The answers you have received from other devotees on this question are spiritual answers. All Vedic regulations have real scientific reasons behind them which we may not appreciate upfront. But if deep study is made, then these reasons will show up. In other words even materially speaking it is not good for individuals as well as humanity, leave alone the bad karma part.
On this subject I am providing more information on advantages of vegetarianism to humanity compiled from various sources available on the internet.
So you have the material reasons also to convince you.
Anatomy of various species:-
The Environmental reasons:-
1. Conservation of Fossil fuel. It takes 78 calories of fossil fuel to produce 1 calorie of beef protein; 35 calories for 1 calorie of pork; 22 calories for 1 of poultry; but just 1 calorie of fossil fuel for 1 calorie of soybeans. By eating plant foods instead of animal foods, I help conserve our non-renewable sources of energy.
2. Water Conservation. It takes 3 to 15 times as much water to produce animal protein as it does plant protein. As a vegetarian I contribute to water conservation.
3. Efficient use of grains. It takes up to 16 pounds of soybeans and grains to produce 1 lb. of beef and 3 to 6 lbs. to produce 1 lb of turkey & egg. By eating grain foods directly, I make the food supply more efficient & that contributes to the environment.
4. Soil conservation. When grains & legumes are used more efficiently, our precious topsoil is automatically made more efficient in its use. We use less agricultural resources to provide for the same number of people.
5. Saving our forests. Tropical forests in Brazil and other tropical regions are destroyed daily, in part, to create more acreage to raise livestock. By not supporting the meat industry, I directly reduce the demand to pillage these irreplaceable treasures of nature. Since the forest land "filters" our air supply and contains botanical sources for new medicines, this destruction is irreversible.
6. Aesthetics. Decaying animal parts, whether in a freezer case or served in restaurants, can never be as aesthetically pleasing to the senses as the same foods made from wholesome vegetable sources. Only habit can allow one not to perceive this: a change in diet makes this self-evident.
Personal Health reasons:-
1. No deficiencies. There is no nutrient necessary for optimal human functioning which cannot be obtained from plant food.
2. High fat plus cholesterol. Animal foods are higher in fat than most plant foods, particularly saturated fats. Plants do not contain cholesterol.
3. "Carb" deficient. Meat is deficient in carbohydrates, particularly the starches which are so essential to proper health.
4. Vitamin deficient. Except for the B-Complex, meat is largely deficient in vitamins.
5. Agricultural Chemicals. Being higher on the food chain, animal foods contain far higher concentrations of agricultural chemicals than plant foods, including pesticides, herbicides, etc.
6. Exposure to livestock drugs. There are over 20,000 different drugs, including steroids, antibiotics, growth hormones and other veterinary drugs that are given to livestock animals. These drugs are consumed when animal foods are consumed. The dangers herein, in secondary consumption of antibiotics, are well documented.
7. Pathogenic Microorganisms. There are a host of bacteria and viruses, some quite dangerous, that are common to animals. When I eat meat, I eat the organisms in the meat. Micro-organisms are present in plant foods too, but their number and danger to human health is by no means comparable to that of those in meat.
8. Worms and other Parasites. Ditto on # 13!
9. Shelf life differential. Plant foods last longer than animal foods. Try this experiment: Leave out a head of lettuce and a pound of hamburger for 1 day, which will make you sick?
10. Organoleptic Indications of Pathogens. Plant foods give tell-tale signs of "going bad". Ever hear of someone getting sick from "bad broccoli"?
11. Heart Disease. Meat eating increases the risk of heart disease, this country's #1 killer. The correlation is an epidemiological fact.
12. Cancer prevention. Of all the natural cancer prevention substances found: vitamin C, B-17, hydroquinone, beta carotene, NDGA – none has been found to be animal derived. Yet most meats, when cooked, produce an array of benzenes and other carcinogenic compounds. Cancer is infinitely easier to prevent than cure. Soybeans contain protease inhibitor, a powerful anticancer compound. You won't find it in useful quantities in animal based food.
13. Disease Inducing. The correlation between meat consumption and a wide range of degenerative diseases is well founded and includes…..
15. Kidney Stones and Gallstones
17. Multiple Sclerosis
19. Gum disease
20. Acne. Aggravated by animal food.
21. Obesity. Studies confirm that vegetarians tend to be thinner than meat eaters. Obesity is considered by doctors to be a disease within itself.
22. Intestinal Toxemia. The condition of the intestinal flora is critical to overall health. Animal products putrefy the colon.
23. Transit time. Wholesome food travels quickly through the "G.I" tract, leaving little time to spoil and incite disease within the body.
24. Fiber deficient. Fiber absorbs unwanted, excess fats; cleans the intestines; provides bulk and aids in peristalsis. Plant food is high in fiber content; meat, poultry and dairy products have none.
25. Body wastes. Food from animals contain their waste, including adrenaline, uric and lactic acid, etc. Before adding ketchup, the biggest contributors to the "flavor profile" of a hamburger are the leftover blood and urine.
26. Excess protein. The average American eats 400% of the RDA for protein. This causes excess nitrogen in the blood that creates a host of long-term health problems.
27. Longevity. To increase one’s risk of getting degenerative disease means decreasing one’s chance to live a naturally long healthy life. Huzas and other peoples with large centenarian populations maintain lifestyles that are relatively meat free.