Research on the dietary intake of adolescent vegetarians from several countries indicated that although the patterns differ somewhat among countries, adolescent vegetarians tended to consume fewer dairy products, snack foods and sweets than omnivorous adolescents. They tended to consume more vegetables than their omnivorous peers. Outside the US and Canada, adolescents who considered themselves vegetarian tended to eat more chicken or fish than their omnivorous counterparts.

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.

Studies show that disordered eating is common among self-defined adolescent and young adult vegetarians. However, the two studies that differentiate among types of vegetarians indicate that this is not true of all adolescent and young adult vegetarians.

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.

Studies from a limited number of Western countries indicate that adolescent vegetarians or semivegetarians may be more likely than adolescent omnivores to meet general national standards for some nutrients. However, they may also have lower intake than national standards for micronutrients such as iron, zinc and vitamin C. Because of the limited nature of the studies available, other nutrients, such as B₁₂, may also be of concern.

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.

Studies consistently find that animal rights and welfare and environmental concerns are most often listed as primary motivations behind adolescent vegetarianism in Western societies. Although health concerns are also cited as motivations for vegetarianism, they are less important in this population.

• Grade I means there is Good/Strong evidence supporting the statement;
• Grade II is Fair;
• Grade III is Limited/Weak;
• Grade IV is Expert Opinion Only;
• Grade V is Not Assignable.
• High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
• Moderate (B) means we are moderately confident in the effect estimate;
• Low (C) means our confidence in the effect estimate is limited;
• Very Low (D) means we have very little confidence in the effect estimate.
• Ungraded means a grade is not assignable.