Vegetarian Diets: Nutritional Adequacy

The days of thinking of a vegetarian diet as a diet that few people adhere to are behind us. It is vastly becoming a popular way of life. Most airlines and restaurants now offer vegetarian meals. More and more people are turning towards vegetarian diets as a way of life. Some people choose a vegetarian diet as a way to eat healthy and achieve their health goals. For others the choice to become a vegetarian is a selective choice to avoid consuming food and food products from animal origin. There are three common types of vegetarian diets:

  • Vegan or Total Vegetarian-only foods of plant origin are included in this diet plan.
  • Lacto-Vegetarian-includes all plant products and dairy products but no meat or eggs.
  • Lacto-Ovo Vegetarian-includes all plant products, dairy products and eggs.

When comparing the Recommended Dietary Allowances with the lacto and lacto-ovo vegetarian diets these diets are nutritionally adequate with some exceptions. You can get enough protein from a total vegetarian diet as long as the variety and amounts of food consumed are adequate. Concerns are:

  1. A potential deficiency of the total vegetarian diet is calcium especially for females at all ages, teenagers and young adult males. A viable option for ensuring adequate calcium intake is a calcium-fortified milk alternate available in supermarkets.

  2. Other nutrients of concern in the total vegetarian diet are B12, riboflavin, iron, vitamin A, vitamin D, high quality protein and total caloric intake.

  3. It is difficult for the total vegetarian diet to provide the energy needs for children due to the volume of food required. Ideally all vegetarians should be seen by a registered dietian to assess the adequacy of their diet and determine the need for further vitamin and or mineral supplementation needs.

Food Groups and Serving Sizes for Vegetarian Diets

Food Group Daily Servings Serving Size
Breads, grains, cereals
(50% whole grain)
  • 1 slice bread
  • 1 oz ready to eat cereal
  • 1/2 cup cooked cereal, rice or pasta
  • 6-in tortilla
  • 1 small roll or muffin
  • 1/2 bagel or English muffin
Legumes 1-2
  • 1/2 cup cooked dry beans, lentils, peas, limas etc. 
  • 1/2 cup tofu, soy products or meat analogs
Vegetables, dark-green and green leafy vegetables 3-5
  • 1/2 cup cooked vegetables 
  • 1 cup raw leafy vegetable or salad 
  • 3/4 cup vegetable juice
Fruits 2-4
  • 1 medium piece of fruit
  • 1/2 cup chopped, cooked or canned fruit
  • 1/4 cup dried fruit
  • 3/4 cup fruit juice
Nuts and Seeds 1-2
  • 1 oz almonds, walnuts, seeds etc.
  • 2 Tbs. peanut butter, almond butter, tahini
Milk, yogurt and/or cheese 2-3
  • 1 cup lowfat milk or yogurt
  • 1.5 oz lowfat cheese
  • 1/2 cup part skim ricotta
Milk alternatives (soy milk) and tofu See patterns in Lacto-Ovo Diet
  • 1 cup soy milk fortified with calcium/vitamin D and vitamin B12 
  • 1 cup tofu
Fats and Oils See patterns in Lacto-Ovo Diet
  • 1 tsp. oil, margarine, or mayonnaise
  • 2 tsp salad dressing
  • 1/8 Avocado
  • 5 olives
Sugar See patterns in Lacto-Ovo Diet
  • 1 tsp. sugar, jam, jelly, honey, syrup etc.

Suggested Meal Patterns for Lacto-Ovo Vegetarian Diets

Food Group  Daily Servings
1600 Kcal/Day

2200 Kcal/Day

2800 Kcal/Day

Bread, grains, cereals

6 9 11

Legumes, plant proteins

1 2 3
Vegetables 3 4 5
Fruits 2 3 4
Nuts, seeds 1 1 1
Milk, yogurt, cheese 2-3 2-3 2-3
Eggs 1-2 1-2 1-2
Added fats and oils 2 4 6
Added sugar 3 6 9


According to the USDA, there is no difference between a “portion” and a “serving.” See Answer

Suggested Meal Patterns for Vegan Diets

Food Groups Daily Servings
  1600 Kcal/Day 2200 Kcal/Day 2800 Kcal/Day
Breads, grains, cereals 8 10 12
Legumes, plant proteins 1 2 3
Vegetables 2 3 4
Dark Green Leafy Vegetables 2 2 2
Fruits 2 4 6
Nuts, seeds 1 1 1
Fortified soy drinks
and tofu
2-3 2-3 2-3
Added fats and oils 2 4 6
Added sugar 3 6 9


  1. U.S. Department of Agriculture, Agricultural Research Service, Dietary Guidelines Advisory Committee, 1995. Report of the dietary guidelines advisory committee on the dietary guidelines for Americans, 1995, to the Secretary of Health and Human Services and the Secretary of Agriculture, 58pp.
  2. Haddad EH. Development of a Vegetarian Food Guide. American Jour of Clinical Nutr, 59(5): 1248S-1254S, May 1994.


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