Photo of beans, legumes, and nuts, which are part of a healthy vegetarian diet

It’s no wonder that there has been a steady rise in the number of people identifying as vegetarians in the past decade—plant-based diets help protect against cancer, heart disease, and a number of other health problems.

More on Vegetarian Eating

But there’s a healthy way to follow a vegetarian diet and a not-so-healthy way. Sometimes when people decide to go vegan or vegetarian, they cut out meat and dairy but don’t replace them with foods that are nutritious—and as a result, they don’t improve the health quality of their diet. For instance, a 2017 study from Harvard’s T.H. Chan School of Public Health showed significantly better health outcomes for people who ate plant-based foods—such as whole grains, vegetables, and legumes—rather than, say, potatoes, refined grains, and fruit juices. And certain nutrients are easier to get from meat or dairy. For a healthy vegetarian diet, Amy Keating, R.D., a Consumer Reports nutritionist, suggests that you get enough of these four important nutrients.

1. Protein. Your body uses protein to build tissues, including muscle. The recommended amount of protein is 0.4 gram of protein per pound of body weight each day. People older than 65 may need 0.6 gram per pound because muscle mass naturally declines as we get older. For a 150-pound person, that’s 60 to 150 grams.

Meat and dairy supply a lot of protein, even in a small serving. For example, 3½ ounces of chicken breast has 31 grams. Six ounces of nonfat plain Greek yogurt has 18 grams, and one large egg has 6 grams. But there are protein-rich plant foods, too. Some examples: 4 ounces of tofu, 18 grams; 1 cup of cooked chickpeas, 15 grams; 1 cup of cooked quinoa, 8 grams; and 1 cup of cooked bulgur, 7 grams. For a healthy vegetarian diet, include a muscle-boosting protein source, such as beans, nuts, quinoa, and tofu, at every meal.

2. Calcium. This mineral helps build bone and is also important for vascular and muscle function and nerve transmission. The amount you need daily is 1,000 mg, but needs increase for men once they reach 70 and for women 50 and older. “Cut back on dairy products and your calcium intake will probably take a hit,” Keating says. Include foods such as almonds, bok choy, collard greens, kale, fortified soy or other plant milk, and "calcium set" tofu to meet your needs.

3. Iron. In its plant-based form (“nonheme”), iron isn’t absorbed as well as iron in meats (“heme”). Iron needs drop for women after menopause (men’s needs stay consistent), but getting enough can be a challenge for plant-based eaters of all ages. Pair foods containing the anemia-preventing mineral—lentils, white beans, Swiss chard—with sources of vitamin C, such as oranges and red bell peppers. Doing so helps boost iron absorption.

4. Vitamin B12. Crucial for the brain and nervous system, vitamin B12 is mainly found in animal foods such as meat, shellfish, and dairy products. “If you don’t eat dairy, look for fortified plant milks, meat alternatives, breakfast cereals, and nutritional yeast,” Keating says.

People pursuing a vegetarian diet may want to check in with their health care provider to ensure they are getting enough of the nutrients they need.