Types of Plant-based Diets

Vegetarian diets usually include all fruits, vegetables, grains, legumes, nuts and seeds, and may include eggs and dairy products. All of these diets typically exclude all meats (flesh). Plant-based is an encompassing term for vegan and vegetarian diets that are defined by the type or frequency of animal product(s) consumed. There also are subsets within these diets, which are defined by the types of animal-based products that are consumed or avoided:

• Lacto-ovo-vegetarian: Consumes eggs and dairy products
• Lacto-vegetarian: Consumes dairy products
• Ovo-vegetarian: Consumes eggs
• Pescetarian: Consumes fish
• Semi-vegetarian: Occasionally consumes meat (once or twice per week) or excludes all red meat
• Flexitarian: Rarely consumes meat (once or twice per month)
• Vegan: Does not consume any animal products

Given this range of plant-based classifications, it can be difficult to determine from the available research exactly which types provide the most health benefits. Cardiovascular disease (CVD), for example, takes years to develop, so a well-controlled, short-term study cannot adequately assess CVD risk. Therefore, we must rely on examining the correlations between dietary habits and health factors. Overall, a well-planned and executed vegetarian diet can provide adequate nutrition, promote overall health and lower the risk of major chronic diseases.

Let’s take a look at some of the specific health benefits of following a plant-based diet.

Benefit #1: Increased Healthy Food Intake

Eating a variety of vegetables and whole fruits is a key recommendation of healthy eating patterns. A varied consumption of fruits, vegetables, whole-grains, legumes and nuts at an appropriate calorie level usually leads to an adequate intake of dietary fiber and a low intake of saturated fat and hydrogenated vegetable oils. As a result, vegetarians commonly have lower body mass indexes (BMI), LDL-cholesterol, blood pressure and reduced rates of stroke, type 2 diabetes, certain cancers, and death from heart diseasethan do non-vegetarians.

Further, vegetarian eating patterns are rich in health-promoting phytochemicals and vitamins C and E, which function as antioxidants to protect against oxidative stress. Additionally, these eating patterns provide magnesium and potassium rich foods which can improve insulin sensitivity and vascular function, respectively The dietary fiber along with phytochemicals can help improve and maintain gut the microbiome.

To summarize, potential mechanisms for improved health from vegetarian eating plans include weight loss/maintenance, blood sugar control, improved lipid profile, reduced blood pressure, decreased inflammation and improved gut health.

Benefit #2: Decreased Unhealthy Food Intake

Several dietary factors in animal foods have been associated with increased risk of CVD. Historically, saturated fats, prevalent in meats, have been linked to elevated cholesterol and other unfavorable disease risk profiles. Interestingly, saturated fats themselves may not be responsible for many of the adverse health effects that they have been associated with, but rather the processing of meats may be at fault. Consuming preservatives in processed meats, such as sodium, nitrates and nitrites, may raise blood pressure and impair insulin response.

Most research shows a sliding scale of improved health outcomes from increased plant intake with decreased meat intake. Completely eliminating meat and dairy products may not be necessary for good health, however, as they can be part of a healthy eating pattern. Choosing whole foods over processed foods also is an important strategy for maximizing the health benefits from any diet plan.

Going Vegetarian

As mentioned, the term “vegetarian” can mean a lot of things to a lot of people, as vegetarians exhibit diverse dietary practices. Here are some suggestions for making the shift toward a plant-based diet:

• Gradually reduce animal food intake, as this method is easier to adopt and adhere to than more extreme recommendations, such as completely excluding all animal products.
• Start with a few plant-based meals per week and build toward creating a sustainable habit.
• Incorporate a theme into your meal planning. For example, you could start with “Meatless Mondays” and gradually expand the idea to include two to three days per week. Or try “Vegan Before 6,” which is an approach that allows meat and animal products only at dinner.
• Consider sustainability in how it applies to the longevity of a diet plan. For example, following a semi-vegetarian eating plan is likely to be easier to maintain than a strict vegan plan over a long period of time.
• Understand that healthy eating is a lifestyle, not a 30-day challenge.

The Wrong Way to Follow a Vegetarian Diet

As with any diet plan, there are healthy and less-healthy versions of vegetarianism, and being any type of vegetarian by name does not guarantee the health benefits discussed earlier.  Soda, cookies, French fries, macaroni and cheese, and sugary cereals are all vegetarian foods. Certainly, a vegetarian diet can be high in calories, sugar, preservatives and unhealthy fats. Also, strict vegetarian diets can omit certain nutrients, primarily omega-3 fatty acids, calcium, vitamin D, iron, zinc and vitamin B12. Constructing a healthy vegetarian diet includes meal planning and preparation to avoid missing out on important nutrients.

A plant-based diet may also need to include fortified foods (i.e., vitamins and minerals added to the product) and potentially supplementation. Vitamin B12, specifically, is only obtainable through animal foods or dietary supplements. Eggs and milk, however, contain B12; thus, a lacto-ovo-vegetarian will have fewer nutrient gaps to fill than a vegan.

Summary

Consuming adequate amounts of vegetables and fruits is, in fact, the strongest correlate with reduced disease risks, particularly CVD (USDA, 2015). A healthy diet (including or excluding meat products) should include more vegetables and fewer processed foods. Regardless of which dietary approach you follow, make healthy eating a lifestyle that you can follow for years to come.