Arguments for vegetarianism are strong in all aspects from HEALTH, ECOLOGY, ECONOMICAL and SPIRITUAL perspectives.
HEALTH
Human teeth are designed for grinding and chewing vegetable matter (like herbivores).
Humans lack sharp front teeth characterizing of carnivores - they swallow food without chewing and so don't need molars or jaws that can move sideways.
To digest meat, stomach must contain digestive juices high in hydrochloric acid but humans and herbivores have this less than 1/20 the strength of carnivores.
As meat is corpse, it produces poisonous waste as it goes through the body, so it must be eliminated fast. Carnivores do this with an alimentary canal 3 times their body length. Human alimentary canals are 12 times body length allowing more toxic effects in the body.
The kidneys extract waste from the body and so must work tree times harder for flesh-eaters than for vegetarians. Youth can do this, but for older people it's more of a strain causing risk of kidney disease or failure.
Natural flesh eaters can metabolize large amounts of animal fats and cholesterol. Humans cannot. The imbalance excess creates fatty deposits clogging the arteries, called atherosclerosis. This blocks flow of blood increasing chance of heart disease, heart attacks, strokes and blood clots.
Cancer can be caused by high-fat low-fiber diet, which meat-centered diet tends to produce. As meat goes through colon, it releases poisons called carcinogens (cancer producing) properties.
Chemical preservatives in meat can react with certain chemicals found in beer, wine, tea, tobacco, creating NITROSAMINES which are cancer producing.
Animals are fattened by hormones, tranquilizers, antibiotics, and over 2000 other drugs. They are still present in flesh when eaten, though there is no law saying they must be declared on the label.
Sodium nitrate and nitrite are used to slow down decay of flesh, making meat seem bright and reddish, but without them, it would be gray/green and repelling to customers.
The pain to animals being slaughter produces pain poisons, which enter into the flesh (urea and uric acid) which further poison the flesh.
NUTRITION
Often meat eaters feel vegetarianism means lack of protein but the eight of the 22 essential amino acids that are needed by the body, which came from protein, can be found in abundance in non flesh like: DAIRY PRODUCTS, GRAINS, BEANS, and NUTS. Cheese, peanuts, lentils for example, contains more protein per ounce than hamburger, pork or steak.
Some studies have found that both vegetarians and meat eaters take in more than twice the amount of protein needed. It can't be used by the body and so becomes NITROGENOUS WASTE burdening the kidneys and reducing body energy capacity.
Proper vegetarianism also gives more nutritional energy than meat: A Brussels University study by Dr. Iotekyo and V. Kipani showed vegetarians could perform physical tests 2 to 3 times longer than flesh eaters before exhaustion, and fully recovered from tiredness in 1/5 of time for meat eaters.
HIDDEN COST OF MEAT
In terms of calories per acre, a diet of grains, vegetables and beans will support 20 times more people than a meat diet.
Using grain to feed animals for meat is very wasteful: for every 16 pounds of grain, you get 1 pound of flesh.
A report to the United Nations world food conference stated that: "The over consumption of meat by the rich means hunger to the poor".
Some ecologist found that 1 pound of wheat growth requires 60 pounds of water while 1 pound of flesh requires 2.500 to 6000 pounds of water.
DO UNTO OTHER
Slaughterhouses contain screaming animals that are subdued by electric shock, concussion gun or hammer blow.
They are placed on conveyor belts and have their throat cut while on conveyor belt.
Pythagoras was vegetarian (and would pay fisher men to throw fish back into river).
Advocates of vegetarianism included Benjamin Franklin, Adam Smith, Shelley and Leo Tolstoy.