Dietitians debunk 8 vegan diet myths even longtime vegans believe

You might have ditched meat, committed to eating plant-based meals even when dining out, and make a habit of reading every label at the grocery store. However, nutrition experts say even the most committed vegans are getting some things surprisingly wrong.

As a vegan myself, I was intrigued by what I learned from interviewing two registered dietitians Vanessa Rissetto and Stephanie Gomez about the misconceptions they encounter most often in their practices. What they shared might surprise even the most seasoned plant-based eaters.

About Our Experts: Vanessa Rissetto MS, RDN, CDN is a Registered Dietitian Nutritionist with over 10 years of experience as a nutritionist. Stephanie Gomez, MS, RDN, LDN is a Registered Dietitian Nutritionist with over 15 years of experience in health and wellness.

Registered dietitians say the front of the package is marketing — the ingredient list on the back is the actual information.

If there's one myth both experts want to retire immediately, it's the idea that removing animal products from your diet automatically makes it a good one. "'Plant-based' is a marketing term, not a guarantee of health," said Rissetto. "Oreos are technically vegan. I always bring it back to: what is this food actually doing for your body? Ingredients matter more than labels."

The same logic applies to the bigger picture. "It is true that a whole-food, plant-based diet reduces the risk of chronic disease," says Gomez, "however, a vegan diet does not always mean choosing a primarily whole-food, plant-based diet." Rissetto is equally direct: "A whole-food, well-balanced vegan diet? Amazing. A vegan diet built on ultra-processed foods? Not protective. The pattern matters more than the label."

Beans and lentils are a strong foundation, but experts say most people are still coming in under their daily protein target.

Since I went vegetarian as a child and went vegan later on, I must have been asked about my protein intake thousands of times. Protein is the nutrient most vegans are often asked about. Also, according to Rissetto, it's the one they most frequently get wrong. The question, she said, isn't just whether you're eating protein, but whether you're getting enough at each meal to actually support muscle, metabolism, and blood sugar. "Most people are under," she stated.

The assumption that beans, lentils, and oats cover the bases is widespread, but the science is more nuanced. Gomez explained that while plant proteins are genuinely healthful, their fiber content can slow digestion and absorption. That's not a reason to avoid them, but it's a reason to be deliberate about total intake and variety. She noted that "protein needs for healthy adults generally range from 0.8 to 1.6 grams per kilogram of body weight," varying by age, activity level, and individual health conditions.

Diversity matters just as much as quantity. "As humans, we tend to be creatures of habit, and if we transition to a vegan diet without sufficient nutritional knowledge, we may be stuck in a loop that is not geared toward optimal health outcomes," said Gomez. Rather than leaning heavily on a single source, she encourages patients to build in variety — different legumes, whole grains, nuts, seeds, and soy-based foods, each contributing their own nutrient profiles.

Tofu, tempeh and edamame are complete proteins. So are quinoa, hemp seeds, chia, buckwheat and nutritional yeast.

The plant-based world has developed something of a soy obsession, and the experts want to add some perspective. Yes, tofu, tempeh, and edamame are complete proteins, meaning they contain all nine essential amino acids. However, they are far from the only vegan complete proteins available.

"Soy products like tofu, tempeh, and edamame are complete proteins, as are quinoa, hemp seeds, chia seeds, buckwheat, and nutritional yeast," Gomez pointed out. "Also, when we combine hummus and pita, beans and rice, and peanut butter on whole wheat toast, those become complete proteins too." Loading up on soy alone means missing out on the diverse vitamins, minerals, and beneficial compounds that other foods provide. "The healthiest gut microbiome is the most diverse," she added.

Rissetto took a similarly measured view. "Soy is a great protein. It's also not the only one. I'm always thinking about balance and diversity. You don't need to overload on any one food to get it right," she said.

Plant-based patties made with pea, brown rice or faba bean protein are often the better choice for heart health, one dietitian says.

Here's a myth that cuts in a different direction, and it's one that surprises many people. While much of the nutrition conversation around veganism warns against processed foods, Gomez said she frequently sees vegans avoiding plant-based meat products out of unfounded fear. "What I hear among vegans, in many cases, is that they worry about using meat replacements for fear that they are unhealthy," she said.

"The reality is that Beyond Meat and other plant-based products are often much better for heart health and overall well-being than their traditional beef counterparts, which contain more saturated fats, cholesterol, hormones, and antibiotics," she explained. Plant-based meat alternatives also typically contain dietary fiber and other beneficial plant compounds. "Vegans should not fear the inclusion of meat replacements made with pea protein, brown rice protein, faba bean protein, and the like, when they desire a 'meatier' alternative," she said.

"Supplements aren't a failure; they're a tool," says dietitian Vanessa Rissetto — with B12 and D3 topping the list for most vegans.

B12 and vitamin D get all the press for good reasons, but both experts say the list of nutrients worth watching is longer than most vegans realize.

Rissetto flags iron (especially for women), omega-3 fatty acids — specifically DHA and EPA — zinc, iodine, and calcium if dairy hasn't been thoughtfully replaced. "It's not just about avoiding deficiencies," she said. "It's about optimizing function."

Gomez added important context on vitamin D specifically, noting that a large portion of the global population — vegan or not — has insufficient blood levels of the nutrient. Unless you're spending at least 20 minutes in direct sunlight daily during peak UV-B hours, a supplement is likely warranted. She also noted that "vitamin D is fat-soluble and should be consumed with dietary fat" such as avocado or peanut butter to ensure proper absorption.

"Supplements aren't a failure; they're a tool," said Rissetto. Gomez agreed, noting that for most vegans who aren't following a meticulously planned whole-food diet with consistent sun exposure, "taking a vitamin B12 and a vitamin D3 is a good safeguard."

Add roughly five grams of fiber a week rather than overhauling overnight — and drink more water than you think you need.

One of the most common early experiences of going vegan is a dramatically increased fiber intake. That might sound like an unambiguous win, but the body doesn't always respond that way, at least not immediately.

"Your gut gets overwhelmed," said Rissetto. "Bloating, gas, and discomfort can happen. Fiber is great, but your body needs time to adapt. I always tell people: ramp up gradually and hydrate aggressively."

Gomez got even more specific. "If the individual is consuming 5 to 10 grams of fiber at this time, like the average American, then they should aim to add 5 grams of fiber each week as tolerated," she shared. "We must go slow and low when adding fiber, or we will experience uncomfortable conditions."

A single accidental slip doesn't erase every conscious choice that came before it, experts say — give yourself grace and move on.

Perhaps the most psychologically costly myth in some vegan communities is the all-or-nothing belief that accidentally consuming an animal product constitutes a meaningful failure.

"It's not helpful," said Rissetto. "One meal doesn't define your health or your identity. Consistency over time matters. If your approach is so rigid that one mistake derails you, it's not sustainable."

Gomez frames it in deeply human terms. "As imperfect humans living imperfect lives, the best thing we can do is learn to give ourselves grace," she observed. She reminds her patients that many people choose veganism out of compassion — for animals, for the planet — and that a single accidental slip doesn't erase the cumulative weight of all the conscious choices that came before it. "Even if an individual accidentally consumes an animal product, that single instance does not negate all the times the individual consciously chose to avoid causing harm," she said. "One bad day doesn't have to turn into a bad week or a bad month. Forgive yourself and stay on your path."

Both experts recommend an annual physical, a week of food logging, and a check-in with a registered dietitian.

Both experts share a final word of caution for vegans who feel settled and self-sufficient in their approach: confidence isn't the same as accuracy.

"Get objective with your labs, intake, and outcomes," said Rissetto. "Don't rely on how you feel alone. Nutrition isn't just about intention; it's about execution."

Gomez recommended keeping a food diary for at least a week or using a nutrient-tracking app to log everything eaten and consumed. That can help you see whether the diet is actually as complete as it feels. She also encouraged an annual physical and a check-in with a registered dietitian. "Our nutrition behaviors will affect our physical and mental health across a wide range of systems, and we should be mindful about taking the best possible care of ourselves."

The good news, both experts agreed, is that a well-planned vegan diet can be genuinely excellent for long-term health.

Thank you for reading. For more wellness and vegan living, follow me at Yahoo.

Stephanie Gomez, MS, RDN, LDN is a Registered Dietitian Nutritionist completing a doctoral degree in Clinical Nutrition in the fall of 2026. With a master's degree in Dietetics Administration and over 15 years in health and wellness, she has a diverse background in nutrition counseling, fitness instruction, group therapy facilitation, and health education. Through her private practice, Begin Again Nutrition, Stephanie provides instruction and counseling in nutrition, physical and mental fitness, mindfulness, and lifestyle habits to support individuals and groups with mind and body wellness.

Vanessa Rissetto, MS, RD, CDN is a nationally recognized dietitian and the CEO and Co-founder of Culina Health, named one of the TIME100 Most Influential Companies of 2026. She strives to make nutrition care more inclusive and accessible for everyone. Vanessa is one of the most influential voices in the nutrition space and is a frequent on-air expert on The Today Show.

Please note: Robin Raven is a journalist covering health and vegan living. This article is for informational purposes only and does not constitute medical or nutritional advice. Always consult a qualified healthcare provider or registered dietitian before making changes to your diet.