Many people think of vegetarians as one homogeneous group that just doesn't eat meat.

But nothing could be further from the truth. There are different categories of vegetarians as diverse as the reasons for going vegetarian in the first place.

A vegetarian is generally defined as someone who doesn't eat meat. But someone who is vegetarian could conceivably eat dairy products such as milk, eggs and cheese. A lacto ovo vegetarian doesn't eat meat, fish or poultry, but does consume eggs, milk or cheese. A lacto vegetarian consumes milk and cheese products, but doesn't consume eggs.

A vegan is someone who doesn't consume any animal product or by-product, including dairy food. They eat only vegetables, fruits, nuts, grains and legumes. They also don't use animal products, such as leather. Vegans also don't use white sugar because it's often processed with a substance derived from animal bones that whitens the sugar.

There are other categories within the vegetarian community. Fruitarians, for example, eat only fruit. Their rationale is that fruits, including fruits such as tomatoes, are self-perpetuating and don't need to be planted to create the food source. They consider it a way of eating that's most in balance and harmony with the earth, the most natural.

All of the above will eat cooked vegetables, fruits and legumes. There is also a growing movement towards eating only raw or living foods. This based on the assumption that cooking food processes most of the nutrients out of it, and to get all the nutritional value, vitamins and amino acids from food, it's best consumed raw, or juiced. If cooked at all, it should only be cooked to slightly over 100 degrees, so the nutrients are still retained.

The more restrictive you become with your diet, however, the more educated you need to become to be sure you're getting all the necessary proteins and vitamins that you need to maintain good health, especially muscle and heart health.

No matter what your reasons for eating a more vegetarian diet, there's no denying the obvious health benefits that are derived from the elimination of red meat from your diet. On average, vegetarians have lower levels of the blood fats, cholesterol and triglycerides than meat eaters of similar age and social status have.

High levels of blood fats are associated with an increased risk of heart disease. Lacto-ovo vegetarians, those who eat eggs and dairy products, which contain cholesterol-raising saturated fats and cholesterol, have higher cholesterol levels than do vegans, as those who abstain from all animal foods are called. But even among lacto-ovo vegetarians, cholesterol levels are generally lower than they are among meat eaters.

Researchers have found that older men who eat meat six or more times a week are twice as likely to die of heart disease as those who abstain from meat.

Among middle-aged men, meat eaters were four times more likely to suffer a fatal heart attack, according to the study. As for women, who are partly protected by their hormones and generally develop heart disease later in life than men do, the risk of fatal heart disease has been found to be lower only among the older vegetarians.

In a 1982 study of more than 10,000 vegetarians and meat eaters, British researchers found that the more meat consumed, the greater the risk of suffering a heart attack.

Though eliminating meat from the diet is likely to reduce your consumption of heart-damaging fats and cholesterol, substituting large amounts of high-fat dairy products and cholesterol-rich eggs can negate the benefit.

To glean the heart-saving benefits of vegetarianism, consumption of such foods as hard cheese, cream cheese, ice cream and eggs should be moderate. And the introduction of more vegetables, fruits and raw foods will definitely enhance the benefits of abstaining from eating meat.