Organic legumes are a cheap, easy, super-healthy way to incorporate protein into your diet.

Reducing or eliminating meat from your diet—especially factory-farmed meat that's widely available in supermarkets—not only lowers your risk of some chronic disease, it's healthy for the planet, too. A 2006 United Nations report found that the meat industry produces more greenhouse gases than all vehicles combined. But healthy vegetarians don't simply nix burgers and bacon. After all, jelly beans and french fries are technically vegetarian dishes, too, but offer virtually no nutrients. Vegetables and whole grains are not only nutrient-rich, they can be great
non-meat protein sources for vegetarians.

The key is to mix different vegetarian protein sources into your daily routine, and eat enough whole grains to insure you're getting enough amino acids. Your immune system will thank you, too, especially during flu season! "Protein not only builds muscle and maintains organ structures, but is also needed to mount prompt, strong immune responses," explains Carol S. Johnston, PhD, RD, professor and director of the nutrition program at Arizona State University's College of Nursing and Health Innovation. "You never know when you will be exposed to viruses or other infectious agents, so you want to have adequate protein intake daily to have amino acids ready for immune protein synthesis at the time of infection."

Here's what you need to know about protein sources for vegetarians:

• Know how much you need. The average 150-pound person needs 55 to 68 grams of protein a day, or about 20 grams of protein per meal. To put this into perspective, dairy generally contains about 8 grams per serving, while an ounce of nuts or seeds, or an egg white, boast 6 grams each. A half cup of legumes, such as cooked beans or lentils, contains about 10 grams, making them an important protein sources for vegans. Even grains and vegetables generally have a gram or two of protein.

• Figure out what you are. Lacto/ovo vegetarians eat eggs and dairy foods, two high-quality protein sources, meaning a little goes a long way towards meeting protein and amino acid requirements, explains Johnston. If you fit this bill, shoot for three to four servings of low-fat or nonfat dairy a day, including yogurt, milk, and cheese. Vegans, who avoid all animal-source food, need to pay closer attention and make use of the vegetarian protein sources listed below.

• Make planning a priority. When people switch over to eating meat-free, "a lot don't realize that when you eliminate big food groups, it may be more challenging to get certain nutrients," explains Joan Salge Blake, RD, author of Nutrition and You. Planning is a must for healthy vegetarians, and some people even sit down with a registered dietician to learn how to personalize vegetarian meal plans.

All plant foods are lower in one or another essential amino acids—the building blocks of protein—than animal foods. To remedy this, combine whole grains and legumes in the same day's meal plan (not necessarily the same meal). The amino acid combo in those foods is the reason rice and beans, for example, are such important protein sources for vegetarians. "Any whole grain like quinoa, corn, whole wheat, buckwheat, brown rice, plus a legume like pinto, lentils, black beans, and garbanzos is perfect," explains spokeswoman Cristine Gerbstadt, MD, RD. "Think of hummus and whole wheat pita, whole wheat pasta and red beans, brown rice and curried lentils, peanut butter on multi whole grain bread." If you're looking to lose weight, she says to shoot for three ½-cup servings of whole grain products a day. If you're superactive, you may want to eat six servings a day.

• Unlock iron; avoid B12 deficiency. Since just 10 percent or less of the iron in plants is absorbed in your gut, consider drinking a glass of orange or tomato juice at the same meal as high-iron foods such as beans. The vitamin C helps unlock the iron from the plants.