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Vegetarianism for Adolescents

Adrianne Dula


Information on Vegetarianism and Adolescence


A vegetarian is defined as one whose diet consists of primarily or wholly of vegetables and vegetable products.  Although this definition is widely accepted, there are considerable variations among vegetarian diets.  These variations have been given different terms in order to elucidate the foods that a person includes in their diet.  A lacto-ovo vegetarian is an individual whose diet is based on grains, vegetables, fruits, legumes, seeds, nuts, dairy products, and eggs.  It excludes meat, fish, and fowl.  A vegan’s diet is similar to that of the lacto-ovo vegetarian with the additional exclusion of eggs, dairy, and other animal products (American Dietetic Association, 1997).   The adoption of a vegetarian diet can be influenced by religion, ethical issues, or health/weight loss issues.  Each vegetarian is different in what they choose to eat and why they have made that decision to restrict their diet.

            Decisions are primarily made by others until a person in an adolescent.  The onset of adolescence brings a wave of individuality along with a newfound freedom to make individual decisions.  Many teens opt to make the decision to become a vegetarian.  This decision can be based on their peer’s influence, scientific knowledge, family values, or even the pressure from society to become thin and fit.  This time period in a person’s life is marked by rapid change in the body as well as its freedoms.  The years between the ages of thirteen and nineteen are times of especially rapid physical growth and change causing an individual’s nutritional needs to be exceptionally high during these years.  Vegetarian adolescents must maintain a varied diet including fruits, vegetables, plenty of leafy greens, whole grain products, nuts, seeds, and legumes (Mangels, Reed. 2001).  This varied diet must be maintained to achieve the balance intake of vitamins and minerals which are essential for the energy requirements placed on the body at this time of increased growth and change in the teenager’s life.

            Understanding that the energy and nutrient demands are significantly increased in adolescence, it has been a concern that this is not an optimum time period to adopt a vegetarian diet.  The restriction of any foods is bound to result in a decrease in energy and nutrient intake and this could bring numerous harmful effects to the growing body of an adolescent.  There are arguments supporting both sides of this issue.



General Health Claims


Numerous claims are made supporting every diet that exists, the majority of them professing the magical results that will be experienced regarding weight loss and health.  Although the sole purpose of the vegetarian diet is not to lose weight, this diet is no exception. Many doctors are adamant advocates of the vegetarian diet, Dr. Michael Klaper developed a video where he describes how vegetarianism has changed his life (Klaper, Micheal, 2002).


My cholesterol level fell sharply, my blood pressure, which had been slightly elevated, fell to normal levels, but most impressive to me, I had almost a 24 pound spare tire around my waist which I could not get rid of even though I was running five miles a day.  Within 12 weeks that 24 pounds of fat melted right away.  I found myself walking up a nice, lean, light body, even though I was eating tremendous amounts of Italian food, Chinese food, East Indian food, Thai food, potatoes, and pastas.  I certainly did not deprive myself.


Although this sounds like amazingly similar to a late night infomercial for a magic bullet diet pill, there are omnipotent claims that can be found on the web.  The most popular being that a vegetarian diet can lower risks for heart disease, increased blood pressure, some forms of cancer, and obesity.  There are countless websites which serve as support groups and resource networks for vegetarians, including some specifically aimed at teens.    

In addition to the commercial websites, The American Dietetic Association (ADA) has published their position on a vegetarian diet.  They state that vegetarian diets offer disease protection benefits because of their lower saturated fat, cholesterol, and animal protein content and often higher concentration of folate (which reduces serum homocysteine levels), antioxidants such as vitamins C and E, carotenoids, and phytochemicals (American Dietetic Association, 1997).  The ADA even went as far as saying that studies indicate that vegetarians often have lower morbidity and mortality rates from several chronic degenerative diseases than non-vegetarians.



Calcium and Protein Information


Despite the obvious support from the ADA, there are various concerns regarding insufficient nutrient content in a diet which eliminates meat.  The intake of calcium and protein are prominent nutrients which are subjects of concern.  Calcium is a mineral used to build bones.  Since the adolescent years are a time when bone density is determined, this time period is especially critical for adequate calcium intake.  It should be noted that vegans may have lower calcium needs than non-vegetarians (American Dietetic Association, 1997).  Dr. Michael Klaper provides the reasoning for this; “The high protein content of animal products, when it is metabolized, leaves a lot of acids in the body, sulfur, and sulfuric acids.  These acids have many detrimental effects, the chief one being that these acids help calcium dissolve out of the bones” (Klaper, Michael, 2002). 

            Dr. Klaper’s claim is actually supported by an article found in the journal Nutrition.  This article states that although the quantity of plant food required to meet the recommended daily allowance for calcium from a plant-based diet could be impractical, the low protein content of a vegetarian diet and presence of phytoestrogens in those who consume soy may have a protective effect against osteoporosis (Rajaram, Sujatha & Sabate, Joan, 2000).    Good sources of calcium for vegetarians who want to avoid cow’s milk include: tofu processed with calcium sulfate, green leafy vegetables including collard greens, mustard greens, and kale, and calcium-fortified soy milk and orange juices.

            This presents the issue of inadequate protein consumption in a vegetarian’s diet.  Proteins are the currency of the body’s genetic system.  There are 20 essential amino acids which the body does not manufacture; therefore they must be included in the diet.  It is a common thought that animal products are the only source of these compounds.  On the contrary, as long as the energy needs of a vegetarian are met, plant sources of protein can provide an adequate amount of the essential amino acids.  There is some buzz concerning “complementary proteins” meaning that certain proteins must be eaten together in order for them to be absorbed, but the ADA disagrees.  Research suggests that complementary proteins do not need to be consumed at the same time and that consumption of various sources of amino acids throughout the day will ensure adequate nitrogen retention (American Dietetic Association, 1997).


Iron Information

Text Box: Sources: USDA Nutrient Data Base for Standard Reference, Release 12, 1998. Manufacturer's information.
In addition to protein and calcium, iron is another factor which is commonly thought to be lacking in the vegetarian diet.  Principally for adolescent females following menarche, the recommended daily allowance for iron, 15mg as opposed to the RDA for males, 10mg, is extremely important to be obtained to maintain proper health.  Iron is an essential nutrient because it is the central part of hemoglobin which carries oxygen in the blood.  Iron is found in two forms, heme and non-heme iron.  Heme iron makes up forty percent of the iron in meat, poultry, and fish is well absorbed.  Non-heme iron, sixty percent of the iron in animal tissue and all of the iron in plants, is less well absorbed.  Non-heme iron is also more sensitive than heme iron to both inhibitors and enhancers of iron absorption.  Dietary fiber inhibits the absorption of non-heme iron by binding to it and reducing its bioavailability.  The absorption of non-heme iron can also be inhibited by calcium phosphate, phylates, bran, or polyphenols in tea, coffee, and soybean products (Huang, Cheng, & Su, 1999).  Therefore it is thought that vegetarians may be at a greater risk for iron deficiency. 

            In fact, this is not the case.  Recent surveys of vegans and vegetarians have shown that iron deficiency anemia is not more common in vegetarians than in the general population (American Dietetic Association, 1997).    There are numerous reasons for this phenomenon.  Initially, foods eaten by vegans and vegetarians are commonly superior to animal-derived foods considering iron content in relation to calories.  For example, one would have to eat 340 calories of sirloin streak to get the same amount of iron as found in 100 calories of spinach.  An additional reason for the satisfactory iron status of vegetarians is that vegetarian diets are high in vitamin C.  Vitamin C is a powerful enhancer of non-heme iron absorption, adding vitamin C to a meal increases the non-heme iron absorption up to six-fold which makes the absorption of non-heme iron as good or better than that of heme iron (Hallberg, L., 1981).  In fact, high iron containing foods are also significant sources of vitamin C, resulting in generous levels of iron absorption.





































Vitamin B12 Information


            Vitamin B12 is essential for cell division and blood formation.  This presents an obstacle for vegetarians because plant foods do not contain this vitamin unless they have been contaminated by microorganisms.  Vitamin B12 is an essential vitamin, although it is only necessary in small quantities.  In addition to the requirement being so low, vitamin B12 is stored and recycled in the body so symptoms of deficiency may be delayed for years (American Dietetic Association, 1997).  Vitamin B12 deficiency is a very serious problem leading to irreversible nerve damage.  Although the body does make vitamin B12, it does not appear to be an adequate amount to prevent vitamin B12 deficiency. 

            It is a common thought that vitamin B12 is made by animals, but in fact it is found in animal products because they have eaten the microorganisms which make the vitamin.  These same vitamin B12 producing organisms are now cultured and sprayed on breakfast cereals and added to soy milk and burgers (Klaper, Michael, 2002).  Vitamin B12  can also be found naturally in spirulina, sea vegetables, tempeh, and miso (American Dietetic Association, 1997).



Decreased Energy Content


            Vegetarian diets have been found to provide smaller amounts of energy than the diets of omnivores (Meirelles, Veiga, & Soares, 2000).  This fact puts adolescents who adopt a vegetarian diet at risk for insufficient intake of nutrients and energy.  It has been verified that the vegetarian diet could interfere with the stature gain of pre-adolescents.  This is probably due to the delay of the beginning of puberty.  However, the stature of vegetarians is not impaired because they continue growing until the end of adolescence and they reach a final height which is similar o those of omnivorous girls (Meirelles, Veiga, & Soares, 2000).

            As stated previously, the vegetarian diet is found to contain less energy than the standard diet.  This presents the appeal of this lifestyle to those who are focusing on loosing weight.  The onset of adolescence is usually a prime time for girls to begin the widespread dieting cycles which occupy the lives of countless women.  Adolescent vegetarians may be at a greater risk than their peers for unhealthy weight control behaviors.  The vegetarian diet is a known way to accomplish developmental tasks and loose weight (Perry, McGuire, Neumark-Sztainer, & Story, 2001).  Vegetarian diets are somewhat more common among adolescents with eating disorders than in the general adolescent population therefore, dietetics professionals should be aware of young clients who greatly limit food choices and who exhibit symptoms of eating disorders.  However, recent data suggest that adopting a vegetarian diet does not lead to eating disorders (American Dietetic Association, 1997).   



Conclusion and Food Guide Pyramid


Text Box:  Source: American Dietetic Association Position Paper on Vegetarianism 1997
More and more teenagers are choosing not to eat meat, fish, or poultry.  They are often faced with pressures from parents who are concerned for their health.  The most frequently asked questions have been addressed with the indispensable concept of variety being the omnipotent answer.  The key to a healthy vegetarian diet is variety while a teenaged vegetarian’s needs are the same as those of any other teenager.  The nutritional needs are high during these years and the nutrients which are most important are calcium, protein, iron, and vitamin B12.  Please refer to the Food Guide Pyramid for Vegetarian Meal Planning provided here to achieve the variety necessary.  Using this as guidance in meal planning, vegetarian diets are appropriate and healthful choices for adolescents (American Dietetic Association, 1997). 




























Literature Citations


Position of the American Dietetic Association: Vegetarian Diets (1997)


Mangels, Reed (2002).  Vegetarian Nutrition for Teenagers.  The Vegetarian Resource Group 2002  (


Klaper, Michael (2002).  Excerpts transcribed from the “Nutrition For Optimum Health” Video


Rajaran, Sujatha (2000).  Health Benefits of a Vegetarian Diet.  Nutrition 16(7/8): 531-2.


Huag YC, Lin WJ, Cheng CH, Su KH (1999).  Nutrient Intakes and Iron Status of Healthy Young Vegetarians and Non-Vegetarians.  Nutrition Research 19:663.


Hallberg L: Bioavailability of dietary iron in man. Ann Rev Nutr 1981; 1: 123-147.


Meirelles, C., Veiga, G., & Soares, E. (2001).  Nutritional Status of Vegetarian and Omnivorous Adolescent Girls.  Nutrition Research 21:698-702.


Perry, C., McGuire, M., Neumark-Sztainer, D., & Story, M. (2001).  Characteristics of Vegetarian Adolescents in a Multiethnic Urban Population.  Journal of Adolescent Health 29:406-416.




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