Vegetarian Diet vs. Other Diets: Which Is Best?

Those who aspire to eat healthfully often reduce their intake of meat and other animal products to boost wellness. Meat, particularly red meat and processed meat are associated with reduced heart and other diseases. And when you reduce your intake of animal products, you add more room for more fruits, vegetables, and grains. Some people also choose a vegetarian diet to support animal rights or for environmental reasons.

If you're considering different options, there are a myriad of plant-based eating plans to choose from. The vegetarian diet is just one of them.

See how the vegetarian diet compares to similar diets, such as the pescatarian diet, the flexitarian diet, the vegan diet, and the Mediterranean diet. Then see how each diet compares to federal nutritional guidelines provided by the U.S. Department of Agriculture (USDA) to determine the best eating plan for you.

USDA Recommendations

There are different types of vegetarian diets. The most common type is the lacto-ovo vegetarian—someone who avoids animal products and seafood but consumes dairy and eggs. Ovo-vegetarians eat eggs but avoid dairy, meat, and seafood. Lacto-vegetarians consume dairy but avoid eggs, meat, and seafood.

Within each of these types of vegetarian diets, food choices might vary substantially. Even researchers have confirmed that some vegetarian diets are very healthy while others are not. For that reason, it can be tricky to compare this eating plan to other diets.

However, the USDA and the U.S. Department of Health and Human Services included a Healthy Vegetarian Dietary Pattern as part of their 2020—2025 Dietary Guidelines for Americans. The guide provides recommendations for the intake of various food groups such as green leafy vegetables, starchy vegetables, legumes and beans, soy products, and others.

It can be helpful to see how this food plan compares to federal guidelines that are provided for the general public.

Food Groups

Current USDA nutrition guidelines suggest consuming a variety nutrient-rich vegetables, fruit, grains, fat-free or low-fat dairy products, protein sources, and oils. The guidelines also suggest that Americans limit saturated fats, trans fats, added sugars, and sodium.

On the lacto-ovo vegetarian and lacto-vegetarian diet, you can easily consume foods in all food groups, since dairy products are a great source of protein. However, those who adhere to a ovo-vegetarian diet would not consume foods from the dairy group. Nut- and rice-based milk alternatives are excluded from the dairy group despite that they may contain some amount of calcium. The USDA has determined that these alternatives do not offer the same level of nutrition as dairy products or fortified soy beverages.

A healthy vegetarian diet is likely to be low in saturated fat in accordance with the USDA nutrition guidelines. Most of the saturated fat consumed in the standard American diet comes from meat and full-fat dairy products and these foods are generally eliminated or reduced in a vegetarian eating plan.

If you are a strict vegetarian, you might also limit your intake of processed foods which may contain butter or other animal products. Many times these foods contain added sugars, excess sodium, and even trans fat—which all Americans are advised to limit according to USDA recommendations.

Nutrients

It is possible to get adequate amounts of important nutrients on a vegetarian diet. Adhering to the USDA's recommendations for vegetarians will help you reach recommended intakes. But there are certain nutrients that are sometimes lacking in vegetarian diets that are not well-rounded.

Calcium

USDA guidelines suggest that we consume 1,000—1,300 milligrams of calcium per day. Studies investigating the dietary intake of semi-vegetarians have found that most reach that target. However, ovo-vegetarians who do not consume dairy should fill up on calcium-rich foods such as green leafy vegetables, white beans, pulses, sesame seeds, and dried fruits like figs that are rich in the nutrient. Calcium-fortified milk alternatives such as almond milk as well as soybeans, tofu, almonds, and certain whole grains also provide calcium.

Vitamin B12

Vitamin B12 helps to regulate metabolism and is found primarily in animal and seafood products. The USDA recommends that adults consume 2.4 micrograms (mcg) of B12 per day. Eggs, some dairy products, and some fortified breakfast cereals provide the vitamin. However, the USDA states that supplementation may still be needed for those who follow a vegetarian diet and recommends consulting with a healthcare provider to determine whether supplementation is necessary.

Zinc

A well-planned vegetarian diet can provide adequate zinc through plant-sources such as whole grains, tofu, tempeh, legumes, nuts and seeds, fortified breakfast cereals and dairy products. Still, some researchers have found that vegetarians often have lower levels of zinc. They also note, however, that vegetarians tend to adapt to these lower levels through increased absorption and retention of the mineral.

Fats

Current USDA guidelines suggest that we consume less than 10% of our daily calories from saturated fats—often found in meat and dairy. Health experts also suggest that we replace these less healthy fats with polyunsaturated and monosaturated fats.

Vegetarians are likely to naturally reduce their intake of saturated fat by eliminating meat from their diets, and if they consume plant-based oils and foods such as nuts and seeds they are likely to get adequate amounts of healthy fat.

Protein

USDA guidelines suggest that adults consume 10–35% of their total calories per day from protein. It is typical for vegetarians to consume less protein than non-vegetarians, but the intake may still be adequate. Foods such as tofu, nuts, seeds, legumes, and grains are good sources of the macronutrient. The USDA also suggests that vegetarians consume eggs and soy products to meet the recommended intake.

Calories

Studies have shown that those following vegetarian diets consume fewer calories than those following omnivore (unrestricted) diets. But your caloric intake is not restricted on a vegetarian diet. There are no caloric requirements and food portions are not limited.

Unless you are trying to lose weight, there is no reason to count calories unless it helps you with weight management. Even so, many people who switch to a vegetarian diet lose weight simply by eliminating meat and increasing their intake of low-calorie nutrient-dense foods like fruits and vegetables.

But you may still want to check your calorie intake to make sure that you reach and maintain a healthy weight. To estimate your total calorie needs for the day, you can use a calorie calculator. This calculator takes your age, sex, goals, and activity level into account to determine the best number for you.

Variety

A vegetarian diet is more restrictive than a conventional American diet. Many people who shift to the eating style find it challenging to eliminate meat (and sometimes eggs or dairy) from their meals. However, a vegetarian diet may inspire you to eat a wider variety of nutritious foods.

Without meat on your plate, a vegetarian who eats healthily may include a variety of protein-rich grains or soy-based foods like tofu, tempeh, or edamame. And since vegetables will likely play a greater role in your daily diet, you may be inspired to try new varieties.

However, with the increasing popularity of vegetarian processed foods and meat alternatives, it is still possible to eat a diet with less variety and lower overall nutritional quality. Some plant-based processed foods are convenient, but are also high in fat, sodium, and added sugar.

Similar Diets

There are other plant-based eating plans that are somewhat vegetarian. In fact, some consider the pescatarian diet, flexitarian diet, and the vegan diet to be variations of a vegetarian diet. If you are thinking about a dietary change to boost your health, consider these other diets that are often recommended for improved wellness.

Vegan

A vegan diet is similar to a vegetarian diet in that meat and seafood are not consumed. But vegans also do not eat eggs, dairy, or any food that contains any animal by-product including honey.

General nutrition: Researchers have compared the vegan diet to other plant-based diets using the Healthy Eating Index and other nutrient intake comparisons. They concluded that even though vegetarian diet fares well, the vegan diet is most healthy. But it is also the lowest in calcium and is the most restrictive.

Protein, calcium, and vitamin intake may be lower on a vegan diet because dairy foods and eggs are not consumed. Vitamin supplements (especially vitamin B12) are often recommended on this plan. And vegan diets may also be lacking in zinc, iron, and iodine, vitamin D. Overall, caloric intake on a vegan diet is usually the lowest among plant-based diets when measured in studies.

Health benefits: A vegan diet is associated with many of the same health benefits as a vegetarian diet, including a lower risk of cardiovascular disease, diabetes, and hypertension. Some studies have even shown that even when less healthy food choices are made, vegans tend to be at reduced risk for cardiovascular disease.

Weight loss: Because eliminating meat, dairy, and all animal-based products helps to cut fat and calories from your diet, a vegan diet is more likely to be the lowest in calories and most effective for weight loss, according to research. However, since plant-based processed foods are becoming more common, it is still possible to overeat on a vegan diet.

Sustainability: Many people find the vegan diet very hard to maintain. However, there are some studies indicating that adherence rates don't vary substantially between vegan, vegetarian, flexitarian, pescatarian, and omnivore diets for weight loss.

Your ability to stick to the plan may depend on your reasons for choosing the diet, the support you get from family and friends, and your willingness to experiment with new foods and recipes.

Flexitarian

On a flexitarian diet, you eat primarily according to vegetarian guidelines. However, people who follow the flexitarian lifestyle occasionally eat meat and seafood.

General nutrition: The flexitarian diet provides similar nutrition to a vegetarian diet. But the occasional inclusion of meat and seafood can help increase your intake of protein and vitamin B12 and make plant-based eating more balanced.

Health benefits: Because a flexitarian diet is primarily a vegetarian diet, those who follow this eating style are likely to gain the same benefits, including increased heart health and a lower risk for many chronic diseases.

Weight loss: If weight loss is your goal, the flexitarian diet and the vegetarian diet are likely to be similarly effective. Eating an occasional meat or seafood meal is not likely to change the calorie intake of a vegetarian diet enough to make a difference. But since adherence is a key issue when trying to lose weight, the flexitarian diet may be slightly more successful.

Occasional meat-based meals may help you stick to the diet longer for both weight loss and healthy weight maintenance.

Sustainability: While studies have found little variation between plant-based diets (including this one) when it comes to adherence, many experts suggest that a flexitarian diet is more sustainable simply because it allows for occasional indulgences. Traveling, eating out, and socializing with friends are likely to be easier on this plan.

Pescatarian

If you follow a pescatarian diet, you eat primarily plant-based foods but include fish and seafood in your diet as well.

General nutrition: Using the Healthy Eating Index, researchers scored the pescatarian diet about the same as the vegetarian and flexitarian diet. However, when using a different healthy eating scale based on the Mediterranean diet, this eating style scored higher than both the vegetarian diet and flexitarian diet.

The emphasis on fish consumption helps to increase not only your protein intake but also your intake of healthy fats, including omega-3 fatty acids.

Health benefits: You're likely to gain the same health benefits on this diet as you would on a vegetarian diet, but you may enjoy a few additional advantages if you consume fish that are higher in omega-3 fatty acids, such as salmon, mackerel, or some types of tuna. These fatty acids help to maintain healthy arteries, lower LDL cholesterol and decrease both triglyceride levels and blood pressure.

Weight loss: As compared to a standard American diet, this eating plan is likely to be more effective for weight loss. As compared to a vegetarian diet, it is likely to be just as effective. The consumption of fish may increase your calorie intake slightly (depending on the type you choose) but you may also increase satiety and adherence.

Sustainability: If you are currently a regular fish eater, this diet is likely to be sustainable. But for some others, it may be less so. Not everyone is comfortable cooking fish on a regular basis. Fresh fish tends to have less fat, sodium, and other unnatural ingredients (when compared to breaded or processed fish).

Mediterranean

A Mediterranean diet includes all food groups recommended by the USDA. Animal products are consumed, but minimally. The focus is on vegetables, grains, nuts, seeds, and plant-based healthy oils.

General nutrition: This diet aligns with nutritional guidelines provided by the USDA. In fact, the document provides specific recommendations for those following a Mediterranean diet.

Foods that are higher in saturated fat (dairy and meat) are minimized and foods that boost health (whole grains, vegetables) are encouraged. But since animal products and dairy are still consumed in small quantities, calcium, protein, and vitamin levels are less likely to be compromised.

Health benefits: The Mediterranean diet has been widely studied and is associated with a wide range of health benefits including a lower risk of heart disease, cancer, and other chronic diseases.

Weight loss: Many researchers have evaluated the Mediterranean diet's effectiveness when it comes to losing weight. Several have found the eating plan to be effective for weight loss (as effective as comparable low-fat diets) and others have found that while it may not boost weight loss substantially, it can help to prevent weight gain over time.

Sustainability: Along with the flexitarian diet, the Mediterranean diet is a highly sustainable diet when compared to other more rigorous plant-based diets, such as the vegan diet and the vegetarian diet. No foods are off-limits on this plan. Rather, healthy, whole foods are emphasized and less healthy foods are minimized.