The idea of food as a lifestyle decision is growing. People go fat-free, carb-free, dairy-free, and gluten-free; they go organic, Kosher, or join the slow food movement. There are many reasons people choose dietary restrictions – to promote good health, to fend off bad health, to help the environment, for ethical or religious reasons, and even purely out of habit or family history.

Vegetarianism and veganism have been around for centuries, particularly in certain cultures and/or religions, and the reasons for committing to these lifestyles are enormously varied.

Vegetarians consume no animal flesh; lacto-ovo vegetarians consume both dairy products and eggs, ovo-vegetarians consume only eggs; and lacto-vegetarians eat only dairy products... The vegan lifestyle is more restrictive.

Vegetarians consume no animal flesh – red meat, poultry, and seafood are avoided – but they may consume other animal products, depending on personal preference. For example, lacto-ovo vegetarians consume both dairy products and eggs, ovo-vegetarians consume only eggs, and lacto-vegetarians eat only dairy products.

The vegan lifestyle is more restrictive. It typically avoids animal products of any kind – vegans stay away from meat, fish, dairy, eggs, and honey as well as other products that you might not think of, like gelatin, silk, and wool clothing.

Years ago the word “vegan” was virtually unheard of, but lately celebrity vegans like Bill Clinton, Mike Tyson, Paul McCartney, Alicia Silverstone, Natalie Portman, and Ellen Degeneres are raising its profile. The result is that more and more people are following in the footsteps of Leonardo da Vinci, Mohandas Gandhi, and Albert Einstein and choosing a vegetarian or vegan diet.

Health is a major factor in the shift to a diet with few or no animal products. People who worry about obesity and high cholesterol simply have to look at the role animal fats play in their diets. But ethical concerns about animal welfare, food safety and the antibiotic resistance fostered by feedlots are also making a vegetarian or vegan diet more attractive.

The Health Benefits and Drawbacks of the Veggie Life

What are the demonstrated health benefits of being vegetarian or vegan? Most people are aware of the advantages of cutting down on red meat or perhaps reducing one’s whole milk intake – but is it really necessary to make a full-fledged lifestyle change? In the same vein, what are the drawbacks or risks associated with vegetarianism/veganism?

Being vegetarian (or even vegan) doesn’t mean you’re automatically healthier. After all, you can still have a baked potato loaded with butter, sour cream, and cheddar cheese – simply leaving off the bacon doesn’t make the meal healthy!

To help us tackle all of the important issues, we turned to Marion Nestle, PhD, MPH, professor in the Department of Nutrition, Food Studies, and Public Health at NYU and author of the blog, Food Politics; and David Katz, MD, MPH, Director, Yale University Prevention Research Center. We also polled some of our readers on how their vegetarian/vegan diets work for them.

The Pros: Reducing Risk, Lengthening Life
Vegetarian and vegan diets are linked to a growing number of significant and well-documented health benefits, according to both of our experts, and to the latest research. Dr. Katz asserts that “plant-based eating, done well, is associated with reduced risk of all chronic disease, and more vitality. Specifically, the literature suggests reduced risk of cancer, heart disease, diabetes, stroke, obesity. An optimal, plant-based diet is very powerful medicine indeed.”

Studies have found that vegetarian diets are associated with lower body mass index (BMI), and they have even been discussed as a primary means of preventing heart disease. Vegetarian diets, particularly those that are low-fat and high-fiber, may also shift the makeup of bacteria in the gut which are so crucial to our colon health and overall health. There may be cognitive benefits as well. Some studies have even shown vegetarianism to be linked to reduced risk of dementia than people who eat meat.

The official position of the American Dietetic Association is that vegetarian diets can be a healthy option for people in all walks of life – adulthood, childhood, infancy, pregnancy – if they are well-designed and include all of the essential vitamins and nutrients.

Bill Clinton famously went vegan (or mostly so) a few years back to address his declining heart health. Having had multiple heart surgeries to unblock the buildup in the blood vessels around his heart, his most recent surgery was apparently what prompted him to make a change once and for all.

The official position of the American Dietetic Association is that vegetarian diets can be a healthy option for people in all walks of life – adulthood, childhood, infancy, pregnancy – if they are well-designed and include all of the essential vitamins and nutrients.

He told Sanjay Gupta of CNN, “I essentially concluded that I had played Russian roulette, because even though I had changed my diet some and cut down on the caloric total of my ingestion and cut back on much of the cholesterol in the food I was eating, I still — without any scientific basis to support what I did — was taking in a lot of extra cholesterol without knowing if my body would produce enough of the enzyme to support it, and clearly it didn’t or I wouldn’t have had that blockage. So that’s when I made a decision to really change.”

Now, he says, “I like the vegetables, the fruits, the beans, the stuff I eat now.” And even better, he tells Gupta, "All my blood tests are good, and my vital signs are good, and I feel good, and I also have, believe it or not, more energy.” The public has certainly been aware of Clinton’s changing physique in recent months.

Dr. Katz agrees that the vegetarian and vegan diets can indeed lead to “more years in life, and more life in years.” In other words, not only do they appear to lengthen life, but like Bill Clinton, many people report feeling better and having more energy when consuming a healthier, low-fat, plant-based diet. In the same vein, one reader we talked to told us, “Within the first month of giving up meat, I felt better than I ever did! The heavy feeling in my lower abdomen was gone, I felt light. As time went on, my skin also cleared, had more energy, woke up mentally more alert, and just overall felt better.”

The Cons: Nutrient Deficiencies and Poor Diet
While plant-based diets offer significant benefits to one’s health, the few risks they come with should be mentioned. Dr. Nestle mentions the essential nutrients that may be lacking partially or completely with strict vegetarian/vegan diets.

“The health benefits of vegetarian diets depend on how they are defined,” she says. "Vegans must find an alternative source of vitamin B12.” Vitamin B12 is found solely in animal products like meat, fish, dairy, and eggs. Although it can also be found in some algae, there is debate as to whether this form of B12 is “bioavailable,” meaning that our bodies may not absorb it adequately. Even more, research has found that vegans may be deficient in vitamin B12 and omega-3 fatty acids, both essential to the normal functioning of the body and brain. Strict vegans are typically advised by their doctors to take supplements, but which supplements one needs to take will depend on one’s specific diet, the length of time one has been vegan, and the body’s specific nutritional needs..

Vitamin D may also be a problem, Dr. Katz says, because vegans don’t consume vitamin D-fortified dairy products. Studies have found that vegetarians lack the vitamin, which is crucial for bone health. Vitamin-D deficiency raises the risk of osteoporosis. While vitamin deficiencies of any kind may take years to develop, they can be serious.

'The health benefits of vegetarian diets depend on how they are defined,' Nestle says. 'Vegans must find an alternative source of vitamin B12.'

Vitamins play critical roles in fundamental cell processes, so their deficiencies can lead to problems in cell functioning, both in the organs of the body and in the brain. Symptoms of deficiencies can include dizziness, fatigue, shortness of breath, anemia, poor concentration, problems learning and remembering, and increased risk of cognitive decline as we age. It is therefore important to talk to your doctor if you might be at risk.

Strict veganism can also lead to not getting enough complete protein. Also known as “high quality protein,” complete protein includes all of the 10 essential amino acids that the body cannot make on its own. Since there are limited sources of single plant-based foods that provide all the essential amino acids (soy and quinoa are two), it is often necessary to pair foods together to get the complete range. This is why rice and beans, as well as other pairings like peanut butter and rice cakes, are popular protein sources among vegans.

Meat-Free Does Not Always Mean Healthy
Dr. Katz raises a final point to bear in mind: being vegetarian (or even vegan) doesn’t mean you’re automatically healthier. After all, you can still have a baked potato loaded with butter, sour cream, and cheddar cheese – simply leaving off the bacon doesn’t make the meal healthy! Even if you’re vegan, you could theoretically live on Oreos and french fries – so it’s all a matter of how you do it. As Katz puts it, “the devil is always in the details. Sugar is ‘vegan.’ It is certainly possible to have a very poor vegetarian or vegan diet.”

For this reason, the best advice may be to strike a balance. By eating a mostly plant-based diet, with a few exceptions, you can then reap the many benefits of vegetarianism/veganism that promote health and longevity, while still making sure to consume the essential nutrients that are missing from a true vegan diet.

Katz says that a drawback of veganism is that “some healthful foods are omitted, such as fish. It may be that a diet that includes fish is better for health than one that excludes it.” It is important to keep in mind the specific needs of your body, including the number of calories, proteins, and carbs it needs; the amount of activity you engage in; your age, weight, and particular vitamin requirements. Always talk to your doctor before making any major nutritional changes.

There’s More to the Picture than Health Alone

While the health benefits of vegetarianism, or even partial vegetarianism, are clear, there are reasons other than health that prompt a person to go veggie. Reduced food costs, the betterment of the environment and global food supply, and the well-being of animals can all motivate people to reduce or give up meat. Here we’ll discuss, along with our experts and vegetarians who responded to postings on VeggieBoards, several the other considerations that go into eating more plants than animals.

The Cost of Meat
“Why buy the cow when you can eat his grain instead?” is a familiar vegetarian refrain. The costs associated with feeding animals used for food and dairy are relatively high, compared to other methods of producing high-quality protein. Aside from feed prices, it also costs money to house food animals, vaccinate them, and provide antibiotics and hormones if they are used.

Meat costs roughly 25% more per gram to produce than alternative proteins.

Less expensive, say experts, is cultivating and harvesting beans, lentils, corn, and rice. As Dr. Katz underlines, “Lentils and beans are far cheaper sources of high-quality protein than meat.” One vegetarian wrote that she definitely felt the difference in her pocketbook after going vegan, which allowed her to spend the money in other ways that were important to her: “Alternate proteins are so much cheaper than meats, I can afford to buy more organics.”

Meat costs roughly 25% more per gram to produce than alternative proteins. The authors of this study point out that according to some activists, food animal production “is often seen as a food factory in reverse, consuming more energy than it produces.” If more people switched to non-animal sources of protein, the theory goes, the money spent on producing and maintaining food animals could be applied to cultivating crops to feed hungry people instead.

Dr. Nestle tell us that “raising fewer farm animals would be much less resource-intensive and better for people and the planet” (more on the planet below). It might be worth doing your own experiment: try substituting rice and beans in for meat a couple of times a week, and see what kind of difference it makes in your wallet.

Environmental and Epidemiological Considerations
In addition to the high financial cost involved in raising meat and poultry for food, there are also environmental costs. The discussion can get complicated because the resources required in raising food animals are both economic and environmental, and both factors are important to people who choose the vegetarian or vegan lifestyle.

Factory farms generate a lot of animal waste (feces and urine) and as a result, large amounts of chemicals can be produced, including methane gas and ammonia. Animal waste is stored in containers, according to the National Resources Defense Council (NRDC), and can be deadly to the surrounding environment, particularly if the “waste lagoons” leach or leak into the soil.

Proteins like lentils and soy represent a fraction of the carbon footprint of beef, cheese, and pork.

A recent FDA investigation found terrible conditions at egg farms, in which large uncontained piles of chicken feces were tainted with salmonella and possibly linked to the rash of egg-related salmonella outbreaks in the U.S. (more on this below). The problem of how to get rid of animal waste without contaminating the surrounding environment and wildlife is one that policy makers and advocates have yet to solve.

Advocates say that aside from the contamination issues associated with factory farms, the environmental resources required to produce meat and dairy products increases our carbon footprint considerably. The massive amount of fertile land required to produce the food animals raised for food eat, along with the emissions from farms, processing plants, transportation, and waste disposal, put significant pressure on the environment and surrounding wildlife.

The Environmental Working Group recently published a study showing the difference in environmental impact for various sources of protein, from beans to beef. They found that proteins like lentils and soy represent a fraction of the carbon footprint of beef, cheese, and pork.

Chicken and turkey are the better choices of the meats. The EWS also calculates, for example, that if a four-person family did not eat meat or cheese for one day a week, it would be the environmental equivalent off “taking your car off the road for 5 weeks or shortening everyone’s daily shower by 3 minutes.” Taking it a step further, if everyone in the U.S. skipped meat and cheese for one day a week, they say, it would be like removing 7.6 million cars from the roads or not driving 91 billion miles.

Dr. Katz sheds light on the same point: “If most would eat mostly plants, we might manage to eat some animals without harming the planet.” In other words, any amount of plant-rather-than-meat-eating you do is good for the environment; and the more, the better.

Finally, the proliferation of factory farms and the growth of their physical size are intimately tied to the rise in foodborne illness in this country and across the world. In addition to contaminated meat, the runoff from farms – particularly bacteria-containing feces – can pollute vegetable farms in surrounding areas.

Dr. Nestle, among others, suggests that the cross-contamination of vegetables from meat farms could be linked to the rise in outbreaks in the U.S. and abroad. Dr. Katz and Dr. Nestle both agree that the widespread practice of vegetarianism/veganism could help reduce foodborne infection significantly. Short of reducing our reliance on meat for a source of protein, re-conceiving how we practice large-scale farming in this country would certainly be a wise maneuver.

Ethical-Political Reasons
Large scale farming is also responsible for the often terrible conditions in which animals are housed and prepared for slaughter. And it is this ethical concern for the animals that is clearly a driving force for many who are vegetarian/vegan. While some feel may feel uncomfortable eating animals because they consider themselves “animal people,” others may wish to take it a step further and refrain from any animal product so as not to partake in an industry they do not wish to support. In this way, being vegetarian or vegan is much more than a dietary choice – it is a lifestyle choice, or, for some, a political statement.

As more people have become aware of the problems and shortcomings in how food animals, dairy cows, and egg-laying chickens are handled these days, more are demanding better of the practices.

One reader tells us, “It was easy for me to be lacto-vegetarian. But I knew I had to go vegan to live my beliefs.” She says the transition had its difficulties, psychologically, since it’s easy to forget that dairy products also come from farm animals: “Giving up cheese and milk and egg ingredients wasn't so easy. The disconnect of dairy is much more insidious than actual flesh. It's been about 1 1/2 years of vegan, and while I've had slips along the way, it's getting much easier.”

As more people have become aware of the problems and shortcomings in how food animals, dairy cows, and egg-laying chickens are handled these days, more are demanding better of the practices. “Humanely-raised,” “ethically-raised,” or “humanely-handled” animals are becoming more common labels on food labels these days and at restaurants. Stores like Whole Foods have made offering meat products from ethically handled animals part of their business model. The more the public demands it, and expresses it be decided where to put their money, the more practices will change.

What Are We Cut out to Eat?

Some people argue that our natural state simply isn’t vegetarianism or veganism, evolutionarily speaking, since our closest ancestors are meat-eaters, and since there are some essential nutrients that we just can’t get in places besides animal products.  Dr. Katz addresses the question by underlining the fact that it’s really a gray area – but we can go either way, provided that we do it conscientiously. “We are, biologically, omnivores. Our closest cousins – chimps – are also omnivores, but do fine eating only plants. We, too, can do fine eating only plants. So yes, we are ‘cut out’ for veganism, but we are also cut out for a mixed diet.”

'My dietary mantra is eat less,move more, eat plenty of vegetables, fruits, and whole grains, don’t eat too much junk food, and enjoy what you eat!'

Regarding the decision of being vegetarian or vegan, Dr. Katz says that it simply may not be worth quibbling over when all is said and done. “For our own health,” he says, “we don’t know whether an optimal all-plant or optimal mostly-plant diet is better, and the difference may not matter much. The theme of healthful eating is very clear and decisive; there are almost certainly comparably good variations on that theme.” Dr. Katz adds that “clearly, though, eating mostly plants is advisable either way – and essential for the well-being of the planet, now that there are 7 billion of us!”

Dr. Nestle agrees that one need not be a stickler 100% of the time, as long as your diet is, on average, well thought-out, and you indulge only modestly. “My dietary mantra is eat less,” she says, “move more, eat plenty of vegetables, fruits, and whole grains, don’t eat too much junk food, and enjoy what you eat!”

The arguments for being a vegetarian or vegan are compelling and many are convincing, for reasons involving our health, the planet, its people, the immediate environment, and the well-being of the animals we use for food, milk, and eggs. The health benefits of both diets are virtually inarguable, though it’s crucial to track your vitamin levels with your doctor if you are vegan.

The message of both experts is that it’s probably not necessary to do either diet 100% of the time: Do what you can do. You can still reap the many benefits by simply eating more plants, fruits, and whole grains, while reducing your intake of meats and dairy as you can. Whatever diet one arrives at, choosing your foods with care and attention to where they come from will be in the best interests of your own health, the planet, and the animals that provide them.