VN: Types and Diversity of Vegetarian Diets (2009)

Citation:
 
Study Design:
Class:
- Click here for explanation of classification scheme.
Quality Rating:
Research Purpose:
  • To review the research on the nutritional status and nutritional risks of vegetarian children
  • To assess the impact of different types of vegetarian diets on nutritional adequacy in children.
Inclusion Criteria:

None stated.

Exclusion Criteria:

None stated.

Description of Study Protocol:
  • Selection of research: Method for identifying research not provided
  • Design: Narrative review
  • Blinding used: Not applicable
  • Intervention: Not applicable
  • Statistical analysis: None.
Data Collection Summary:

Dependent Variables

  • Nutritional adequacy
  • Nutritional risks.

Independent Variables

  • Type of vegetarian diet (e.g., vegan, lacto-vegetarian, lacto-ovo-vegetarian)
  • Age of child.
Description of Actual Data Sample:
  • Initial N: 61 articles included in the bibliography. Not all were research articles or research directly on vegetarian children.
  • Age: Children (birth to 18 years)
  • Ethnicity: Not applicable.
Summary of Results:

Vegetarian Diets in Children

Jacobs and Dwyer state that the makeup of vegetarian diets for adults may not be appropriate for design of vegetarian diets in children.

Additionally, different types of vegetarian diets pose their own set of challenges: lacto-ovo-, lacto- and vegan.

Jacobs and Dwyer cite research indicating that restricted vegetarian diets may present nutritional difficulties in children.

Studies Cited:

Truesdell DD, Acosta PB. Feeding the vegan infant and child. J Am Diet Assoc 1985; 85: 837-840.

Johnston PK. Getting enough to grow on. Am J Nursing l984; 84: 336-339.

Dietz WH, Dwyer JT. Nutritional implications of vegetarianism for children. In: Suskind RM, ed. Textbook of pediatric nutrition. NewYork: Raven Press, 1981; 179-188.

S. Brown PT, Bergan JG. The dietary status of”new” vegetarians. J Am Diet Assoc 1975; 67: 455-459.

Trahms CM, Feeney MC. Evaluation of diet and growth of vegan, vegetarian and non-vegetarian preschool children. Fed Proc l977; 33: 67S (abstr).

Vegetarian diets vary widely depending on race, culture, location and religious beliefs. Jacobs and Dwyer identify a range of issues that affect the nature of vegetarian diets:

  • The health, philosophical or religious beliefs associated with some types of vegetarianism
  • Acceptance of enriched, refined or processed foods
  • Use of vitamin-mineral supplements
  • Avoidance of alcohol and tobacco
  • The eaters’ integration into and use of the health-care system.

The authors provide a table that describes some characteristics of various vegetarian diets (Table 1; p. 12).

TABLE 1: Types of Very Restrictive Vegetarian Diets

Types of Vegetarianism

Group

Supplements

Use of Healthcare System

Other Characteristics

Vegan-like

 

 

 

 

 

Zen macrobiotics

No

No

Avoid sugar, smoking permitted

 

Rastafarians

No

No

Avoid salt, preserved foods, additives, alcohol

Marijuana is used in a religious ritual

 

British vegan

Yes

Yes

 

 

Black Hebrews

No

No

 

 

The Farm

Yes

?

 

 

Fruitarians

?

?

 

Vegetarian

 

 

 

 

Lacto-

Yogic (some)

?

?

Restrictions vary with sect

 

Hindu immigrants

?

Yes

Avoid Western cheeses; adults fast regularly

 

Hare Krishmas

No

?

Use natural, organic foods; avoid tobacco and alcohol

Lacto-ovo-

Seventh-day Adventists

Yes

Yes

Avoid tobacco, alcohol, highly processed foods

 

Anthroposophics

Yes

?

Avoid tobacco, alcohol

 

Yogic (some)

?

?

Restrictions vary by sect

Risks for Different Age Groups of Children

The authors describe the risks and benefits of a vegetarian diet according to the age group of children:

Early Infancy

Jacobs and Dwyer state that healthy infants who are breast-fed by women who eat adequate vegan and vegetarian diets thrive in early infancy. They point out that the most essential requirement during infancy is that sufficient milk be supplied to meet the infant’s needs. So, they recommend a demand-type breast-feeding schedule with frequent ad libitum suckling.

The authors report a study that found that for the first six months the breast milk from lacto-ovo-vegetarian mothers was similar to that of omnivores in minerals, trace elements, lactose and total fat, but that the fatty acid concentration differed.

Studies Cited:

Sanders TAB, Purves R. An anthropometric and dietary assessment of the nutritional status of vegan preschool children. J Hum Nutr 1981; 35: 349-357.

Dwyer JT, Andrew EM, Berkey C, Valadian I, Reed RB. Growth in “new” vegetarian preschool children using the Jemss-Bayley curve fitting technique. Am J Clin Nutr 1983; 37: 818-827.

Dwyer JT, Andrew EM, Valadiam I, Reed RB. Size, obesity and leanness in vegetarian preschool children. J Am Diet Assoc 1980; 77: 434-437.

Dwyer JT, Palombo R, Thorne H, Valadian I, Reed RB. Preschoolers on alternate life-style diets. J Am Diet Assoc 1978; 264-270.

Shull MW, Reed RB, Valadian I, Palombo R, Thorne H, Dwyer JT. Velocities of growth in vegetarian preschool children. Pediatrica 1977; 60: 410-417.

Finley DA, Lomnerdal B, Dewey KG, Grivetti LE. Breast milk composition: fat content and fatty acid composition in vegetarians and non-vegetarians. Am J Clin Nutr 1985; 41: 788-800.

Later Infancy (6-18 months)

The authors state that the weaning period is a time of nutritional vulnerability. Because energy intakes are likely to be inadequate after four to six months, the authors say that breast-feeding can and should be extended. It is also important to supplement with vitamin D and iron (36, 39, 40).

Because growth of the child begins to fall off in late infancy and because this is a time of transition from breast-feeding to table foods, the risks of inappropriate diets and poor nutritional status during this period are considerable. At this age very restrictive, unplanned diets are inappropriate.

Deficiencies of these types of diets include calories, protein, vitamins D, B12, calcium, phosphorus, zinc and iron.

Energy intake: Because the infant’s stomach capacity is limited at this age (one to three year-olds can only consume approximately 200 to 300ml at each meal) children fed vegetarian diets high in fiber, complex carbohydrates and water, but low in caloric density may be at risk of inadequate intake of calories. The authors say that increasing intake of cereals, nut butters and legumes while limiting intake of fruits, vegetables and gruels may help alleviate the problem (2, 7, 44).

Protein: The bioavailability of amino acids and nitrogen may be decreased by dietary fiber, by food processing and storage and by inadequate energy intake. In particular, lysine, methionine and threonine intakes may be inadequate (45). The authors say that it is necessary to combine foods high in lysine, but low in the sulfur-containing amino acids such as legumes, with foods high in methionine and threonine and low in lysine such as grains.

Vitamin D: Deficiency rickets is a particular risk for the infant on a restrictive type of vegan diet. To avoid vitamin D deficiency rickets, the authors recommend that the vegetarian infant be given vitamin D fortified milk or formula, a vitamin D supplement, supplementary foods containing vitamin D and receive adequate exposure to sunlight (2, 3, 7).

Vitamin B12: Vitamin B12 deficiency is rarely reported in the literature, but it and other vitamins may also be in short supply, especially in vegans.

Vitamin B6: Adequate B6 intake is another cause of concern in vegans. Plant sources of vitamin B6 include whole grains, legumes and green leafy vegetables. The bioavailability of the vitamin, however, may be severely limited by the presence of pyridoxine glycoside, one form of vitamin B6.

Studies Cited:

Truesdell DD, Acosta PB. Feeding the vegan infant and child. J Am Diet Assoc. l985; 85: 837-840.

Johnston PK. Getting enough to grow on. Am J Nursing l984; 84: 336-339.

Sanders TAB, Purves R. An anthropometric and dietary assessment of the nutritional status of vegan preschool children. J Hum Nutr 1981; 35: 349-357.

Whitehead RG. Nutritional aspects of human lactation. Lancet 1983; 1: 167-169.

Vyhmeister IB, Register UD, Sommenberg LM. Safe vegetarian diets for children. Pediatr Clin North Am 1977; 24: 203-210.

Acosta PB. Availability of essential amino acids and nitrogen in vegan diets. Am J Clin Nutr 1988; 48 (suppl): 868-874.

Preschool Age (18 months to five years)

The preschooler’s nutritional needs per unit of weight are less than those in early infancy. The effects of a high-bulk vegan diet continue to be negative for children between 12 and 35 months of age.

Strict macrobiotic or vegan diets may put preschoolers at risk for deficiency states.

  • Sporadic cases of rickets and megaloblastic anemia have been reported among vegans
  • Intakes of vitamin D, riboflavin, and vitamin B12 are especially likely to be below recommendation in unsupplemented diets that exclude the use or very strictly limit the amounts of Vitamin D-fortified milk
  • It is difficult to provide adequate intakes of calcium, zinc and iron with a vegan-like diet, but the inclusion of appropriate plant sources of these minerals and vitamin D-fortified milk products and supplements may offset deficiencies. Bioavailability may also be compromised.

Measurements of growth among vegan-like vegetarians may still be depressed during these years. During the preschool years, some catch-up growth may occur among vegan children whose early growth has been depressed. Adequate food must be provided for catch-up growth to occur.

Children following well-planned, less-restrictive vegetarian diets that include milk products usually meet their nutritional needs. Lacto-ovo-vegetarian diets tend to be lower in bulk and pose fewer problems during weaning.

Studies Cited:

Dwyer JT, Andrew EM, Berkey C, Valadian I, Reed RB. Growth in “new” vegetarian preschool children using the Jemss-Bayley curve fitting technique. Am J Clin Nutr 1983; 37: 815-827.

Dwyer JT, Andrew EM, Valadiam I, Reed RB. Size, obesity and leanness in vegetarian preschool children. J Am Diet Assoc 1980; 77: 434-437.

DwyerJ T, Dicta WH, HassG, Suskind R. Risk of nutritional rickets among vegetarian children. Am J Dis Child 1979; 133: 134-140.

Dwyer JT, Palombo R, Thorne H, Valadian I, Reed RB. Preschoolers on alternate life-style diets. J Am Diet Assoc 1978; 264-270.

Shull MW, Reed RB, Valadian I, Palombo R, Thorne H, Dwyer JT. Velocities of growth in vegetarian preschool children. Pediatrica 1977; 60: 410-417.

van Staveren WA, Dhuyvetter JHM, Bons A, Zeelen M, Hautvast JGA. Food consumption and height/weight status of Dutch preschool children on alternative diets. J Am Diet Assoc 1985; 85: 1,579-1,584.

Curtis JA, Kooh SW, Fraser D, Greenberg ML. Nutritional rickets in vegetarian children. Can Med Assoc J. 1983; 128: 150-152.

Grade School Age (Five to 11 years)

Jacobs and Dwyer report that at the time of this article, no new studies were identified on the nutritional status of children five to 11 years. They point out that the grade school years represent a time of gradual, steady growth and nutritional risks are lower during this time. However, even during this period, the vegan must take special care to consume adequate calories, vitamin B12, calcium, zinc and iron.

Adolescents (12 to 18 years)

The authors state that the pubertal growth spurt represents a period of significant increases in nutritional needs for energy, protein, calcium, phosphorus, iron,  zinc and vitamin A to accommodate growth (50).

Jacobs and Dwyer say that an appropriate vegetarian diet can accommodate the needs described above, but very restrictive vegetarian or vegan diets may need supplementation in calcium, iron, zinc and vitamins B12 and D. They add, however, that in their opinion, it is extremely difficult if not impossible to consistently meet zinc RDA on an unsupplemented vegan or even lacto-ovo-vegetarian diet, since plant foods that contain  zinc are often high in fiber and phytates, which render the zinc unavailable.

Iron status is a concern for all teenagers because of rapid growth of tissues and the increase in blood volume and for females because of menstrual flow (51). It was found that intakes for both groups were low, but the vegetarians had somewhat higher intakes than did the omnivores. While hemoglobin and hematocrit values were within normal limits and were similar between omnivores and vegetarians, iron nutriture as measured by serum ferritin levels, was lower in the vegetarians.

Benefits of a Vegetarian Diet During Childhood

Finally, the authors point out some possible benefits of a vegetarian diet during childhood and adolescence.

  • There is decreased incidence and prevalence of some chronic degenerative diseases among children on vegetarian diets
  • The development of atherosclerosis begins in childhood (56) and elevated serum total cholesterol and blood pressure were shown to be positively and significantly related to atherosclerotic lesions. An SDA-type lact-ovo-vegetarian diet during childhood appears to lead to low levels of serum lipids.
  • Vegetarian diets or moderate non-vegetarian diets may also be of advantage in avoiding obesity.

 

Author Conclusion:
  • An appropriate vegetarian diet can adequately provide for each phase of growth in the child. The nutritional needs at each stage vary.
  • In general, it is difficult to achieve normal growth following a vegan-like diet unless care is taken to ensure that the diet is sufficient in calories, protein, vitamin B12, vitamin D and iron.
  • Well-planned lacto-ovo- and lacto-vegetarian diets for children on the other hand, can provide adequate nutrition. Further, they may help establish healthful patterns that will continue through all the stages of life.
Funding Source:
University/Hospital: Tufts University School of Medicine
Reviewer Comments:
  • Narrative review contained no indication of how studies were selected, nor the relative quality of the different pieces of research
  • No assessment of the overall status of the evidence.
Quality Criteria Checklist: Review Articles
Relevance Questions
  1. Will the answer if true, have a direct bearing on the health of patients? Yes
  1. Will the answer if true, have a direct bearing on the health of patients? Yes
  2. Is the outcome or topic something that patients/clients/population groups would care about? Yes
  2. Is the outcome or topic something that patients/clients/population groups would care about? Yes
  3. Is the problem addressed in the review one that is relevant to dietetics practice? Yes
  3. Is the problem addressed in the review one that is relevant to dietetics practice? Yes
  4. Will the information, if true, require a change in practice? Yes
  4. Will the information, if true, require a change in practice? Yes
 
Validity Questions
  1. Was the question for the review clearly focused and appropriate? Yes
  1. Was the question for the review clearly focused and appropriate? Yes
  2. Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described? No
  2. Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described? No
  3. Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased? No
  3. Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified andappropriate? Wereselectionmethods unbiased? No
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible? No
  4. Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methodsspecified,appropriate, andreproducible? No
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? No
  5. Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? No
  6. Was the outcome of interest clearly indicated? Were other potential harms and benefits considered? Yes
  6. Was the outcome of interest clearly indicated? Were other potential harms and benefits considered? Yes
  7. Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described? No
  7. Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently acrossstudies and groups? Was thereappropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described? No
  8. Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included? Yes
  8. Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels ofsignificance and/or confidence intervals included? Yes
  9. Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed? No
  9. Are conclusions supported by results with biases and limitations taken into consideration? Are limitations ofthe review identified anddiscussed? No
  10. Was bias due to the review's funding or sponsorship unlikely? Yes
  10. Was bias due to the review's funding or sponsorship unlikely? Yes