Vegetarian and vegan diets
The benefits of plant-based diets
Following a vegetarian diet — one that is composed mainly of plant foods — is an excellent way to increase the amount of plant-based food in your diet. Vegetarian and vegan diets also offer health benefits which include a decreased risk of heart disease, high blood pressure, cholesterol, stroke, kidney disease, dementia, obesity, cancer, diabetes and digestive disorders. These benefits have been linked to the higher levels of fiber, vitamins, minerals and antioxidants and the lower levels of cholesterol and saturated fat in plant foods. A vegetarian diet is often more affordable than a meat-centered diet.
Nutrition recommendations and concerns
A vegetarian diet, like an omnivore diet (i.e., includes all kinds of food), can be more or less healthy depending on the choices a person makes. Many junk foods, such as chips, cookies, candy and soda are vegetarian. Consuming these in large amounts will result in a poor diet. Canada's Food Guide can be used by vegetarians and vegans to guide their diet. Vegetarians should make food choices that address any nutritional challenges of their particular type of vegetarianism.
Because there are some nutrients present in animal foods that are not available (or are less abundant) in plant foods, a vegetarian diet may have nutritional challenges. Vegans avoid all animal products so they face the greatest challenges. Semi-vegetarians occasionally eat meat, so they face the least challenges. The main nutritional concerns for vegetarians are:
- Calories: In general, plant foods are less calorie dense than animal foods. Therefore, vegetarians need to eat a greater volume of food to meet their calorie needs.
- Vitamin B12: This vitamin is found only in animal foods. Depending on the extent to which a vegetarian excludes animal foods from their diet, they may have to find alternative sources of the vitamin. Some foods such as cereals are fortified with vitamin B12. Check the food label to identify if a food has been fortified. If a person’s diet excludes all animal foods, they may need to take a supplement, such as a multivitamin, to meet their daily vitamin B12 needs.
- Calcium: Calcium is less abundant in plant foods than in animal foods. Vegans and vegetarians who don’t consume dairy products will need to include plant sources rich in calcium in their diet. They may also consider a calcium supplement.
- Iron: The iron found in plant foods is absorbed less readily than that in animal foods. Vegetarians should make sure to include iron-rich plant foods in their diet such as beans and dark leafy vegetables. A daily multivitamin will also supply iron.
- Protein: All plant foods — with the exception of soy and quinoa — lack sufficient "essential" amino acids that are needed to make protein in the human body. Eating a variety of plant foods will provide a full complement of essential amino acids.
Other nutritional challenges — particularly for vegans — are vitamin D, zinc and iodine intake.
Vegetarian and vegan resources
If you wish to learn more about vegetarian and vegan diets, there are many websites with comprehensive information such as:
- Vegetarian Resource Group
- Vegetarian Nutrition
- The Vegan Society
- Thousands of vegetarian recipes
- Vegetarian/vegan Food Pyramid [PDF]
An excellent (although somewhat scientific) resource is the Position of the American Dietetic Association: Vegetarian Diets.