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Evidence Based

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What is a Plant-Based Diet and Is It Right For You?

Written by Dr. Ruscio on August 14, 2023

Written by Dr. Ruscio on August 14, 2023 — Reviewed by Aimee Gallo

Going Completely Plant-Based With Your Diet Isn’t Always Best

• What is a Plant-Based Diet?|
• Plant-Based Diet Research|
• Nutrients: Plant-Based vs Omnivorous|
• Is Plant-Based Right For You?|
• The Risks of Strictly Plant-Based|
• Plant-Based Diets Can Improve Health|

Plant-based diets have gained popularity over the past several years. It’s estimated that the number of Americans following a vegan diet increased by 600% between 2014 and 2018 [1], and you’ve probably seen “plant-based” labels proudly displayed on a variety of products in the grocery store and on restaurant menus. So, what is a plant-based diet, anyway?

A plant-based diet generally refers to a meal pattern that contains more vegetables, fruits, grains, beans, and nuts, and less meat, fish, and poultry. While we sometimes think of them as vegetarian or vegan, plant-based diets can, and often do, include animal products, albeit to a lesser extent. Research suggests that this type of eating style is associated with health benefits, but I don’t want you to get caught up in thinking that plants are the only foods you should be eating. The truth is, a balanced, healthy diet that includes some combination of both plant and animal foods is probably optimal for most people.

While I have no overt opposition to a plant-based diet, and I certainly agree that adding more plant diversity overall is beneficial, I am concerned with the vilification of specific foods (like red meat) or the thought that one type of diet is right for everyone. It’s also important to understand that just having the “plant-based” label, doesn’t necessarily mean a food is health-promoting. Many plant-based foods are processed, contain an unhealthy amount of sugar, and/or are difficult to digest.

In this article, I’ll answer the question, “what is a plant-based diet?” I’ll also dive into what the research says about its benefits and limitations, as well as why some people actually do better when eating fewer plant foods. Let me start off by defining a plant-based diet and giving you some examples of plant-based dietary patterns.

What is a Plant-Based Diet?

Following a plant-based diet may certainly mean avoiding all animal products, as is the case with the vegan diet. But more often than not, it means plant foods like beans (chickpeas, black beans), legumes (cashews, tempeh, lentils), nuts, seeds (quinoa), grains (brown rice, whole wheat bread), fruits, and veggies (leafy greens) take center-stage, and animal foods like meat, poultry, fish, and dairy products hang out in the background. 

Plant-based diets exist on a spectrum, so here’s a chart of some popular plant-based eating patterns along with what’s included and restricted for each: 

As you can see, outside of the vegan diet, all of these include animal products to a certain extent. Most of these diets also recommend reducing the intake of sugar and processed foods, but there are definitely ultra-processed plant protein sources and other unhealthy plant-based foods out there on the market. So, simply eating food with a “plant-based” label doesn’t mean it’s a health-promoting option.

In the clinic, I’ve found that a balance of both plant and animal foods is helpful for most people. And honestly, you can make any diet “plant-based” by incorporating more fruits, vegetables, beans, nuts, and seeds. 

I tend to prefer the Paleo diet, as it is a whole foods diet that emphasizes plant and animal-based foods and limits processed foods without being overly strict. But the key is to find the dietary pattern that works best for you personally and to always listen to your body. There’s no need to force yourself to follow a diet that doesn’t feel right simply because it’s the latest trend or the media has promoted it as “environment-friendly.” 

However, there’s no denying that plant foods provide great benefits, so let’s review what the research says about the health effects of plants and plant-based diets.

Plant-Based Diet Research Findings

Let me preface this by saying much of our nutrition research on plant-based diets (and other types of diets) is observational in nature, which means it can’t tell us definitively about cause and effect. A lot of the observational research on plant-based diets is positive, so it’s tempting to say that these diets definitely lead to better health outcomes over diets that contain meat, but we just can’t say that with the information we currently have. Let me explain.

It could be that some of the positive findings surrounding plant-based diets are related to confounding factors – for example, people who tend to eat a plant-based diet also generally lead healthier lives by exercising, avoiding smoking, and managing their stress levels. Or, benefits may be seen from eliminating processed foods and sugar, and not necessarily the specific plant-based diet itself.

These factors may actually be equally as responsible for the positive benefits found in plant-based diet research trials. I’m not saying plant-based diets don’t have great health benefits, but it’s important to view the research in the right context. Alright, with that in mind, let’s dive in.

Health Effects of Plant-Based Diets

Epidemiological research has found plant-based diets to be good for health. Meta-analyses have shown that when compared to standard diets that contain meat, the benefits of a plant-based diet include better weight loss, blood pressure, and cholesterol [2, 3, 4]. And people who follow plant-based diets may have a lower risk of certain types of cardiovascular disease [5] and type 2 diabetes [5, 6, 7]:

• In one meta-analysis, people who closely followed a plant-based diet that included healthy plant-based foods like fruits, vegetables, whole grains, legumes, and nuts had a 30% lower risk of developing type 2 diabetes compared to those who didn’t [7].
• For those already diagnosed with type 2 diabetes, switching from eating meat to a plant-based diet for four months led to significant reductions in body weight (especially belly fat), body mass index (BMI), and waist circumference, even without calorie restriction [2].

While these results seem promising, I want to stress the importance of following a well-balanced plant-based diet. Simply giving up meat and continuing to eat ultra-processed plant-based foods is probably not going to give you the best results. 

When looking at vegetarian and vegan diets specifically, a large observational study found that compared to meat eaters, vegetarians and vegans had a lower risk of diabetes, diverticular disease, and cataracts. Additionally, vegetarians may be better protected from heart disease, kidney stones, and possibly some cancers [8]. 

On the other hand, this study showed that vegetarians were more likely to develop stroke, and both vegetarians and vegans had a higher risk of bone fractures [8]. This association may be due to the lack of certain nutrients from meat and fish, like vitamin B12, vitamin D, calcium, and omega-3 fatty acids, or from an overly-restrictive diet and insufficient protein intake.

Another meta-analysis found evidence that following a vegetarian — but not vegan — diet was associated with a lower risk of cardiovascular disease, though neither plant-based diet had a lower risk of stroke compared to a diet that incorporated both plant and animal foods [5]. 

Other high-quality research showed that compared to an omnivorous diet, vegetarian diets were associated with a lower risk of ischemic heart disease, but did not differ much in reducing the risk of overall heart or cerebrovascular disease, specific cancers, or dying from cancer. Neither a vegan nor vegetarian diet was found to reduce the risk of all-cause mortality (death due to any cause) [6]. 

Most of these observational studies have been performed on adults, so what about kids who follow plant-based diets? An observational study of children who were vegetarian, vegan, or omnivorous (eating both plant and animal foods) found that compared to omnivores [9]:

• Vegan kids had a healthier cardiovascular risk profile but they were also shorter, had lower bone mineral content, and a greater risk of nutritional deficiencies. 
• Vegetarian kids had less issues with nutritional deficiency but a worse cardiovascular risk profile than the omnivores.

This doesn’t necessarily mean your kids have to choose heart health over being tall or having strong bones, it just means the plant-based diet needs to be well-planned and contain all the nutrients growing kids require. Being overly strict during times of increased nutritional needs like childhood, pregnancy, or lactation is best avoided.

As you can see, the majority of the research is mixed, and remember, the nature of this type of research doesn’t tell us cause and effect. If you’ve heard that plant-based diets like vegetarian and vegan are superior for your health, I want to reassure you that you don’t need to force yourself to follow either of these diets to experience optimal health outcomes. 

This research reminds us that there’s no one perfect diet — especially one that can fit every person’s individual needs. Trying to adhere to a specific plant-based diet for its proposed health benefits can cause more stress than it is helpful, and finding a balanced diet that incorporates plant-based foods and makes you feel best is preferred over any specific diet.

You may be curious how a plant-based diet stacks up against an omnivorous one when it comes to nutrient and calorie content, so let’s take a look.

Nutrient Content: Plant-Based versus Omnivorous Diets

It’s important to obtain adequate amounts of nutrients for optimal health, and we get those nutrients from the food we eat. While a lot of different nutrients exist in plant-based foods, if you’re only eating plants, you could be missing out on valuable nutrients that are found in animal-based foods.

A 2022 systematic review of 141 studies from around the world compared the nutrient intake and status of adults eating plant-based diets versus those that included meat. Here’s an overview of their findings [10]:

• Plant-based eaters consumed more fiber, polyunsaturated fatty acids (PUFA), folate, vitamins C and E, and magnesium but less protein, and eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
• Plant-based eaters had lower intake and blood levels of vitamin B12, vitamin D, iron, zinc, iodine, calcium, and bone turnover markers.
• Vegans consumed the least B12, calcium, and iodine, and had lower blood iodine levels and bone mineral density. 
• Meat eaters were more likely to consume less fiber, PUFA, alpha-linolenic acid (ALA), folate, vitamins D and E, calcium, and magnesium.

In addition, here’s a summary chart comparing total calorie and macronutrient intake between meat eaters, vegans, and vegetarians. Red text indicates the levels are below minimum standard recommendations, and green text indicates levels are within or above standard recommendations [10]:

As you can see, both plant and animal-based diets can fall short of important nutrients if you’re not careful. For example, strict vegans and vegetarians may not be getting enough valuable healthy fats (omega-3’s), and meat eaters may be under-consuming fiber. Additionally, most people already fall short when it comes to optimal protein intake, and those on a strict plant-based diet will likely need to pay even closer attention to how much they are consuming. 

If you’d like to take advantage of the health benefits associated with plant-based diets there are many options that aren’t as restrictive as fully vegetarian or vegan diets. If you’re committed to following a vegetarian or vegan diet, it’s definitely important to consider targeted supplementation to avoid nutritional deficiencies. That being said, a few of my patients in the clinic do respond best to a fully vegetarian diet, while others find a meat-focused diet (only animal-based foods) is easier on their digestive tract, at least initially. 

It’s important to understand that these types of diets aren’t typically used long-term. At the end of the day, balance is key for most people. While restrictive diets (plant or animal-based) can be helpful for some people at first, most people are able to add back most foods without difficulty as the gut heals. The end goal is to be able to have a full spectrum of plant and animal foods in your diet to not only avoid the risk of nutrient deficiencies but enjoy your food to the fullest.

So let’s look more closely at these types of situations, and a step-by-step process you can use to determine what’s right for you. 

Is Plant-Based Right For You?

When it comes to diet, I recommend dietary patterns (like Paleo or Mediterranean) for most people, as opposed to singling out or stressing over specific foods. These meal plans are similar to fully plant-based diets in the sense that they eliminate processed foods and sugars while emphasizing whole foods. 

I find this provides more food freedom and helps avoid making you neurotic about every food you’re putting into your body. However, I’ve found some people do respond best to a fully vegetarian diet, and some observational research suggests a temporary vegetarian diet may be beneficial for people with:

• Type 2 diabetes: A plant-based diet for 4 months has been found to promote greater loss of belly fat [2].
• High blood pressure: Plant-based diets that include some animal products may significantly reduce blood pressure [3].
• High cholesterol: Vegetarian diets have been associated with lower average total, LDL, and HDL cholesterol [4].

So, if you’ve been diagnosed with any of these, and you’re following the standard American diet, which has been shown to promote chronic disease development, it may be worth it to trial a diet that includes more plants than animal foods. While adding more plants is usually a good thing, there can be some risks to following a strictly plant-based diet, so let’s review what you may want to consider.  

The Risks of Being Strictly Plant-Based

If you’re not consuming a lot of plants in your diet right now, it’s probably a good idea to increase the amount and variety. However, research suggests plant-based diets may be difficult to digest and they can exacerbate negative symptoms for certain people with gut-related conditions like:

• IBS or SIBO [11, 12, 13, 14]
• FODMAP or fiber sensitivity [15]
• Digestive symptoms like gas, bloating, abdominal pain, heartburn, nausea, constipation [13, 14, 16, 17]
• Active inflammatory bowel disease (IBD) or other bowel diseases like bowel obstruction, diverticulitis, and gut infections [17]
• Abdominal surgery [17]
• Malabsorption [18, 19]

I’m all for increasing the number of plant foods you consume. However, if you start on this process and notice an uptick in digestive symptoms, or if you have a sensitive gut, irritable bowel syndrome (IBS), or small intestinal bacterial overgrowth (SIBO), a temporary diet that reduces plant foods may be helpful and here’s why:

Plant foods contain many nutrients, among them fiber. You may have read that you need to push fiber intake as high as possible, but eating certain fibers can be difficult for an inflamed gut. As I discuss in Healthy Gut, Healthy You, low carbohydrate and low-prebiotic fiber diets have impressive evidence for improving IBS [20, 21, 22]. The low FODMAP diet can provide significant relief while you’re working on gut healing [14, 16, 23, 24, 25].

Additionally, strictly plant-based diets may be lacking in certain nutrients like iron, protein, vitamin B6, and essential fatty acids (EPA and DHA). Some people have higher demand for these nutrients and plant-based diets may not provide adequate amounts. If you fit into any of the following categories, it’s important to talk to your healthcare provider or a nutritionist. If you can’t increase food sources of these nutrients, you may need to consider supplementation. Populations at higher risk of nutrient deficiencies include [19]:

• Menstruating women
• Athletes
• Pregnant and lactating women
• Children
• Teens
• Infants
• Older adults

And as a final recap, plant-based diets may not provide adequate amounts of(19):

• Vitamin B12, especially for vegans
• Calcium
• Vitamin D
• Zinc
• Iodine

This isn’t to say that most plant-based diets can’t provide all the nutrients you need, they just need to be well-planned with nutrient-dense foods, and possibly dietary supplements in certain cases. If you’re curious as to how your current diet stacks up, there are many nutrition apps, like Cronometer and myfitnesspal that will estimate your nutrient intake and you can adjust your diet from there.

So, how do you decide what diet is best? How much plant-based is too plant-based? I want to keep this as simple as possible, so let me share a step-by-step process similar to what I use in the clinic.

Find the Right Balance of Plant-Based Foods: A Step-By-Step Guide

If you’d like to add more plant foods to your diet but just don’t know where to start, here’s an easy step-by-step process you may want to navigate through:

• Step One:  Improve your food quality by reducing sugar and processed foods, and bring in more plant-based foods like fruits, vegetables, beans, nuts, seeds, legumes, fermented foods, and whole grains. If you feel great, then move on to step 4. But if you notice an increase in digestive symptoms with this change, move on to step 2. 
• Step Two: Try a basic elimination diet that limits plant foods, like low FODMAP, for several weeks. You could also consider adding intermittent fasting or an Elemental Heal shake to replace one or two meals per day temporarily until things settle down. 
• Step Three: If your symptoms have improved significantly, then try reintroducing the eliminated plant-based foods and slowly increase your overall plant diversity to tolerance.
• Step Four: Experiment with a maintenance dietary pattern like Paleo or Mediterranean, depending on your lifestyle and preference. 

Sometimes less is more when it comes to fiber, and since plant foods are the foods that contain fiber, a temporary reduction can help to improve your symptoms. As your gut heals, you can always work toward adding more plants and plant diversity back to your maintenance dietary pattern. 

Plant-Based Diets Can Improve Health

What is a plant-based diet? In general, it’s a dietary pattern that focuses on fruits, vegetables, beans, legumes, nuts, seeds, and whole grains with lesser amounts of meat, eggs, dairy, and fish. Although a plant-based diet could also be completely devoid of animal foods. 

Increasing plant foods is a great idea, and observational studies have suggested that plant-based diets may help to promote wellness, reduce cardiovascular disease risk, and combat obesity, high blood sugar, and other chronic diseases. 

But you don’t need to sacrifice animal products or go to extremes in order to experience vibrant health. The key is to find the right eating pattern for you personally, and I’ve found a balance of both plant and animal-based foods tends to work for most patients in my clinic. However, there are some people who feel better when they limit plant-based foods, at least temporarily, while working to improve gut health. 

If you want to move to a plant-based diet, it’s best to start slow by adding in more plant foods and reducing sugar and processed foods. After all, a highly processed, plant-based diet isn’t better than a well-planned, whole-food omnivorous diet just because it’s “plant-based.” 

If you would like a complete step-by-step gut healing guide, check out my book, Healthy Gut, Healthy You. If you need more personalized guidance, contact us at the Ruscio Institute for Functional Health.

The Ruscio Institute has developed a range of high-quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.