Types of Vegetarian Diets | U.S. News

There are undoubtedly many eating approaches and diet trends, but the one diet that continues to be popular among Americans is the vegetarian diet.

According to an August 2023 Gallup poll on consumption habits, 4% of Americans identify as being vegetarian. While that number has remained relatively stable over the years, the trend toward more plant-based eating is on the rise. A 2020 survey also conducted by Gallup showed that nearly 1 in 4 people in the U.S. reported eating less meat than the year before, with 70% of respondents citing health concerns as a major reason for reducing their meat consumption.

In addition to personal health, concerns about the environment, food safety and animal welfare topped respondents’ list of major reasons for either refraining from eating or completely eliminating meat in their diets.

While there is no singular vegetarian diet, there are various forms of vegetarianism – each with its own set of advantages, disadvantages and restrictions.

Research by the Food and Agriculture Organization of the United Nations shows that animal agriculture accounts for an estimated 14.5% of global greenhouse gas emissions. In fact, if global producers and consumers gradually replaced a carnivorous diet with a plant-only diet over the next 15 years, it would reduce enough greenhouse gas emissions to offset emissions from other sectors – including transportation and energy – for the following 30 to 50 years, according to 2022 research published in PLOS Climate.

However, one of the main reasons people choose a vegetarian diet is for health reasons. Plant-based diets have been linked to a lower risk of chronic diseases, including heart disease, hypertension and Type 2 diabetes.

“Whatever your reason – or reasons – may be to eat vegetarian, there’s no wrong answer when considering meatless meals,” says Lisa Jones, a registered dietitian based in Philadelphia.

Plant-based diets are associated with:

In a 2018 study published in the journal Progress in Cardiovascular Diseases, researchers found that vegetarian dietary patterns reduced cardiovascular disease mortality and coronary heart disease risk by 40%. Their findings further confirm the benefits of a vegetarian diet on lower blood pressure, lower blood lipids and diabetes management.

Research also shows that a vegetarian diet could be beneficial to our health in other ways. In a 2019 study published in the journal Nutrients, researchers followed 4,839 participants over an average of six years to evaluate the association between a vegetarian diet and gallstone disease. Their findings showed that a vegetarian diet was associated with a decreased risk of gallstone disease in women by lowering cholesterol, which – at high levels – has been identified as a risk factor for the disease.

Depending on what foods you exclude from your diet, a vegetarian eating regimen may be lacking in these nutrients that are naturally present and more abundant in animal food products than other food sources:

“If well-planned, these nutrients can be obtained, whether naturally and/or with supplemented products,” says Kaylee Jacks, a registered dietitian with Texas Health Sports Medicine in Dallas.

While many vitamin and mineral supplements are commercially available in pill form, experts agree that the best way to get these nutrients is by consuming whole foods. For example, instead of taking calcium supplements, making sure you consume enough high-calcium foods – such as calcium-fortified plant-based milk, yogurt and cooked kale – will help you meet your recommended dietary intake.

“Seeking out a health care professional to discuss supplementation is beneficial for any vegetarian diet,” says Betsy Fears, a registered dietitian nutritionist at The Polyclinic in Seattle, Washington.

There are several versions of the vegetarian diet:

“Flexitarians prioritize plant-based foods but can include small amounts of all animal products when they choose,” Fears says. “The ability to occasionally consume animal products can make plant-based eating more sustainable for many people.”

With the flexitarian diet, you reap all the health benefits of a vegetarian diet without making too many dietary changes. It’s no wonder, then, that the flexitarian diet ranked No. 2 in U.S. News’ Best Diets Overall.

Advantages of a flexitarian diet include:

There are no known health risks of disadvantages associated with the flexitarian diet.

The beauty of the flexitarian diet is that it doesn’t eliminate any foods or food groups. It simply encourages people to moderate intake of meat, dairy and egg products.

Stemming from the Latin word “lacto” for milk and “ovo” for egg, this vegetarian diet allows the consumption of dairy and egg products, while eliminating meat, poultry and fish. For most people, this is a healthy diet.

Advantages of the lacto-ovo vegetarian diet include:

Disadvantages of the lacto-ovo vegetarian diet:

You’ll need to watch your intake of saturated fat from cheese and milk. These foods can high in saturated fat, which research suggests can contribute to heart disease when consumed in high quantities.

This vegetarian diet eliminates meat, poultry, fish and eggs but does allow dairy products.

“It’s important to get the low-fat or fat-free versions of these dairy products because full-fat dairy is high in saturated fat,” Jacks says.

Advantages of the lacto-vegetarian diet include:

Disadvantages of the lacto-vegetarian diet include:

If you love scrambled eggs but could go without dairy, an ovo-vegetarian diet may be right for you. This version of a vegetarian diet eliminates meat, poultry, fish and dairy, but it does include eggs and any foods containing egg.

“This diet has all the benefits of a vegan diet and the benefits from including eggs,” Jacks says.

Advantages of the ovo-vegetarian diet:

Disadvantages of the ovo-vegetarian diet:

For most healthy adults, one to two eggs a day should be healthy and safe, as long as eggs are part of a well-balanced and varied diet.

In previous years, experts and dietary guidelines recommended consuming no more than 300 milligrams of dietary cholesterol daily for cardiovascular health. However, due to a lack of evidence between dietary cholesterol and cardiovascular risk, nutritional guidance was inconsistent.

A pescatarian diet is a plant-based eating regimen similar to the lacto-ovo vegetarian diet, but the main difference is that it includes seafood as a main protein source.

“Consuming seafood can make getting omega-3 fatty acids and protein easier than other vegetarian diets,” Fears says.

Omega-3s are polyunsaturated fats, which research suggests help reduce harmful inflammation and keep cholesterol and blood pressure levels in the healthy range. This can help reduce the risk of heart disease.

Advantages of a pescatarian diet:

Disadvantages of a pescatarian diet:

Fish with high mercury levels include cod, mackerel, marlin and swordfish. Instead, the U.S. Food and Drug Administration and the U.S. Environmental Protection Agency recommend pregnant and breastfeeding women consume no more than one to two servings, or about 4 ounces, and children, depending on age, between 1 and 4 ounces of low-mercury fish.

The vegan diet is the most restrictive version of a vegetarian diet, as it eliminates all animal-derived foods, including meat, fish, eggs and dairy products. It also excludes foods produced by insects, such as honey, and supplements that use capsule shells made of gelatin from animal parts, usually from cows or pigs.

“A vegan diet consists of foods strictly from plants, such as fruits, vegetables, nuts and grains,” Jacks says.

These foods are typically low in calories and high in fiber, vitamins and minerals.

Advantages of a vegan diet:

Disadvantages of a vegan diet:

There are several versions of the vegetarian diet – each with their own set of restrictions. When deciding on which type of diet to follow, it’s important to take into consideration your lifestyle, values, reasons for switching to a vegetarian diet and sustainability over the long term.

Remember: There’s no right or wrong answer when it comes to choosing a plant-based eating approach. You should feel free to experiment with the different types of vegetarian diets until you find one that works best for you.