Why Vegan?

So why be vegan?
Amy Kauler

Read specifically about Dairy here.

Put simply, if the human body can lead a healthy lifestyle without the need for animal and animal by products – then it would mean a humans diet is based on ones appetite. So, why is it that these sentient beings are being slaughtered to feed an unnecessary want? Is it because people do not know you do not need meat and cows milk? Or is it just so ‘normal’ to eat it that doing anything otherwise makes you a lesbian-freak-anti-society-wrist slitting emo?

I am going to try my best to cover why we should be vegan by addressing every point, all the sources are credited at the bottom of this page. If you are a meat eater reading this you’re probably judging me because I am not a doctor or hold a piece of paper saying “I KNOW STUFF ABOUT FOOD!!!”. But I can assure you whatever I say is based on very common reasoning and logic.

First I would like to tell you a bit about me. My name is Amy Kauler. I was one of those on/off vegetarians all my life – I never seemed to stick with it during my time in Highschool because I always felt pressured to eat meat as others did. In 2005, my final year of highschool I finally became vegetarian and stuck with it. At the time I was in a long distance relationship (oh boy)…..it didn’t work. Later on May 10, 2006 I fell for Justin Sideris.....more
 
“But meat is natural, other animals do and we are meant to”
It is the position of The American Dietic Association (ADA) that appropriately planned vegetarian and vegan diets are healthful, are nutritionally adequate, and provide health benefits in the prevention and treatment of diseases.
The French naturalist Baron Cuvier stated: "Fruits, roots, and the succulent parts of vegetables appear to be the natural food of man." [1] Geoffrey Hodson quoted the great Swedish naturalist Linnaeus as follows: "Man's structure, external and internal, compared with the of other animals, shows that fruit and succulent vegetables constitute his natural food." [2] The following comparisons support these statements: [3]
1. Our small and large intestines, like those of other primates, are four times longer than those of carnivores. Because of the long intestines, meat passes very slowly through the human digestive system; it takes about 4 days during which the disease-causing products of decaying meat are in constant contact with the digestive organs (vegetarian food takes only about 1 1/2 days). [4]
2. Our hands are similar to those of apes; they are meant for picking food such as vegetables, fruits, leaves, flowers, seeds, etc., and not for tearing flesh.
3. Our lower jaw, or mandible, can move both up and down and side to side, like the primates'; carnivores' jaws move only up and down.
4. Our saliva is alkaline like that of the higher species of apes; it contains ptyalin to digest carbohydrates. Carnivores' saliva is acidic.
5. Unlike carnivores, we do not have fangs for biting into flesh. Our so-called canine teeth are not truly canine like the dog's. We are not constituted to prey upon animals, rip apart their bodies, or bite into their flesh.
6. Although our gastric secretions are acidic like that of carnivores, their stomachs have four times as much acid; this strong acidic region is necessary to digest their high-protein flesh diet.
7. Carnivores have proportionally larger kidneys and livers than we have; they need these larger organs in order to handle the excessive nitrogenous waste of a flesh diet.
8. The carnivores' livers secrete a far greater amount of bile into the gut to deal with their high-fat meat diet.
Table I (below) indicates that people are closest in structure to animals that primarily eat fruits.

But regardless of what evidence is shown, because of what we are taught in school people will always say we are naturally omnivorous, but even if we are, this means that we have a choice in our diet in terms of whether or not to eat meat. And it still leaves all the ethical arguments - compassion for animals, helping the hungry, protecting the environment - on the side of vegetarianism. Also, if we define our "natural" diet as that which is best for our health, there is abundant evidence that points to vegetarianism as our natural diet.
After a comprehensive analysis of this issue, a similar conclusion was reached by Sharon Bloyd-Pleshkin in her article, "In Search of Our Basic Diet". [6]. On the question of whether or not people are omnivores, she quotes Dr. Neal Barnard, president of the Physicians Committee for Responsible Medicine: "That depends on what you mean by `omnivore`; Does it mean what you tend to eat? Or what diet you do best on?" So, as Ms. Bloyd-Pleshkin concludes, while human beings are capable of ingesting a wide range of foods, including meat, and while they have been eating meat for the past 2 million years, "modern research shows that we do best on a diet with little or no animal protein and fat." [7]

Not convinced? Then read this lengthy article by Dr Milton R Mills entitled “The Comparative Anatomy of Eating”
The Comparative Anatomy of Eating

Humans are most often described as “omnivores.” This classification is based on the “observation” that humans generally eat a wide variety of plant and animal foods. However, culture, custom and training are confounding variables when looking at human dietary practices. Thus, “observation” is not the best technique to use when trying to identify the most “natural” diet for humans. While most humans are clearly “behavioural” omnivores, the question still remains as to whether humans are anatomically suited for a diet that includes animal as well as plant foods.

A better and more objective technique is to look at human anatomy and physiology. Mammals are anatomically and physiologically adapted to procure and consume particular kinds of diets. (It is common practice when examining fossils of extinct mammals to examine anatomical features to deduce the animal's probable diet.) Therefore, we can look at mammalian carnivores, herbivores (plant-eaters) and omnivores to see which anatomical and physiological features are associated with each kind of diet. Then we can look at human anatomy and physiology to see in which group we belong.

Oral Cavity
Carnivores have a wide mouth opening in relation to their head size. This confers obvious advantages in developing the forces used in seizing, killing and dismembering prey. Facial musculature is reduced since these muscles would hinder a wide gape, and play no part in the animal's preparation of food for swallowing. In all mammalian carnivores, the jaw joint is a simple hinge joint lying in the same plane as the teeth. This type of joint is extremely stable and acts as the pivot point for the “lever arms” formed by the upper and lower jaws. The primary muscle used for operating the jaw in carnivores is the temporalis muscle. This muscle is so massive in carnivores that it accounts for most of the bulk of the sides of the head (when you pet a dog, you are petting its temporalis muscles). The “angle” of the mandible (lower jaw) in carnivores is small. This is because the muscles (masseter and pterygoids) that attach there are of minor importance in these animals. The lower jaw of carnivores cannot move forward, and has very limited side-to-side motion. When the jaw of a carnivore closes, the blade-shaped cheek molars slide past each other to give a slicing motion that is very effective for shearing meat off bone.
The teeth of a carnivore are discretely spaced so as not to trap stringy debris. The incisors are short, pointed and prong-like and are used for grasping and shredding. The canines are greatly elongated and dagger-like for stabbing, tearing and killing prey. The molars (carnassials) are flattened and triangular with jagged edges such that they function like serrated-edged blades. Because of the hinge-type joint, when a carnivore closes its jaw, the cheek teeth come together in a back-to-front fashion giving a smooth cutting motion like the blades on a pair of shears.

The saliva of carnivorous animals does not contain digestive enzymes. When eating, a mammalian carnivore gorges itself rapidly and does not chew its food. Since proteolytic (protein-digesting) enzymes cannot be liberated in the mouth due to the danger of autodigestion (damaging the oral cavity), carnivores do not need to mix their food with saliva; they simply bite off huge chunks of meat and swallow them whole.

According to evolutionary theory, the anatomical features consistent with an herbivorous diet represent a more recently derived condition than that of the carnivore. Herbivorous mammals have well-developed facial musculature, fleshy lips, a relatively small opening into the oral cavity and a thickened, muscular tongue. The lips aid in the movement of food into the mouth and, along with the facial (cheek) musculature and tongue, assist in the chewing of food. In herbivores, the jaw joint has moved to position above the plane of the teeth. Although this type of joint is less stable than the hinge-type joint of the carnivore, it is much more mobile and allows the complex jaw motions needed when chewing plant foods. Additionally, this type of jaw joint allows the upper and lower cheek teeth to come together along the length of the jaw more or less at once when the mouth is closed in order to form grinding platforms. (This type of joint is so important to a plant-eating animal, that it is believed to have evolved at least 15 different times in various plant-eating mammalian species.) The angle of the mandible has expanded to provide a broad area of attachment for the well-developed masseter and pterygoid muscles (these are the major muscles of chewing in plant-eating animals). The temporalis muscle is small and of minor importance. The masseter and pterygoid muscles hold the mandible in a sling-like arrangement and swing the jaw from side-to-side. Accordingly, the lower jaw of plant-eating mammals has a pronounced sideways motion when eating. This lateral movement is necessary for the grinding motion of chewing.

The dentition of herbivores is quite varied depending on the kind of vegetation a particular species is adapted to eat. Although these animals differ in the types and numbers of teeth they posses, the various kinds of teeth when present, share common structural features. The incisors are broad, flattened and spade-like. Canines may be small as in horses, prominent as in hippos, pigs and some primates (these are thought to be used for defence) or absent altogether. The molars, in general, are squared and flattened on top to provide a grinding surface. The molars cannot vertically slide past one another in a shearing/slicing motion, but they do horizontally slide across one another to crush and grind. The surface features of the molars vary depending on the type of plant material the animal eats. The teeth of herbivorous animals are closely grouped so that the incisors form an efficient cropping/biting mechanism, and the upper and lower molars form extended platforms for crushing and grinding. The “walled-in” oral cavity has a lot of potential space that is realized during eating.

These animals carefully and methodically chew their food, pushing the food back and forth into the grinding teeth with the tongue and cheek muscles. This thorough process is necessary to mechanically disrupt plant cell walls in order to release the digestible intracellular contents and ensure thorough mixing of this material with their saliva. This is important because the saliva of plant-eating mammals often contains carbohydrate-digesting enzymes which begin breaking down food molecules while the food is still in the mouth.

Stomach and Small Intestine
Striking differences between carnivores and herbivores are seen in these organs. Carnivores have a capacious simple (single-chambered) stomach. The stomach volume of a carnivore represents 60-70% of the total capacity of the digestive system. Because meat is relatively easily digested, their small intestines (where absorption of food molecules takes place) are short&151; about three to five or six times the body length. Since these animals average a kill only about once a week, a large stomach volume is advantageous because it allows the animals to quickly gorge themselves when eating, taking in as much meat as possible at one time which can then be digested later while resting. Additionally, the ability of the carnivore stomach to secrete hydrochloric acid is exceptional. Carnivores are able to keep their gastric pH down around 1-2 even with food present. This is necessary to facilitate protein breakdown and to kill the abundant dangerous bacteria often found in decaying flesh foods.

Because of the relative difficulty with which various kinds of plant foods are broken down (due to large amounts of indigestible fibres), herbivores have significantly longer and in some cases, far more elaborate guts than carnivores. Herbivorous animals that consume plants containing a high proportion of cellulose must “ferment” (digest by bacterial enzyme action) their food to obtain the nutrient value. They are classified as either “ruminants” (foregut fermenters) or hindgut fermenters. The ruminants are the plant-eating animals with the celebrated multiple-chambered stomachs. Herbivorous animals that eat a diet of relatively soft vegetation do not need a multiple-chambered stomach. They typically have a simple stomach, and a long small intestine. These animals ferment the difficult-to-digest fibrous portions of their diets in their hindguts (colons). Many of these herbivores increase the sophistication and efficiency of their GI tracts by including carbohydrate-digesting enzymes in their saliva. A multiple-stomach fermentation process in an animal which consumed a diet of soft, pulpy vegetation would be energetically wasteful. Nutrients and calories would be consumed by the fermenting bacteria and protozoa before reaching the small intestine for absorption. The small intestine of plant-eating animals tends to be very long (greater than 10 times body length) to allow adequate time and space for absorption of the nutrients.

Colon
The large intestine (colon) of carnivores is simple and very short, as its only purposes are to absorb salt and water. It is approximately the same diameter as the small intestine and, consequently, has a limited capacity to function as a reservoir. The colon is short and non-pouched. The muscle is distributed throughout the wall, giving the colon a smooth cylindrical appearance. Although a bacterial population is present in the colon of carnivores, its activities are essentially putrefactive.

In herbivorous animals, the large intestine tends to be a highly specialized organ involved in water and electrolyte absorption, vitamin production and absorption, and/or fermentation of fibrous plant materials. The colons of herbivores are usually wider than their small intestine and are relatively long. In some plant-eating mammals, the colon has a pouched appearance due to the arrangement of the muscle fibres in the intestinal wall. Additionally, in some herbivores the cecum (the first section of the colon) is quite large and serves as the primary or accessory fermentation site.

What About Omnivores?
One would expect an omnivore to show anatomical features which equip it to eat both animal and plant foods. According to evolutionary theory, carnivore gut structure is more primitive than herbivorous adaptations. Thus, an omnivore might be expected to be a carnivore which shows some gastrointestinal tract adaptations to an herbivorous diet.

This is exactly the situation we find in the Bear, Raccoon and certain members of the Canine families. (This discussion will be limited to bears because they are, in general, representative of the anatomical omnivores.) Bears are classified as carnivores but are classic anatomical omnivores. Although they eat some animal foods, bears are primarily herbivorous with 70-80% of their diet comprised of plant foods. (The one exception is the Polar bear which lives in the frozen, vegetation poor arctic and feeds primarily on seal blubber.) Bears cannot digest fibrous vegetation well, and therefore, are highly selective feeders. Their diet is dominated by primarily succulent lent herbage, tubers and berries. Many scientists believe the reason bears hibernate is because their chief food (succulent vegetation) not available in the cold northern winters. (Interestingly, Polar bears hibernate during the summer months when seals are unavailable.)
In general, bears exhibit anatomical features consistent with a carnivorous diet. The jaw joint of bears is in the same plane as the molar teeth. The temporalis muscle is massive, and the angle of the mandible is small corresponding to the limited role the pterygoid and masseter muscles play in operating the jaw. The small intestine is short (less than five times body length) like that of the pure carnivores, and the colon is simple, smooth and short. The most prominent adaptation to an herbivorous diet in bears (and other “anatomical” omnivores) is the modification of their dentition. Bears retain the peg-like incisors, large canines and shearing premolars of a carnivore; but the molars have become squared with rounded cusps for crushing and grinding. Bears have not, however, adopted the flattened, blunt nails seen in most herbivores and retain the elongated, pointed claws of a carnivore.

An animal which captures, kills and eats prey must have the physical equipment which makes predation practical and efficient. Since bears include significant amounts of meat in their diet, they must retain the anatomical features that permit them to capture and kill prey animals. Hence, bears have a jaw structure, musculature and dentition which enable them to develop and apply the forces necessary to kill and dismember prey even though the majority of their diet is comprised of plant foods. Although an herbivore-style jaw joint (above the plane of the teeth) is a far more efficient joint for crushing and grinding vegetation and would potentially allow bears to exploit a wider range of plant foods in their diet, it is a much weaker joint than the hinge-style carnivore joint. The herbivore-style jaw joint is relatively easily dislocated and would not hold up well under the stresses of subduing struggling prey and/or crushing bones (nor would it allow the wide gape carnivores need). In the wild, an animal with a dislocated jaw would either soon starve to death or be eaten by something else and would, therefore, be selected against. A given species cannot adopt the weaker but more mobile and efficient herbivore-style joint until it has committed to an essentially plant-food diet test it risk jaw dislocation, death and ultimately, extinction.

What About Me?
The human gastrointestinal tract features the anatomical modifications consistent with an herbivorous diet. Humans have muscular lips and a small opening into the oral cavity. Many of the so-called “muscles of expression” are actually the muscles used in chewing. The muscular and agile tongue essential for eating, has adapted to use in speech and other things. The mandibular joint is flattened by a cartilaginous plate and is located well above the plane of the teeth. The temporalis muscle is reduced. The characteristic “square jaw” of adult males reflects the expanded angular process of the mandible and the enlarged masseter/pterygoid muscle group. The human mandible can move forward to engage the incisors, and side-to-side to crush and grind.

Human teeth are also similar to those found in other herbivores with the exception of the canines (the canines of some of the apes are elongated and are thought to be used for display and/or defence). Our teeth are rather large and usually abut against one another. The incisors are flat and spade-like, useful for peeling, snipping and biting relatively soft materials. The canines are neither serrated nor conical, but are flattened, blunt and small and function Like incisors. The premolars and molars are squarish, flattened and nodular, and used for crushing, grinding and pulping noncoarse foods.

Human saliva contains the carbohydrate-digesting enzyme, salivary amylase. This enzyme is responsible for the majority of starch digestion. The oesophagus is narrow and suited to small, soft balls of thoroughly chewed food. Eating quickly, attempting to swallow a large amount of food or swallowing fibrous and/or poorly chewed food (meat is the most frequent culprit) often results in choking in humans.

Man's stomach is single-chambered, but only moderately acidic. (Clinically, a person presenting with a gastric pH less than 4-5 when there is food in the stomach is cause for concern.) The stomach volume represents about 21-27% of the total volume of the human GI tract. The stomach serves as a mixing and storage chamber, mixing and liquefying ingested foodstuffs and regulating their entry into the small intestine. The human small intestine is long, averaging from 10 to 11 times the body length. (Our small intestine averages 22 to 30 feet in length. Human body size is measured from the top of the head to end of the spine and averages between two to three feet in length in normal-sized individuals.)

The human colon demonstrates the pouched structure peculiar to herbivores. The distensible large intestine is larger in cross-section than the small intestine, and is relatively long. Man's colon is responsible for water and electrolyte absorption and vitamin production and absorption. There is also extensive bacterial fermentation of fibrous plant materials, with the production and absorption of significant amounts of food energy (volatile short-chain fatty acids) depending upon the fibre content of the diet. The extent to which the fermentation and absorption of metabolites takes place in the human colon has only recently begun to be investigated.

In conclusion, we see that human beings have the gastrointestinal tract structure of a “committed” herbivore. Humankind does not show the mixed structural features one expects and finds in anatomical omnivores such as bears and raccoons. Thus, from comparing the gastrointestinal tract of humans to that of carnivores, herbivores and omnivores we must conclude that humankind's GI tract is designed for a purely plant-food diet.

Summary

Facial Muscles
Carnivore Reduced to allow wide mouth gape
Herbivore Well-developed
Omnivore Reduced
Human Well-developed

Jaw Type
Carnivore Angle not expanded
Herbivore Expanded angle
Omnivore Angle not expanded
Human Expanded angle

Jaw Joint Location
Carnivore On same plane as molar teeth
Herbivore Above the plane of the molars
Omnivore On same plane as molar teeth
Human Above the plane of the molars

Jaw Motion
Carnivore Shearing; minimal side-to-side motion
Herbivore No shear; good side-to-side, front-to-back
Omnivore Shearing; minimal side-to-side
Human No shear; good side-to-side, front-to-back

Major Jaw Muscles
Carnivore Temporalis
Herbivore Masseter and pterygoids
Omnivore Temporalis
Human Masseter and pterygoids

Mouth Opening vs. Head Size
Carnivore Large
Herbivore Small
Omnivore Large
Human Small

Teeth (Incisors)
Carnivore Short and pointed
Herbivore Broad, flattened and spade shaped
Omnivore Short and pointed
Human Broad, flattened and spade shaped

Teeth (Canines)
Carnivore Long, sharp and curved
Herbivore Dull and short or long (for defence), or none
Omnivore Long, sharp and curved
Human Short and blunted

Teeth (Molars)
Carnivore Sharp, jagged and blade shaped
Herbivore Flattened with cusps vs complex surface
Omnivore Sharp blades and/or flattened
Human Flattened with nodular cusps

Chewing
Carnivore None; swallows food whole
Herbivore Extensive chewing necessary
Omnivore Swallows food whole and/or simple crushing
Human Extensive chewing necessary

Saliva
Carnivore No digestive enzymes
Herbivore Carbohydrate digesting enzymes
Omnivore No digestive enzymes
Human Carbohydrate digesting enzymes

Stomach Type
Carnivore Simple
Herbivore Simple or multiple chambers
Omnivore Simple
Human Simple

Stomach Acidity
Carnivore Less than or equal to pH 1 with food in stomach
Herbivore pH 4 to 5 with food in stomach
Omnivore Less than or equal to pH 1 with food in stomach
Human pH 4 to 5 with food in stomach

Stomach Capacity
Carnivore 60% to 70% of total volume of digestive tract
Herbivore Less than 30% of total volume of digestive tract
Omnivore 60% to 70% of total volume of digestive tract
Human 21% to 27% of total volume of digestive tract

Length of Small Intestine
Carnivore 3 to 6 times body length
Herbivore 10 to more than 12 times body length
Omnivore 4 to 6 times body length
Human 10 to 11 times body length

Colon
Carnivore Simple, short and smooth
Herbivore Long, complex; may be sacculated
Omnivore Simple, short and smooth
Human Long, sacculated

Liver
Carnivore Can detoxify vitamin A
Herbivore Cannot detoxify vitamin A
Omnivore Can detoxify vitamin A
Human Cannot detoxify vitamin A

Kidney
Carnivore Extremely concentrated urine
Herbivore Moderately concentrated urine
Omnivore Extremely concentrated urine
Human Moderately concentrated urine

Nails
Carnivore Sharp claws
Herbivore Flattened nails or blunt hooves
Omnivore Sharp claws
Human Flattened nails

“But it is tasty so I should not have to give it up as the animal is dead anyway”
Load of bullshit. Animals die because of the demand meat eaters create. Taste is attainable through mock meats which are being produced more and more and taste even closer to meat. And quite frankly, when you put into perspective what animals, the environment and your body have to go through for the mere momentary enjoyment of some dead flesh, is it really worth it?

“How does it affect the environment?”
Consumption of animal products is one of the primary causes of environmental devastation, including the misuse of natural resources, pollution, global warming, and the destruction of the rain forest. Every pound of steak from feedlot-raised steers that you eat comes at the cost of 5 pounds of grain, 2500 gallons of water, the energy equivalent of a gallon of gasoline, and about twenty-five pounds of eroded topsoil. In every one of these ways, a vegetarian diet exerts less strain on our resources that does a carnivorous one. 
Plant foods are far more energy efficient than animal products. We get 2.5 calories of oats, 2 calories of potatoes, or 1.5 calories of wheat and soybeans for every calorie of fossil fuels used to grow them. the other hand, the least energy-inefficient meat production, range-land beef, requires 3 calories of fossil fuel to produce each calorie of food, while feedlot beef, the most inefficient, uses up 33 calories of fossil fuel to make one calorie of meat. Poultry, lamb, eggs, and milk production each fall somewhere between these two. This means that growing crops is at least 5 times more energy-efficient than grazing cattle, 20 times more efficient than raising chickens, and over 50 times more efficient than raising feedlot cattle! In this way, eating animal products clearly both wastes energy resources that were naturally formed over millions of years, and in the process spews pollution into the environment we live in. 
Animal agriculture also wastes water. In the U.S., more water is used to raise livestock than is consumed for all other uses put together. The amount of water needed to produce a pound of meat is fifty times that necessary to produce a pound of wheat. As Newsweek put it, "The water that goes into a 1000 pound steer would float a destroyer." As a result, underground pools of water around the world are drying up. Animal production is the major cause of falling water tables and drying wells across cattle country from west Texas to Nebraska, as the Ogalalla Aquifier, a huge underground lake that like fossil fuels took millions of years to create, is being used up to put animal products on your plate. 
In addition to wasting water, animal agriculture is the number one source of water pollution in the U.S.  After all, livestock produce 130 times as much excrement as the entire human population of the U.S., or over 126,000 pounds every second.  None of this excrement receives sewage treatment, instead it ends up polluting our streams and rivers. 
The livestock industry also wastes land. One third of North American continent is devoted to cattle grazing, and most of our cropland is devoted to producing animal feed.  It takes ten times as much land to maintain a carnivorous diet than to support a vegetarian one.  The massive amounts of pesticides used for feed crops are exempt from regulation, and end up hurting our environment.  As a result of all this, over 5 billion tons of topsoil is eroded in the U.S. every year, 85% of the country's topsoil having been destroyed by animal agriculture. 
Perhaps the most devastating environmental impact of America's carnivorous diets is deforestation.  A primary reason for the destruction of the rain forest in countries like Costa Rica, Colombia, Brazil, Malaysia, Thailand, and Indonesia, is to provide grazing land for cattle, virtually all of which goes not to the poor in these third world nations, but rather is exported to richer countries like the United States.  In fact, in the past 25 years almost half of the tropical rain forests of Central America have been razed, mostly in provide beef to North America.  The impact is enormous. It is estimated that 90% of the plant and animal species on earth live in the tropics, many still unrecorded by science. Every day more of these species are being pushed to extinction as a result of Americans' animal-centered diet.  The clearing of these forests also leads to a great deal of erosion, increases runoff which causes flooding, takes away the wood peasants often rely upon for fuel, and has been blamed for decreased rainfall. 
Animal agriculture is also a major cause of global warming, responsible for 18% of emissions, more than all the world's transportation combined. On the one hand, the earth relies upon its rain forests to cycle carbon dioxide, the primary greenhouse gas, out of the atmosphere.  The destruction of these forests for livestock production and the resulting buildup of carbon dioxide in the atmosphere is the cause of global warming.  On the other hand, livestock production worldwide is the single largest source of emissions of methane and nitrous oxide, among the most potent global warming pollutants.  By emitting greenhouse gases and destroying our rainforests, we cause climactic changes which can kill off countless species, cause widespread droughts and storms, and flood large areas of land. The dangers are many and severe, and we directly cause them every time we eat a hamburger.

“But animals are not treated badly, they’re just killed?”
Animals endure severe suffering, trauma and torture throughout their lives. Only to look forward to a painful and brutal death as their way out. If you do not think animal torture exists in Australia then please view the homepage for some links and read the subject material.

“Why is it so bad for us?”

The medical evidence is overwhelming and indisputable: The more animal foods we eat, the more heart disease, cancer, diabetes, and other degenerative disease we suffer. This has been exhaustively demonstrated beyond any doubt. If it were natural for us to eat these food, they wouldn't kill us. The fact that health can be regained by laying off meat and dairy is powerful evidence that we shouldn't have been eating those foods in the first place.
Dean Ornish, M.D. was the first person to prove that heart disease can be reversed, and he did so by feeding his patients a vegetarian diet. John McDougall, M.D. has also written extensively about how animal foods cause disease, and how people can regain their health by eating vegan instead. The esteemed T. Colin Campbell oversaw the most massive study of the relationship between diet and disease, the China Study, which the New York Times caled "the grand prix of epidemiology". His conclusions are the same as the other experts: we're not designed to eat animal foods, because we get sick when we do so.

“If we do not eat meat, where will we get our Protein?”

As long as the diet contains a variety of grains, legumes, and vegetables, protein needs are easily met.

Diets that are rich in protein, especially animal protein, are known to cause people to excrete more calcium than normal through their urine and increase the risk of osteoporosis.

Protein Requirements

With the traditional Western diet, the average American consumes about double the protein her or his body needs. Additionally, the main sources of protein consumed tend to be animal products which are also high in fat and saturated fat. Most individuals are surprised to learn that protein needs are actually much less than what they have been consuming. The Recommended Dietary Allowance (RDA) for protein for the average, sedentary adult is only 0.8 grams per kilogram of body weight

To find out your average individual need, simply perform the following calculation:

However, even this value has a large margin of safety, and the body’s true need is even lower. Protein needs are increased for women who are pregnant or breastfeeding. In addition, needs are also higher for active persons. As these groups require additional calories, increased protein needs can easily be met through larger intake of food consumed daily. Extra serving of legumes, tofu, or other high protein sources can help meet needs that go beyond the current RDA.

The Problems with High-Protein Diets

High protein diets for weight loss, disease prevention, and enhanced athletic performance have been greatly publicized over recent years. However, these diets are supported by little scientific research. Studies show that the healthiest diet is one that is high-carbohydrate, low-fat, and moderate in protein. Increased intake of whole grains, fruits, and vegetables are recommended for weight control and preventing diseases such as cancer and heart disease. High-carbohydrate, low-fat, moderate-protein diets are also recommended for optimal athletic performance. Contrary to the fad diets currently promoted by some popular books, a diet that is high in protein can actually contribute to disease and other health problems.

Osteoporosis. Diets that are rich in protein, especially animal protein,7 are known to cause people to excrete more calcium than normal through their urine and increase the risk of osteoporosis. Plant-based diets, which provide adequate protein in addition to calcium through the consumption of leafy green vegetables, beans, and fortified fruit juices, can help protect against osteoporosis.

Cancer. Although fat is the dietary substance most often singled out for increasing one’s risk for cancer, animal protein also plays a role. Specifically, certain proteins present in meat, fish, and poultry, cooked at high temperatures, especially grilling and frying, have been found to produce compounds called heterocyclic amines. These substances have been linked to various cancers including those of the colon and breast.8-10 A diet rich in whole grains, fruits, and vegetables is important in decreasing cancer risk, not to mention adding more healthful sources of protein in the diet.

Kidney Disease. When people eat too much protein, it releases nitrogen into the blood or is digested and metabolized. This places a strain on the kidneys which must expel the waste through the urine. Kidney problems may result in individuals who are susceptible to disease.

Cardiovascular Disease. Diets high in fat and saturated fat can increase one’s risk of heart disease. High-protein diets often encourage consumption of meat, eggs, and dairy products, which are all high in cholesterol, fat, and saturated fat. The most popular of the high-protein diets have been described as containing excessive amounts of these artery-clogging products. Adequate protein can be consumed through a variety of plant products which are cholesterol-free and contain only small amounts of fat.

Weight Loss Sabotage. Many individuals see almost immediate weight loss as a result of following a high-protein diet. In fact, the weight loss is not a result of consuming more protein, but by simply consuming less calories. Over the long run, consumption of this type of diet is not practical as it can result in the aforementioned health problems. As with any temporary diet, weight gain is often seen when previous eating habits are resumed. To achieve permanent weight loss while promoting optimal health, the best strategy involves lifestyle changes including a low-fat diet of grains, legumes, fruits, and vegetables combined with regular physical activity.

Protein Checklist

High protein diets are unhealthy. However, adequate but not excess amounts of protein to maintain body tissues, including muscle, are still important and can be easily achieved on a vegetarian diet. If you are uncertain about the adequacy of protein in your diet, take inventory. Although all protein needs are individual, the following guidelines can help you to meet, but not exceed, your needs.

Human performance is highest on meat-free diets

Vegetarian and vegan athletes are at the top in their sports. Carl Lewis, the runner, won nine Olympic gold medals. Lewis says that he had his best performance as an athlete after he adopted a vegan diet. (source)
The famed bodybuilder, Andreas Cahling (picture at right), is also vegan. Ditto for former Mr. USA and Mr. America, Jim Morris. (Also see Yahoo video from 2007 of Morris, now 72, who is still buff as ever and who still swears by his vegan diet.)
Ruth Heidrich, a vegan Ironman triathlete and marathon runner has racked up more than 700 first-place trophies and set several performance records. She was also named One of the 10 Fittest Women in North America.
Those who would object by saying that most top athletes eat meat can congratulate themselves for missing the point. The fact is that most Westerners are meat-eaters, because we've all grown up thinking it's good for us, and we like it. So of course most athletes are going to be meat-eaters too, since they're only human. These athletes perform well in spite of their diets, not because of them, and would undoubtedly perform even better if they ate less animal foods. And while reliable statistics are hard to come by, there is little doubt that athletes in general have been moving towards vegetarianism in large numbers over the past twenty years.
John Robbins wrote in Diet for a New America about how vegetarians have much more stamina and endurance than meat-eaters:

References

1. "Facts of Vegetarianism", North American Vegetarian Society pamphlet, (Box 72, Dolgeville, N. Y. 13329), p. 5.
2. Ibid.
3. M. M. Bhamgara, "Yoga and Diet", The Vegetarian Way, Proceedings of the 24th World Vegetarian Congress, Madras, India (1977), p. 137.
4. Barbara Parham, What`s Wrong With Eating Meat? (Denver, Colorado: Ananda Marga Publications, 1979), p. 23.

5. Dr. R. H. Wheldon, No Animal Food (New York: Heath Publishing Co.), p. 50, quoted by Nathaniel Altman, Eating for Life (Wheaton, Illinois: Theosophical Publishing House, 1977), p. 17.
6. Sharon Bloyd-Pleshkin, "In Search of Our basic Diet", Vegetarian Times, Issue 166, (June, 1991), pp. 46-55.
7. Ibid, p. 55.
American Natural Hygiene Society. The Greatest Health Discovery. Chicago: Natural Hygiene Press, 1972.
"Natural Hygiene and It`s Evolution, Past, Present, and Future." Barnard, Neal D., M. D. The Power of Your Plate - A Plan for Better Living. Summertown, Tennessee: Book Publishing Company. 1990. "Eating well for better health - 17 experts tell you how!".
Diamond, Harvey and Marilyn Diamond. Fit For Life. New York: Warner Books, 1985. Introduction to natural hygiene. Many recipes, Best selling diet and health book ever.
Diamond, Harvey and Marilyn Diamond. Fit For Life. II - Living Health. New York: Warner Books, 1987.
Esser, William, M. D. Dictionary of Natural Foods. Bridgeport, Connecticut: Natural Hygiene Press, 1983. Beautifully illustrated listing and discussion of fruits, vegetables, nuts, and seeds.
Harris, William, M. D. The Scientific Basis of Vegetarianism. Honolulu: Hawaii health Publishers, 1995. Many graphs and charts make a very strong case for the health benefits of vegetarianism.
Klaper, Michael, M. D. Vegan Nutrition: Pure and Simple.
Klaper, Michael, M. D. Pregnancy, Children, and the Vegan Diet.
McDougall, John A., M. D and Mary A McDougall. The McDougall Plan. Piscataway, New Jersey: New Century Publishers, 1983. A gold mine of information on all aspects of nutrition. Recipes.
McDougall, John A., M. D. McDougall`s Medicine - A Challenging Second Opinion. Piscataway, New Jersey: New Century Publishers, 1985. "The book that challenges the currently accepted treatments for cancer, osteoporosis, heart disease, arthritis. atherosclerosis, diabetes, and hypertension".