What is a Plant-Based Diet? A Science-Backed Guide to Eating Less Meat

Increasing awareness of the association between diet and disease has sparked global interest in the health benefits of eating more plants. Whether you’re a strict raw vegan or prefer dabbling in Meatless Monday, plant-based alternatives are on the rise at grocery stores, restaurants and fast-food chains across the United States, making meat-free eating easier than ever.

Yet, as with all food trends, skepticism remains. Aren’t humans supposed to eat meat? What is a plant-based diet, anyway? 

Here’s everything you need to know if you’re hungry for answers about what it means to eat less animal products, where to start and why you might want to consider it.

What is a plant-based diet?

With so many different approaches to eating less meat and more plants, there remains considerable confusion about what it means to be plant-based. At a basic level, a plant-based diet emphasizes whole, fresh foods over meat and dairy. 

A plant-based diet consists of:

• Fruits, vegetables and leafy greens
• Beans, lentils and other legumes
• Whole grains like rice, quinoa and farro
• Healthy fats, like avocados and nuts
• Nut-based milks and cheeses

Beyond the basics, there are variations within the plant-based spectrum, including vegan, vegetarian and whole food plant-based (WFPB). 

What is a whole food plant-based diet?

A whole food plant-based diet (WFPB) is what many doctors and nutritionists recommend to people who want to eat healthier, lose weight and reduce their risk of common diseases.

People who follow a WFPB diet eat mostly plants, yet they don’t fully restrict themselves from eating animal products. Rather, they’re more selective about the animal products they do choose and limit the amounts that make it onto their plate. 

WFPB eaters typically avoid red meat and conventionally processed animal products. These health-conscious eaters opt for lean meats like chicken and fish, though they eat them sparingly. Eating a diet high in whole foods offers the benefits of eating more plants while providing flexibility. 

This diet is a popular choice for people who are interested in the health benefits of going vegan, but aren’t ready (or willing) to make the full commitment.

What is a vegetarian diet?

People who eat vegetarian abstain from all meat products, including fish. Still, vegetarianism can be divided into four main subgroups:

• Lacto-ovo-vegetarians still eat eggs and dairy products, including milk, cheese and yogurt
• Lacto-vegetarians eat cheese and milk products, but no eggs
• Ovo-vegetarians don’t eat dairy products, but eat eggs
• Pescatarians follow the same diet as lacto-ovo vegetarians, but also eat fish

An important consideration for those following a plant-based diet is where their food is sourced. Vegetarians tend to be conscious of where the animal products they consume come from, including how animals are raised and treated. For example, they’re more likely to buy eggs from pasture-raised hens, or salmon from sustainable fishermen.

What is a vegan diet?

A vegan diet is the most strict of all plant-based diets. Vegans abstain from eating all animal products and foods from animal-derived sources. Someone who follows a vegan diet will use plant-based alternatives to common foods, such as:

• Almond, oat, cashew, rice or flax milk
• Cashew or soy cheese
• Soy and coconut yogurt
• Tempeh and tofu
• Seitan and veggie burgers
• Flax or chia egg

As with vegetarianism, there are variations of the vegan diet. Some follow a raw vegan diet, where they don’t eat anything that has been cooked or otherwise processed. Vegan diets can also intersect with other popular diets, like keto, paleo or gluten-free. 

Health benefits of a plant-based diet

People opt to eat more plants for myriad personal and societal reasons, including animal welfare, sustainability and ethics. Regardless of which issue drives your decision, scientists and plant-based eaters agree: reducing your consumption of animals is good for your health(1).

So what is a plant-based diet and what are the health benefits? The most prominent benefit of following a plant-based diet is that it greatly reduces the health risks posed by the Standard American Diet (SAD). The traditional North American diet, typically referred to as SAD, is largely responsible for the high rates of obesity and disease in the West. 

Fortunately, consuming more plant-based foods can lower or even eliminate the health risks posed by the standard American diet. 

1. Reduce obesity and diabetes

People who regularly consume conventional foods like white bread, frozen dinners and soft drinks are taking in excessive amounts of sugar (2). A diet high in sugar can lead to a range of health problems, including high blood pressure, high cholesterol, diabetes and liver disease — even in people who maintain an otherwise healthy weight (3,4). 

A diet high in plant foods is much lower in sugar and saturated fats, and has been shown to promote weight loss and reduce diabetes-related insulin resistance (5).

2. Lower risk of cancer

The SAD also includes processed meat and dairy products, both proven to significantly increase the risk of certain diseases. When consumed daily, a single serving of processed meat can increase a person's risk of cancer by 18% (6). Moreover, the carcinogenic nature of hot dogs, beef jerky and other processed meats is correlated with an increased risk of colorectal, breast, pancreatic and prostate cancers (7).

In contrast, a plant-based diet is high in fruit and vegetable-derived phytochemicals (plant compounds that offer protective benefits) and vitamin C, which can boost immunity while preventing some forms of cancer (8). Additional research shows that a low-fat, plant-based diet, in combination with stress management and exercise, can delay or eliminate treatment in individuals with early-stage prostate cancer (9).

3. Reduce cardiovascular disease 

The standard American diet is high in processed and red meats, which have been shown to elevate the risk of cardiovascular disease (10). Withcardiovascular disease serving as the leading cause of death in the United States, this is no small risk (11).

In comparison, cultures that eat primarily plants and little-to-no meat (e.g., rural China, central Africa) have extremely low rates of heart disease (12). 

Science also shows that a diet rich in plants is better for your heart. In particular, individuals who consume more plants and less red meat experience lower blood pressure, body mass index and cholesterol. Since these are all risk factors for developing heart disease, these findings strongly support the idea that a plant-based diet can significantly improve cardiovascular health (13).

4. Reduce aging and AGEs

Diets high in animal protein also elevate blood compounds called advanced glycation end products (AGEs). The buildup of AGEs in a person’s bloodstream increasesoxidative stress and inflammation, which in turn increases their risk of kidney failure, high blood pressure, liver disease, diabetes and Alzheimer’s. 

Though AGEs occur naturally as a result of aging, food is the most common external source. AGEs manifest in foods that have been cooked at a high temperature, including processed foods and meat dishes like grilled chicken and broiled steak (14). 

Alternatively, a diet consisting of low-fat plant foods contains far fewer AGEs and, when combined with taurine, has been recommended to mitigate symptoms of diabetes and kidney disease (15).

How to start eating more plants

The internet is filled with blogs, articles and resources on how to eat more plant-based foods. Blogs are a great place to find information and recipes about adopting a more plant-focused lifestyle. 

Leading vegan and vegetarian food blogs include:

Cookie and Kate

Elsa’s Wholesome Life

Oh She Glows

Vegan Yack Attack

Healthy Happy Life

Center for Nutrition Studies

The Colorful Kitchen

Pick up Limes

Staples of a Whole Food Plant-Based Diet

It’s helpful to categorize plant-based foods into groups you can use to fill your plate. When you’re stuck on what to make for dinner, consider these categories to piece something together. 

1. Fresh fruits and vegetables. These are the foundation of any whole-food diet. Packed with vitamins, minerals and gut-friendly fiber, fruits and vegetables should be a mainstay in your fridge. Some trusty staples to keep on hand include apples, citrus fruits, bananas, broccoli, cabbage, peppers, greens and so on. 
2. Tubers. More commonly known as root vegetables, tubers encompass potatoes, turnips, beets, sweet potatoes, carrots and radishes.
3. Whole grains. In a plant-based diet, whole grains are your go-to for hearty nutrition. With their complex carbohydrates, they’ll fill you up and provide you with sustained energy. Whole grains to keep on hand include brown rice, millet, quinoa, farro, oats, barley, and other grains in their whole forms. 
4. Legumes. Beans, lentils andpulses are packed with protein and fiber. Buy them dried in bulk or keep cans on hand when you need something quick. 
5. Healthy fats. Good sources of fat include avocados, walnuts, olive oil, nut butters, and seeds. These will help keep you full, stabilize blood sugar and sustain your energy throughout the day.

Plant-Based Meat Alternatives

With vegan food alternatives on the rise, it’s easy to rely on processed, plant-based versions of your favorite foods (16). But even if they’re plant-based, it’s important to limit your consumption of packaged and processed fast foods because they may be high in sodium, sugar and harmful preservatives. 

Instead, opt for whole foods in place of meat or dairy to make common recipes more nutritious without relying on processed options.

Consider these options for wholesome, healthy meat alternatives:

• Grill a portobello mushroom cap rather than a burger
• Try lentils or walnuts instead of ground beef in vegan lasagna or tacos
• Opt for garbanzo beans in place of chicken salad on a sandwich
• Eat jackfruit in a salad or sandwich instead of pulled pork
• Bake and season a halved cauliflower in place of a steak dinner

These simple swaps can sizably reduce your meat intake and have a long-term impact on your overall health. 

Finding alternatives to dairy

To maximize the benefits of a plant-based diet, consider these dairy-free alternatives, many of which you can make at home:

• Almond, coconut, soy, rice, oat, flax or hemp milk
• Cashew cheese or sour cream
• Coconut or cashew yogurt
• Nacho cheese made from carrots and potatoes
• Nutritional yeast in place of parmesan cheese

The easiest way to eat more plants is to replace foods you already love with vegetarian or vegan options. When you eat the foods you love and enjoy the same delicious flavors through seasonings and sauces, it will be easier to stick with a plant-based regimen.

Stay full and get enough protein on a plant-based diet

Protein and satiety are common concerns when switching to a plant-based diet. Since plant-based foods are lower in fat and calories, it’s normal to think that you might not eat enough to keep you full.

Fortunately, the plant world is filled with foods that provide plenty of protein to keep you full and energized. 

The best plant protein sources include:

• Legumes and lentils, which have fiber, vitamins, minerals and protein (9 g per ½ cup)
• Hemp seeds, which provide all nine essential amino acids and protein (10 g per 3 tbs)
• Nuts offer protein (5 to 6 g per ¼ cup) andhealthy unsaturated fats
• Quinoa has filling protein (8 g per cup) and all nine essential amino acids
• Nutritional yeast has essential nutrients and protein (8 g per ¼ cup)
• Tofu is a versatile powerhouse, made with protein-rich soybeans and commonly fortified with calcium (12 g per 4 oz)
• Tempeh, made from fermented soybeans, packs a punch of protein and gut-healthy probiotics (21 g per 4 oz)

Protein and calorie needs vary by activity level, gender and general lifestyle, but understanding your daily requirements can ensure you stay full on a plant-based diet.

Don’t forget your B12

A balanced plant-based diet, full of the staple foods mentioned above, will provide you with almost all of the nutrients you need. The only exception isvitamin B12, a nutrient important for blood health and energy. 

Those who eat meat get vitamin B12 from animal tissue, where it’s stored as a byproduct of the anaerobic bacteria living in the intestines of ruminant animals (e.g., cows and sheep). Livestock are often supplemented with B12 as well, and pick up the nutrient from grazing on manure-tainted feeding lots. 

Given modern hygiene practices, the fruits and vegetables we eat today are washed clean of any soil remnants before they’re eaten. As a result, humans eating plant-based foods won’t receive this vitamin naturally. To ensure you’re getting enough of this vitamin in your diet, eat foods or milk alternativesfortified with B12 or take a supplement. 

With a recommended daily amount for adults at 2.4mcg per day, you’re likely to get more than enough from any B12 or multivitamin on the market today. If you’re concerned about your levels, check in with your doctor for a simple blood test at your annual physical exam. 

In summary

Countless studies show that the Standard American Diet contributes to a host of health problems, including cardiovascular disease, diabetes, obesity and certain cancers. The good news is that vegan and vegetarian lifestyles can prevent and even reverse the effects of eating a diet high in meat and dairy. Armed with new scientific evidence around the health benefits of plant-based eating, consumers can make more informed decisions when making the switch.

Michelle Polizzi, Contributing Writer, Physician’s Choice