Vegetarian diet: How to get the best nutrition

Vegetarian diets continue to increase in popularity. Reasons for following a vegetarian diet vary but include health benefits. Following a vegetarian diet may reduce the risk of heart disease, diabetes and some cancers.

But some vegetarian diets may rely too heavily on processed foods with too many calories, and too much sugar, fat and salt. These diets may not include enough fruits, vegetables, whole grains and nutrient-rich foods.

With planning, a vegetarian diet can meet the needs of people of all ages, as well as people who are pregnant or breastfeeding.

The key is to be aware of your nutritional needs so that you plan a diet that meets them.

Types of vegetarian diets

Vegetarian diets vary in what foods they include and exclude:

• Lacto-vegetarian diets exclude meat, fish, poultry and eggs, as well as foods that contain them. Dairy products, such as milk, cheese, yogurt and butter, are included.
• Ovo-vegetarian diets exclude meat, poultry, seafood and dairy products, but allow eggs.
• Lacto-ovo vegetarian diets exclude meat, fish and poultry, but allow dairy products and eggs.
• Pescatarian diets exclude meat and poultry, dairy, and eggs, but allow fish.
• Vegan diets exclude meat, poultry, fish, eggs and dairy products, as well as foods that contain these products.

Some people follow a diet that is mostly plant-based, but they still eat meat, dairy, eggs, poultry and fish on occasion or in small quantities. This is sometimes called a flexitarian diet.

Planning a healthy vegetarian diet

To get the most out of a vegetarian diet, choose a variety of healthy plant-based foods. These include whole fruits and vegetables and whole grains. Nuts and legumes, such as lentils, beans and peanuts, also are considered healthy plant-based foods.

At the same time, cut back on less healthy choices. These include sugar-sweetened beverages, fruit juices and refined grains. A registered dietitian can help you create a vegetarian plan that's right for you.

Keep in mind that the more foods you cut out of your diet, the harder it can be to get all the nutrients you need. A vegan diet, for example, cuts out natural food sources of vitamin B-12, as well as milk products, which are good sources of calcium.

To be sure that your diet provides what your body needs, pay special attention to the following nutrients:

Calcium and vitamin D

Calcium helps build and maintain strong teeth and bones. Milk and dairy foods are highest in calcium. Dark green vegetables are good plant sources if you eat enough of them. Examples include turnip and collard greens, kale and broccoli. Other options include calcium-enriched and fortified products. Calcium is added to some juices, cereals, soy milk, soy yogurt and tofu.

Vitamin D also plays an important role in bone health. Vitamin D is added to cow's milk, some brands of soy and rice milk, and some cereals and margarines. Be sure to check food labels. People who don't eat enough fortified foods and have limited sun exposure may want to talk with a health care provider about vitamin D supplements. Plant-derived vitamin D supplements are available.

Vitamin B-12

Vitamin B-12 is necessary to produce red blood cells and prevent anemia. Anemia a condition in which the body doesn't have enough healthy red blood cells to carry oxygen to all parts of the body. Vitamin B-12 is found almost exclusively in animal products, so it can be difficult to get enough B-12 on a vegan diet. Vitamin B-12 deficiency may go undetected in people who eat a vegan diet. This is because the vegan diet is rich in a vitamin called folate that can mask vitamin B-12 deficiency. For this reason, it's important for vegans to consider vitamin supplements, vitamin-enriched cereals and fortified soy products.

Protein

Protein helps keep skin, bones, muscles and organs healthy. Eggs and dairy products are good sources, and you don't need to eat large amounts to meet your protein needs. Eating a variety of plant-based foods throughout the day also can provide enough protein. Plant sources include soy products and meat substitutes, legumes, lentils, nuts, seeds, and whole grains.

Omega-3 fatty acids

Omega-3 fatty acids are found in fish, canola oil, soy oil, walnuts, ground flaxseed and soybeans. Vegetarian diets that do not include fish may be low in two types of omega-3 fatty acids called DHA and EPA. Some evidence suggests that taking in EPA and DHA omega-3 fatty acids may lower the risk for heart disease. Also, these two omega-3s may be important during pregnancy for fetal development. Research on other health effects of EPA and DHA varies. Vegetarians who do not eat fish or include sources of omega-3 fatty acids in their diet may consider adding fortified products to their diet.

Iron and zinc

Iron is important to red blood cells. Dried beans and peas, lentils, enriched cereals, whole-grain products, dark leafy green vegetables, and dried fruit are sources of iron. But the body doesn't absorb iron from plant sources as easily as animal sources. So the recommended intake of iron for vegetarians is almost double that recommended for nonvegetarians. To help your body absorb iron from plants, eat foods rich in vitamin C at the same time as you're eating iron-containing foods. Vitamin C-rich foods include peppers, strawberries, citrus fruits, tomatoes, cabbage and broccoli.

Like iron, zinc is not as easily absorbed from plant sources as it is from animal products. Fish, including crab and shrimp, are sources of zinc for pescatarians. Cheese and yogurt are sources of zinc if you eat dairy products. Plant sources include whole grains, soy products, lentils, beans, nuts and wheat germ. Zinc helps the body make proteins and grow cells. Research on zinc in the diet has found that it supports the immune system and vision, specifically.

Iodine

Thyroid hormones are made partly of iodine. Thyroid hormones help control the body's metabolism and play an important role in muscle growth. Iodine can easily be added to food by using iodized salt. Seafood and dairy also are sources of iodine. People who do not eat seafood or dairy may be at risk of iodine deficiency if they do not use iodized salt. Iodine deficiency can lead to the thyroid getting bigger as it tries to meet the body's need for thyroid hormones. When that happens to the thyroid it's called goiter. Seaweed is vegetarian option for dietary iodine.

Getting started

One way to start on a vegetarian diet is to slowly reduce the meat in your diet. At the same time, increase the amount of fruits and vegetables in your diet. Here are a few tips to help you get started:

• Ramp up. Each week increase the number of meatless meals you already enjoy, such as spaghetti with tomato sauce or vegetable stir-fry. Find ways to include greens in your daily meals. Good options include spinach, kale, Swiss chard and collards.
• Substitute. Take favorite recipes and try them without meat. For example, make vegetarian chili by leaving out the ground beef and adding an extra can of black beans. Or make fajitas using extra-firm tofu rather than chicken. You may be surprised to find that many dishes need only simple changes to become vegetarian.
• Branch out. Check the internet for vegetarian menus. Buy or borrow vegetarian cookbooks. Check out ethnic restaurants to sample new vegetarian cuisines. Adding variety to your vegetarian diet can help you meet all your nutritional needs.