“I’m a vegetarian. What are good sources of vegetarian protein, and how do they differ from animal protein?”

Many people are adopting vegetarian diets for health, ecological, religious, spiritual, economical and ethical reasons. There are multiple versions of ‘vegetarianism’. For instance, some consider themselves vegetarian but eat eggs, therefore making them ‘ovo-vegetarian’. Others may eat eggs, fish and poultry but no red meat classifying them as ‘ovo-pesco-pollo-vegetarian’. Strict vegetarians do not eat any animal products. If strict vegetarian diets contain a variety of plant foods they can meet a person’s nutritional needs, but poor choices can make it difficult to meet all nutrient needs, including protein. Excellent sources of protein in the vegetarian diet include nuts, seeds, legumes (black beans, garbanzo beans, kidney beans, lentils, pinto beans), grains (rice, wild rice, whole wheat breads, cereals, pastas), soy (soy milk, tempeh, tofu), and meat substitutes (vegetarian burger, veggie hot dog, soy cheese and other meatless products).

The significant difference between plant protein versus animal protein is the essential amino acid profile. Amino acids are the building blocks of protein in the body. There are 20 amino acids, 9 of them are essential, meaning the human body does not make them and requires them from the diet. Animal protein contains all 9 essential amino acids, thus making it a complete protein. Plant proteins are considered incomplete proteins because they are missing one or more of those essential amino acids. However, by mixing plant protein sources in the diet throughout the day, all 9 essential amino acids can be consumed. For instance, combining rice and beans in a meal complement each other because grains provide the essential amino acids that legumes lack and vice versa. Soy is one plant exception. Soy is considered a complete protein. Overall, protein needs for vegetarians may differ. Although there is no research stating vegetarians have higher protein needs, it has been suggested that vegetarians may need to consume approximately 10% more protein than non-vegetarians to account for the lower digestibility of plant proteins compared with animal proteins.

Other differences between food sources of plant and animal proteins include varying nutrient content. Animal protein sources often contain cholesterol and are typically higher in total fat and saturated fat. Excessive intake of these nutrients has been associated with increased risk of cancer and heart disease. Plants are cholesterol free, relatively low in fat and saturated fat, and are high in fiber thus reducing the risk for cancer and heart disease. There is also disparity in vitamin and mineral content and availability among plant and animal food sources. For example, animal protein has more iron and it is more available for absorption per serving compared to iron found in plant proteins. Additionally, vitamin B₁₂ is found only in animal products with fermented soy products being an exception.

In summary, vegetarian diets can meet protein needs when careful, well-educated choices are made on a daily basis.

By Marlia Braun, PhD, RD and MealWell Sports Nutrition Advisor