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SUNY Downstate Health Sciences University

Committee on Plant-Based Health & Nutrition

Nutrients and Food Categories FAQ

Can I get enough protein on a plant-based diet?

Absolutely. Some terrific plant-based protein sources include legumes (lentils, chickpeas, black beans), starchy vegetables (potatoes), leafy green vegetables (kale, spinach), whole grain products (breads, pasta), nuts, and seeds. Soy products (tofu, tempeh, and edamame) are among the richest sources of protein and nearly all research studies show positive health benefits of soy with no significant risks. In the past many experts advocated for combining foods with different types of protein (e.g., rice and beans) to get the full benefits, but we now know that “protein combining” is not necessary.

Are animal proteins better than plant proteins?

No, both plants and animals can be excellent sources of protein. Any whole food, plant-based diet with a good variety of protein-rich foods (see preceding question) will provide all the amino acids (protein building blocks) your body needs without having to use any supplements. Animal products are also naturally high in protein but are associated with chronic disease and some cancers (colon, rectal, prostate, and prostate). The World Health Organization classifies processed meats (cured, salted, fermented, or smoked) as definitely cancer-causing in humans and further classifies all red meats (beef, veal, pork, lamb, mutton, goat) as probably cancer-causing.

How do I get enough calcium on a plant-based diet?

By eating calcium-rich foods including almonds, black beans, tofu (if calcium fortified), leafy green vegetables (broccoli and kale, collard, turnip, or mustard greens), and sweet potatoes. There are also many calcium-fortified foods such as breakfast cereals, and plant milks made from soy, rice, oats, cashews, or almonds. Vitamin D is needed for your body to use calcium, because without vitamin D only a small amount of calcium is absorbed. Sun exposure for 5 to 15 minutes is the best natural source of vitamin D, but people with dark skin or in colder climates will need to use supplements or fortified foods (breakfast cereals, bread, plant-based milks).

How can I get omega-3 fatty acids from a plant-based diet?

Omega-3 fatty acids, which occur in high levels in fish oils and fatty fish, may lower heart disease risk, reduce depression, and improve brain function. People who do not eat fish can get enough omega-3 fatty acids, without the need for supplements, by adding a few foods rich in omega-3 fatty acids to their diet. The best plant-based sources of omega-3 fatty acids are ground flaxseeds, chia seeds, hemp hearts, brussels sprouts, walnuts, and wheat germ. And you don’t need much to meet daily requirements; one or two tablespoons of chia seeds, hemp hearts, or ground flaxseed should suffice.

Do I need a vitamin B12 supplement if I am on a plant-based diet?

Yes, because B12 is the only vitamin not reliably supplied by a whole food, plant-based diet. Although some plant-based foods (soy products, breakfast cereals, and plant milks) are fortified with B12, it is best to also use a daily or weekly B12 supplement (depending on concentration) to avoid problems associated with B12 vitamin deficiency (low blood count, nervous system damage, and heart disease). Meat eaters generally do not need supplements, because animals that eat plants absorb the B12 produced by bacteria in their own stomach and intestines.

Can I get enough iron from a plant-based diet?

You can get all the iron you need from a plant-based diet. The best plant-based sources of iron include spinach, lentils, chickpeas, beans, tofu, cashew nuts, chia seeds, hemp seeds, pumpkin seeds, kale, quinoa, fortified breakfast cereal, and dried apricots, figs, and raisins. Your body absorbs iron best when vitamin C is available, which is found in bell peppers, broccoli, cabbage, brussels sprouts, and citrus fruits. Studies show that people who eat plant-based diets actually tend to get more iron than meat eaters and that consuming dairy products can significantly reduce iron absorption.

Will eating carbohydrates cause me to gain weight?

Not if you eat healthy whole food, complex carbohydrates. Foods that are rich in complex carbohydrates can help with weight control, because they contain less than half the calories of fat, which means that replacing fatty foods with carbohydrates cuts calories. Healthy carbohydrates come from fruits, vegetables and whole-grain products, which contain fiber and other nutrients that help you feel full longer. In contrast, unhealthy carbohydrates – pastries, soft drinks, juices, and refined flour products (white bread, bagels, crackers, cereals, cookies, and pasta) – are quickly converted to glucose (sugar) in the blood, leading to energy spikes and insulin resistance (reduced ability of your body’s cells to absorb and use glucose). The result is weight gain, which is worse when accompanied by high fat consumption that further promotes insulin resistance.


How is this FAQ list different from others?

A simple web search of FAQs for plant-based diets has hundreds of results, so why another list? Because much of what exists if full of inflated claims, biased opinions, and research that is applied selectively or based on animal studies. Instead, we strive for an evidence-based, practical guide that cuts through the hype and tells what you really need to know. The material has been reviewed by experts in medicine, nursing, nutrition, public health, medical education, community wellness, health policy, and health disparities.


For questions or comments regarding this document, please contact Richard Rosenfeld, MD, MPH, MBA, Chair of the SUNY Downstate Committee on Plant-based Health & Nutrition at


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