Vegetarianism for many people brings to mind visions of tofu, bean sprouts and soy milk -- not very appetizing, a meat eater might think.

But there are many reasons, including health, why some individuals choose a vegetarian diet, said Elaine McDonald of the Penn State Nutrition Center, 417 E. Calder Way. A vegetarian's health benefits include lower blood cholesterol, lower blood pressure and often a diet lower in saturated fat, McDonald said.

There are five categories of vegetarian diets, McDonald said.

Vegans eat only plant foods, while ovovegetarians eat plant foods and eggs.

Lacto-ovovegetarians include dairy products, plant foods and eggs in their eating regimen.

Plant foods and fish comprise pescovegetarians' diet and pollovegetarians eat plant foods and chicken.

There are also some combinations of these, and macrobiotics, which is a philosophy of life that includes a diet without dairy and meat products, said Dorothy Blair, assistant professor of nutrition.

But a person following one of these diets must know how to get enough nutrients.

"You have to be educated about what types of food to eat to meet nutrient requirements," McDonald said.

The risks of a careless diet include iron, calcium, zinc and vitamin B-12 deficiencies, she said.

Helen Hendy, assistant professor of psychology at the University's Schuylkill Campus, agreed that a person switching to a vegetarian diet needs time to plan a healthy regimen.

"It is wanting to be healthy that motivates someone to be a vegetarian, but ironically, if it is done incorrectly it can damage their health," Hendy said.

One way a vegetarian can plan a menu is to consult with a dietician or read books on vegetarianism, McDonald said.

A healthy diet is important for health-oriented vegetarians and for people who become vegetarians for other reasons.

"Environmental vegetarians" believe that the production of meat contributes to environmental hazards such as the greenhouse effect, Blair said.

The increased number of beef cattle that are raised to feed the frowing population leads to an increased amount of methane gas in the atmosphere. Methane is a greenhouse gas.

Vegetarians might also oppose the tremendous amounts of grain and plants used to feed animals.

Animal rights supporters might become vegetarians because they oppose the treatment of animals that are raised for consumption, Blair said.

"For some it's not a total prohibition -- they might eat animals if they were raised well, humanely. But others feel we should not kill animals at all," Blair said.

Dana Giggey (junior-health policy and administration) has been a vegetarian for about five years, originally for health reasons and also now for environmental and animal rights reasons. She eliminates red meat, chicken, shellfish and dairy products from her diet.

Since becoming a vegetarian, Giggey began to learn about ecological and environmental issues.

"When you mass produce animals you use a lot of land space and natural resources. With plants you can feed a lot more people from the same space and resources," she said.

Another reason someone might become a vegetarian is because of religious reasons, she said. For instance, Muslims and Jewish people do not eat pork, while Buddhists and Brahman Hindus do not believe in killing, she said.

"Almost every major religion has some kind of prohibition against meat," Blair said.

Naveen Kumar (freshman-premedicine) began following a vegetarian diet for religious reasons during his junior year in high school. A Hindu, Kumar eliminates red meat, chicken, fish and eggs from his diet. He no longer has any urge to eat meat.

"I'm used to it by now. I don't really think about it," Kumar said.

There are also other minor reasons for becoming a vegetarian, Blair said, such as opposing "desertification" -- the overgrazing of cattle on fragile lands, especially in the Southwest -- or having concern for people in Third World nations who do not have enough to eat.

Some may believe that Third World people suffer because of a lack of grain and other plant foods, which go instead toward feeding cattle and other animals, Blair said.

The reasons for becoming a vegetarian may indicate the likelihood of staying one.

"If they stay concerned about their health, it would probably be something they might stick with," McDonald said.

But Blair believes that people who become vegetarians for moral and social reasons are much more likely to stand by it because their reasons are a cause they strongly believe in. For people who do it for health only, there is not a compelling moral reason to stick with a vegetarian diet, she said.