What Are the Problems with a Common Plant-Based Diet?

How do you eat a healthy plant-based diet? What are the nutrients of concern in a vegetarian and vegan diet? Are there certain foods you should avoid while eating right? I get a lot of questions about how to eat vegan and vegetarian. I answer your questions about the best plant-based foods.

A plant-based diet may be a mainstream lifestyle today, but it still comes with a variety of concerns. With more than half of Americans open to eating a plant-based diet, there are many questions about this style of eating. This interest has created a number of plant-based products; the global vegan food market will reach $15.4 billion by 2020. There are plant-based alternatives in almost every section of the supermarket: produce, deli, deli, canned, frozen, bakery, even the meat counter. And plant-based foods, such as dairy and meat, can have very different nutritional content. Additionally, it’s important to keep up with the non-evidence-based information on plant-based diets making the rounds on the Internet. Case in point: The claim that “the dirt in carrots provides enough vitamin B12 to meet your needs” (the answer is “no” it doesn’t!). So how can you choose plant-based foods and ingredients that help meet your nutritional needs for better health?

Research shows that a well-planned plant-based diet, including vegetables and legumes, provides many health benefits, and may even reduce environmental footprint, but there are several important dietary issues to consider. It’s hard to stay up-to-date on nutrition, including research on plant-based foods and their health effects and the best new products on the market. It’s a good idea if you’re new to a plant-based lifestyle to see a registered dietitian who specializes in plant-based diets to assess your nutritional status and create an individualized meal plan that meets your needs. One source of evidence-based information, as well as a list of plant-based diet experts in areas across the country, can be found at the Academy of Nutrition and Dietetics Vegetarian Nutrition Dietetic Practice Group (VNDPG).

I asked top plant-based registered dietitians to explore some of the most common issues they see among their plant-based clients.

Common Eating Disorders and Concerns About Plant-Based Diets

1. Measuring the Plate. People often lack the knowledge of how to create a healthy, nutritious plant-based diet. “For people who are just starting to switch to a plant-based diet, I find that the most common issue I discuss is plate balance and increasing variety. “I have seen many customers who do not understand how to combine food without the plate area being part of the meat,” he said. Parul Kharod, MS, RD, LD, clinical nutritionist and past chair VNDPG.

2. Getting Enough B12. While many vegetarians are aware of the importance of vitamin B12, few understand the complex absorption process and the high amounts required for supplementation, says Alex Caspero, MA, RD of Delish Information. He says, “B12 depends on a protein called intrinsic factor to aid absorption; because of this, small amounts of B12 are able to bind to the internal factor at a time. For those who eat animal products or solid foods frequently, the small amounts of B12 present in these foods are absorbed at a higher percentage. However, when you consume B12 in one large dose, as a supplement, you need much higher doses for absorption. Multivitamins that only contain the RDA of B12 are not enough for vegans. I prefer to go with the European Food Safety Authority’s recommendation of 100 mcg/day from a single B12 supplement. ”

3. Meeting Iodine Requirements. Iodine is a potential concern in plant-based diets, according to Caspero. Although plants contain some iodine, the greatest dietary sources are dairy foods, seafood, and eggs. Seaweed also contains iodine, but the amount varies greatly and depending on which type of seaweed is eaten, the maximum limit of iodine can be reached quickly. Caspero adds, “I like to call iodine the ‘gold’ element because you don’t want too much or too little, you need the right amount. Because of this, I recommend that my vegan clients supplement with 1/2 the RDA of iodine—150 mcg per day—or use iodized salt in cooking.”

4. Avoiding Grains and Grains. There may be misconceptions that you should limit pulses and grains (instead, pile on grains and pulses!). Kharod reports that people may think they can get enough fiber from vegetables alone. “If the food doesn’t contain whole grains or beans because people may not be used to or comfortable with incorporating them into their daily routine, then a low-fiber diet may be a problem,” Kharod said.

5. Eating Too Much. Switching to a plant-based diet can mean fewer calories, Jordan says. “You may need to eat more often to meet their needs, such as three moderate meals and one small meal and/or snack,” he adds.

6. More Fiber. Another issue is GI discomfort associated with the rapid increase in dietary fiber when moving from a Western-style diet to a plant-based diet. “I usually recommend adding plants gradually, and starting with more fruits and vegetables before adding more pulses and grains. I recommend one meatless meal at a time to ease the transition. I also discuss the ‘how’ to eat, such as slowing down, chewing food carefully, sipping water, sitting still after eating, and moving lightly to support digestion,” says Alison Jordan, MMN, RDN, LMNT, CLC, CDCES, founder of thinkgreenwell-being.com.

7. Finding Omega–3s. Although plant foods provide short-chain omega-3 fatty acids in the form of ALA, the conversion to long-chain omega-3 fatty acids may be small. Jordan suggests that her vegan clients supplement with a third-party algae-based EPA supplement and a DHA supplement to support adequate essential fat requirements.

8. Choosing the Right Plant–Fortified Milk. With so many options available at most supermarkets, consumers can have a hard time making the best choice for plant-based milk, says Sherene Chou, MS, RDN, past chair of VNDPG. Chou adds, “I always ask why each person uses milk. As far as milk is concerned, soy milk and pea milk are the best choices based on protein and fat. While other milks have different flavor profiles and can be used in smoothies, cooking, or more. Many plant-based milks are fortified with vitamin D, calcium, B12, and other micronutrients which can be a great and easy way to help fill any gaps.”

For other blogs that cover nutrients in plant-based foods, check out the following:

Meeting Your Nutritional Needs on a Vegan Diet
How to Get Vitamin B12 from a Vegan Diet
How to Find Vegan Calcium Sources

References:

1. Global Vegan Food Market (2017-2027). The EMR. Accessed 9/29/22 here: https://www.expertmarketresearch.com/reports/vegan-food-market.
2. Climate Change and America’s Food. Earth Day Network. Accessed 9/29/22 here: