our own feelings with those around us (including animals), can we evaluate their feelings. And then we have the growing science of neurology and biology that has overturned the incorrect beliefs practiced throughout centuries.
All mammals and birds have social lives. That means complex brains. Mammal brains, especially, resemble our own mammal brains. The structure and function of non-human mammal brains do exactly what the structure and function of human brains do, with only a matter of degree. The difference comes mostly from the large cerebral cortex and language centers of human brains. The cerebral cortex involves our higher ability to think and plan which, of course, appears larger in humans. But for the emotional and feeling part of the brain, namely the limbic system, the function and relative size appears the same in mammals.
Biologists generally think that brain size relative to body size relates to intelligence. Therefore animals with larger brain to body size, generally have higher intelligences than those with smaller brains. Humans, chimps, and dolphins, for example exhibit large brain to body sizes, and this derives mostly because of their larger cerebral cortexes. But when it comes to the emotional, feeling part of the brain, mammals have just as large a limbic system (which is where emotions live) to body weight as do humans! This implies that non-human mammals feel just as much pain and pleasure as humans do.
The philosophers associated thought and reason with feelings and emotion, but brain physiology proves this wrong. One can feel, and exhibit strong emotions without a frontal cortex at all! (This comes from extensive examples of brain damaged people). If you have a well functioning limbic system, you will feel regardless of your lack of intelligence. (This applies to politicians too.)
Mammals, like humans, form special bonds with their kin that involve special obligations of care. They must interact with each other and this involves sensing what their kin feel. Although they do not communicate through abstract language like we do, they communicate their feelings through sounds, barks, bleeps, chirps and physical movement. Anyone who has owned a pet knows more about how animals feel than all the theologians and philosophers combined.
Scientists have gone farther. Studies of farm animals have shown that they have the capability of feeling strong emotions such as pain, fear, anxiety and even happiness. Moreover the studies reveal that their emotions resemble those of humans! (see The secret life of moody cows). Biologists have even found evidence for the perception of pain by fish (see Fish do feel pain, scientists say).
The evidence overwhelms. Animals feel pain and at least the higher animals (including farm animals), have highly developed emotional centers. So what do we do about the ethics of killing animals for food if they can feel emotions like we do?
Unfortunately in the short term, no solution exists. If you wish to determine the killing of animals as the sole basis of wrongful actions, then no solution exists. However, if we use pain, emotions and cruelty as the moral hinge-pin to determine ethical behavior then, at the very least, we can eliminate the pain and suffering of animals while still enjoying the benefits of animals for human consumption.
The debate about animal ethics involves how we should treat non-human animals. In the United States, we already have a few laws regarding the treatments of animals, especially pet animals, animals used for scientific research, and animals used in the entertainment industry. But why shouldn't we treat farm and wild animals any different? If your neighbor treats your pet in a cruel fashion, they can end up in jail. But if a farmer does the same to a pig or a chicken, the law remains (mostly) silent.
The animal rights problem resembles the ethical problems of slavery, the treatment of women, and minorities. Our ethical thoughts evolve along with our culture and our bodies, and the same can happen in regards to animal rights. Of course by rights, we do not mean voting rights or freedom of speech, but as Michael Shermer suggests, "We can begin with the most basic rights granted by the U.S. Constitution: life, liberty, and the pursuit of happiness."
We cannot blame ourselves for immoral behavior just because we eat animal flesh. We evolved as omnivores. Some evolutionary scientists think that meat eating lead to our big brains. We can't help our evolutionary past. But we did not evolve as cold blooded carnivore killers like sharks or crocodiles, either. We must teach our young to kill animals. Our ability to hunt and kill animals does not come from instinct but rather from social conditioning. And this gives us reason to modify and evolve our ethical behavior without contradicting our animal nature.
Consider this: domestic farm animals evolved to live with humans. Through artificial selection their genes have altered to adapt with us. They can no longer live in "natural" wild environments without us. Our genes, likewise, have adapted to living with them. We can tolerate their disease causing germs and have adapted to consume their milk (lactose intolerant people usually have a genetic history free from dairy farming). This evolutionary bargain benefits both them and us. Approximately 10,000 years ago humans along with their livestock and pets accounted for about 0.1% of the mass of vertebrate life on earth. Today they account for over 97% with cattle consisting of most of the mass. (This thought first came from Paul MacCready, the designer of the first human-powered aircraft) now called the MacCready explosion or MacCready effect).
Without humans, cows, sheep, and other farm animals would not have survived as well without us, and perhaps not at all. Some domesticated animals have already met this fate such as the aurochs (Bos primigenius). They became extinct because of competition on its feeding ground by domesticated cattle, disinterest, and other factors. The last aurochs disappeared in Poland in 1627. Today, according to the World Watch List for Domestic Animal Diversity, one third of farm animal breeds face extinction. So if you really care about the fate of domesticated animals, you might want to consider a campaign to get more people to consume them.
Also consider the life spans of wild animals compared to domesticated animals. Wild animals don't have the protection against prey and diseases as do domesticated animals and they usually live short lives. Protected White-tailed deer, for example, have a life expectancy of up to 15 years, but in the wild, males live an average of 2 years, and females live around 3 years That's about a five-fold difference in life span!. I don't know the life-spans of pre-historic wide cattle and sheep, but I'll bet domesticated animals live as long or longer than the pre-historic versions (not counting veal, which would violate the animal rights argument presented here).
We provide domesticated animals protection from predators, food, and the ability to raise their young. In return, they provide us with food and clothing. Nor should you argue against eating them because they can't communicate their reasons for staying alive. Animals can't communicate, and they don't have the capability to reason. They can only express their instincts to live through feelings and desires. If we kill them without their ability to feel pain or discomfort then we have gone a long way to solve the ethical problems.
To impress the matter further, imagine this thought experiment: Earth receives a visitation by super-intelligent benevolent aliens and they give us two choices:
1. We will not bother you and will leave you to live your short lives as you wish.
2. We will protect you from harm and we can increase your life spans three-fold. We will not interfere with your life other than to make you live longer and happier. You will still have all the freedoms you want, but you will not suffer, feel pain, or have diseases. However, after you have reached some 300 years old, we will painlessly put you to death. We will then do what we wish to your dead bodies.
I don't know about you but I would seriously consider option 2. Wouldn't you?
So the first step in a workable ethical solution involves allowing animals the same basic rights as human animals. Give them life, protection, the ability to live their lives according to their nature, at least well past reproduction age, and when it comes time to kill them, do it quickly, without pain, and without upsetting the animals around them. This Faustian bargain may not provide the ultimate ethical solution but it does provide a step in the right direction.
"I think using animals for food is an ethical thing to do, but we've got to do it right. We've got to give those animals a decent life and we've got to give them a painless death. We own the animal respect."
If you practice a vegan life style and still think vegetarianism represents the most ethical position, then think again. If everyone on earth converted to a pure vegetarian diet, then what need do we have for domesticated farm animals? They can't live without us and if we no longer need their meat or hide, then we have no reason to raise them (except for a few to keep in zoos). If you think the free cattle roaming around the streets of India represents a solution, then you have not thought it through. These poor diseased starving creatures hardly represent an ethical solution any more than free-roaming feral cats and dogs, and they still require humans to keep them barely alive.
In human terms we would call this genocide. Ironical as it may seem, by eating animal meat we keep their species thriving. And what about those precious cats and dogs that we so dearly love? They live strictly as pure carnivores! Now what? If we eliminated meat from our diet, we would still need to kill animals to feed our carnivore pets. So if we eliminated raising animals for food, then our pets would become extinct. Whenever a vegan criticizes me for eating meat, I always respond, "What am I going to feed my cat?" The question for vegetarians then becomes: "Should I allow an animal live a short but generally happy life, rather than no life at all?"
The question that should really concern us involves the mistreatment of animals rather than their eventual demise, and this includes the cruelty of present-day confinement farming. Most people do not realize the horror that occurs in slaughterhouses and concentrated animal feeding operations (CAFOs). Putting birds in electrified cages, cows in disease filled pens, and darkened rooms and feeding them a cannibal diet, cannot possibly serve to produce a contented, much less a happy animal.
Of course one could also argue that most of these problems stem from human overpopulation and we could best solve them by simply reducing our numbers by ethically reducing the human population, not by war or disease, but by conscious birth control.
The ethical treatment of animals and genetically altering them, provides us with healthier alternatives and solves the moral problems of eating meat, but if you still consider killing animals as unethical then you still have a problem.
Fortunately science might solve this one too. Scientists have already grown small amounts of edible meat in a lab (also see New Harvest). Someday we may have the ability to grow meat in abundance without having to kill an animal to get it. Imagine eating the most succulent steak, genetically altered to produce the healthiest protein and fat (without cancer inducing hormones). Vegetables grown as meat! The company, Organovo, develops processses that 3D prints human and animal tissues that includes meat and leather (watch a TED talk about this, here.)
This, of course, would not solve the animal problem because if we could grow meat cheaper and more efficently than from raising and killing animals, we would not need farm animals and, again, we face the farm animal genocide problem.
In the far future, perhaps we could genetically alter animals so that they would want us to eat them. Douglas Adams explored this scenario in The Hitchhiker's Guide to the Galaxy, (in the episode, The Restaurant at the End of the Universe) where a very obliging Ameglian Major Cow, from a species of dairy animal specifically bred to not only have the desire for someone to eat him, but also capable of speaking English so as to communicate its desire. As the Dish of the Day, the Ameglian Major Cow offers his diners various ways to eat him.
We might also alter ourselves genetically or by evolving into a cyber sapien (as briefly described in Death and Time Traveling). The point here aims to show that we can evolve our behavior while reducing or eliminating the ethical problems of eating meat. The ultimate vegetarian solution involves evolving into an energarian, a pure energy consuming life-form that can think and feel but thrives on pure solar energy-- like a plant.