By: Justin Robinson, MA,RD,CSSD,CSCS,TSAC-F, Human Performanace Dietician, Naval Special Warfare Center
Posted: September 14, 2021
Information presented within is not intended to treat, cure, or prevent any disease or condition.

Vegetarian, vegan, plant-based … all similar terms with some distinct differences. Vegetarian diets usually include all fruits, vegetables, grains, legumes, nuts, and seeds and may include eggs and dairy products. They typically exclude all meats (flesh). Plant-based is an encompassing term for vegan, vegetarian, and semi-vegetarian diets which are defined by the type, amount, or frequency of animal product(s) consumed.

A vegan diet is 100% plant-based and excludes all forms of animal products – meat, eggs, dairy, and by-products. Further, the diet plan is seemingly the polar opposite of the ketogenic diet plan (in both macronutrient profile and diet culture). Advocates of low-carbohydrate, high-fat diets, such as the keto diet, typically spurn the vegan diet, believing that it is nutritionally inferior to other diet plans.

Thus, it is no surprise that debate exists regarding the healthiest and most environmentally sustainable diet plan.

The Dietary Guidelines for Americans promotes plant-based eating, but that does not always mean vegan. The term “plant-based” describes a number of eating patterns that limit or eliminate meat and animal products.


  1. Vegan: Consumes only plant products – does not consume any meat, eggs, or dairy.
  2. Vegetarian: Consumes eggs and/or dairy, but no meat or other animal products.
  3. Pescatarian: Consumes fish and may consume eggs and dairy, but no beef, poultry or game meat.
  4. Semi-Vegetarian: Consumes meat rarely, likely 3-4 servings per month. Occasionally consumes meat (once or twice per week) or excludes all red meat.
  5. Flexitarian: Rarely consumes meat (once or twice per month – typically only when traveling, dining out, or eating at someone else’s house).


  1. Associated with improved cardiovascular function and reduced mortality.
  2. High in fiber, which can support healthy gut function.
  3. High variety of fruit, vegetable, and legume consumption increases antioxidant and phytonutrient intake.
  4. Environmentally friendly.


  1. Potentially void of certain nutrients – particularly B12, iron, zinc, calcium and vitamin D.
  2. Requires extensive meal planning and preparation (as with all strict diet plans).
  3. May not provide enough total calories for athletes or those with high calorie needs.
  4. Restrictive, which can lead to poor overall nutrient intake. Vegan replacement foods (faux meats and cheeses, for example) are often highly processed.

For anyone choosing to follow a vegan diet, they should be aware of common hidden sources of animal products, such as beef/chicken-based broths and soups, butter and milk powder in baked goods, butter and animal fats used in cooking (especially at restaurants), and whey powder in protein shakes and bars.


As with any diet plan, more and less-nutritious versions exist. Soda, cookies, French fries, macaroni and cheese, and sugary cereals are all vegetarian foods. Certainly, a vegetarian diet can be high in added sugar, preservatives, and unhealthy fats, thus plant-based eating does not guarantee health benefits. Also, strict vegetarian diets can omit certain nutrients, primarily omega-3 fatty acids, calcium, Vitamin D, iron, zinc and B12. Constructing a healthy vegetarian diet involves extensive meal planning and preparation.

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


A common criticism of vegan is inadequate protein, as meat provides convenient, dense amounts of protein. Most plant-based foods are, in fact, lower in protein quality and quantity than animal products – 8 ounces of almond milk, for example, contains 1 gram of protein compared to 12 grams from cow’s milk. With proper meal planning, variety of foods, and adequate total calories, however, a vegan diet can supply enough protein. The body makes protein from amino acids, which are prevalent in all foods. Thus, combining foods (beans and rice, for example) can provide sufficient amino acids and protein.


  1. Plant-based diets CAN be healthy. But just because a food or dish is vegan, does not make it nutritious.
  2. Most people would benefit from increasing whole fruit and vegetable intake.
  3. Most people would benefit from slightly decreasing meat and dairy intake.
  4. Consider incorporating a few meatless dishes each week (embrace Meatless Mondays, for example).
  5. A healthy diet (including or excluding meat products) should include more vegetables and fewer processed foods.
  6. Eat what you enjoy – but focus on whole, unprocessed foods macronutrient profiles.
  7. Eat what fuels your training – consume a balance of carbohydrate, protein and fat. Excluding foods or food groups creates an unbalanced diet and could lead to nutrient deficiencies.


Naval Special Warfare Assessment Team