Update of nutrition guidelines for the teen: trends and concerns.

Sociocultural influences are known to affect adolescent eating patterns and behaviors. Some teens reject a meat-based diet to become vegetarians; others take up dieting to lose weight or develop an eating disorder. Teens require increased nutrients to provide for the accelerated growth that takes place during these years. Nutritional deficiencies in adolescence can lead to loss of height, osteoporosis, and delayed sexual maturation. Sports also play an important role in many teens' lives. The desire to excel can lead to increased training and prolonged periods of dieting. Disordered eating, amenorrhea, and osteoporosis describe the "female athlete triad." Although more frequently seen in girls, boys who participate in sports that have an emphasis on size and weight such as wrestling and body building are also at risk for subclinical eating disorders. This paper discusses issues surrounding restrictive and nonrestrictive food patterns of adolescents and their nutritional consequences.