Andrew Weil, a medical doctor and author who writes about wellness and is the founder and director of Arizona Center for Integrative Medicine at the College of Medicine, University of Arizona, offers thoughts on the benefits and potential concerns of a vegan lifestyle. How do you define veganism? Following a vegan diet means eating only plant-based foods. Vegans refrain from eating any food derived from animals, including eggs, honey and dairy products. People who adhere to a strict vegan lifestyle also avoid buying clothing, cosmetics and other products that come from animals. What are the health benefits or downsides of being a vegan? A vegan diet can be both satisfying and healthy. Plant-based diets tend to be lower in saturated fat and cholesterol, and provide higher levels of dietary fiber, magnesium, potassium, vitamins C and E, folate, carotenoids and flavonoids. Epidemiologic data suggest that following a plant-based diet leads to lower rates of chronic disease, including a reduced incidence of heart disease, diabetes and high blood pressure. Vegans are also thinner, have lower cholesterol levels, and appear to be at reduced risk for a variety of cancers. However, vegans often have decreased intakes of vitamin B-12, calcium, vitamin D, zinc, iron and omega-3 fatty acids. Thus, I am cautious about vegan diets in general, especially for children. Following a vegan diet requires that you acknowledge the important nutrients missing from your menu options and supplement where needed. For this reason I recommend that anyone beginning a vegan diet meet first with a well-trained dietitian. What are key foods vegans should be working into their diets? Don't assume that a vegan diet is automatically a healthy one. It is just as important for vegans to reduce their intake of sweets and processed foods as it is for everyone else. I meet vegetarians who eat mostly macaroni and cheese three times a day. That's not a healthy diet. A healthy vegan diet includes a mix of raw and cooked vegetables, some fortified foods and appropriate supplementation. It is relatively easy to get adequate protein as a vegan provided that high-quality, non-animal protein source foods are eaten. Options include whole grains, seitan, legumes, vegetables, seeds, nuts and whole soy foods (soy milk, tofu, tempeh, edamame or soy nuts). Quinoa is another good option. I repeat, there is no substitute for the taking of specific supplements to help optimize health and prevent the specific nutrient deficiency states associated with following a vegan diet. That stated, consider the following: • Vitamin B-12 can be obtained from fortified breakfast cereals, fortified soy beverages and some types of brewer's yeast. • Good sources of calcium include sesame seeds, collards, kale, bok choy, broccoli, sea vegetables and calcium-fortified food and drink. You can also find calcium-set tofu. • Some cereals are fortified with vitamin D, as are soy milk and fake meats, and our bodies make significant amounts of vitamin D with exposure to sunlight. However, most adults don't get outside enough. • Good plant sources of zinc include whole grains, nuts, legumes and spinach. • Cook in iron pots and eat iron-rich foods such as dates, blackstrap molasses, whole grains, dried beans, prunes, apricots, and leafy greens. Boost absorption of iron by eating foods high in vitamin C at the same meal. • A daily handful of walnuts, or one to two tablespoons of freshly ground flaxseed per day, contributes slightly to omega-3 levels. Some vegans follow raw diets, but I find them problematic at best. People who argue in favor of raw food diets say that health-promoting enzymes are present in raw foods but are destroyed by cooking — I think that's nonsense. In fact, natural toxins present in some vegetables are broken down during the cooking process, and micronutrients such as beta carotene, lutein and lycopene are far more available to us when eating cooked rather than raw foods. What impact has veganism had on how people dine out, and how they cook for themselves? The growing number of people following vegetarian-vegan eating patterns has created a demand that farmers, restaurants and supermarkets across the country have responded to. A wider variety of satisfying, healthy food is becoming available that both meets the needs of vegans and expands the menu for omnivores.