Identify the nutrients most often found lacking in the diets of teenagers

Answer 1

The energy needs of adolescents vary greatly, depending on the current rate of growth, gender, body composition, and physical activity. Boys' energy needs may be especially high; they typically grow faster than girls and, as mentioned, develop a greater proportion of lean body mass. An exceptionally active boy of 15 may need 3500 kcalories, or more, a day just to maintain his weight. Girls start growing earlier than boys and attain shorter heights and lower weights, so their energy needs peak sooner and decline earlier than those of their male peers. An inactive girl of 15 whose growth is nearly at a standstill may need fewer than 1800 kcalories a day if she is to avoid excessive weight gain. Thus, teenage girls need to pay special attention to being physically active and selecting foods of high nutrient density so that they will meet their nutrient needs without exceeding their energy needs.

Vitamin D is essential for bone growth and development. Recent studies of vitamin D status in adolescents show that many are vitamin D deficient; blacks, females, and overweight adolescents are most at risk. Adolescents who do not receive enough vitamin D from fortified foods such as milk and cereals, or from sun exposure each day, may need a supplement.

The need for iron increases during adolescence for both females and males but for different reasons. Iron needs increase for females as they start to menstruate and for males as their lean body mass develops. In addition, iron needs increase when the adolescent growth spurt begins, whether that occurs before or after age 14 . Iron intakes often fail to keep pace with increasing needs, especially for females, who typically consume fewer iron-rich foods such as meat and fewer total kcalories than males. Not surprisingly, iron deficiency is most prevalent among adolescent girls. Iron-deficient children and teens score lower on standardized tests than those who are not iron deficient.

Adolescence is a crucial time for bone development, and the requirement for calcium reaches its peak during these years. Unfortunately, many adolescents, especially females, have calcium intakes below recommendations. Low calcium intakes during times of active growth, especially if paired with physical inactivity, can compromise the development of peak bone mass, which is considered the best protection against adolescent fractures and adult osteoporosis.