Adolescence is a period of rapid physical, emotional, intellectual, and social maturation. To support this growth, teenagers need extra calories, calcium, and iron, and sufficient protein. Teenage eating habits are influenced less by parents and family, and more by peers, media messages, and body image issues.
Following a period of slow growth during late childhood, the teenage growth rate is as rapid as that of early childhood. By the end of adolescence, teens attain most of their adult height and weight.
Although adolescence spans a period of five to seven years, teens do most of their growing during an 18-24 month period called the "growth spurt." To support this rapid growth, teenagers need to consume lots of calories and other nutrients.
During adolescence, teens go through puberty, a process that involves total body maturation and the development of adult sexual function. The body composition of both females and males changes during adolescence.
Before puberty, females have approximately 19% body fat, which increases to about 22% after puberty. Males maintain body fat percentage of approximately 15%, but during adolescence, males gain two times more muscle mass than females.
The Dietary Reference Intakes for teenagers appear in the table below. The following nutrients are of special importance.
Teenagers need lots of calories to support rapid growth. Girls need approximately 2200 calories, while boys need 2500-2900 calories.
Protein is also necessary for physical growth, and should account for 15-20% of total calories. However, protein deficiency is quite rare in the United States, so protein consumption need not be overemphasized unless the teen is following a vegetarian or vegan diet.
Many teens consume too much fat. Like adults, the diets of teenagers should contain no more than 30% of calories as total fat and 10% of calories as saturated fat. Teens should limit high-fat junk foods, and include foods containing essential fatty acids including walnuts, flaxseeds, pumpkin seeds, sunflower seeds, and cold water fish.
Nearly half of all skeletal growth occurs during adolescence. As a result, large amounts of calcium are needed during the teenage years. To ensure proper absorption and utilization of the calcium, vitamin D is also needed.
Teenage males and females have increased requirements for iron. For boys, the increase in muscle mass that occurs during adolescence is accompanied by greater blood volume. In females, iron is lost during the monthly cycle.
Large amounts of the B vitamins thiamin, riboflavin, and niacin are needed to meet the energy requirements of teens.
|Nutrient||M 9-13||F 9-13||M 14-18||F 14-18|
|Vitamin A (mcg RE)||600||600||900||700|
|Vitamin D (mcg)||5||5||5||5|
|Vitamin E (mg alpha-TE)||11||11||15||15|
|Vitamin K (mcg)||60||60||75||75|
|Thiamin (mg)||900 mcg||900 mcg||1.2||1.0|
|Riboflavin (mg)||900 mcg||900 mcg||1.3||1|
|Niacin (mg NE)||12||12||16||14|
|Pantothenic Acid (mg)||4||4||5||5|
|Vitamin B6 (mg)||1||1||1.3||1.2|
|Vitamin B12 (mcg)||1.8||1.8||2.4||2.4|
|Vitamin C (mg)||45||45||75||65|
The desire for independence is a defining characteristic of the teenage years. One of the ways that teenagers assert their independence is through their dietary choices. They eat more meals away from home, and often have money to purchase meals and snacks on their own.
The eating habits of the family take on less importance, while the influence of peers and media messages increases. Adolescence is also a time of dietary experimentation. For example, many teens follow vegetarian or vegan diets.
Issues related to body image also affect dietary choices. According to the Youth Risk Behavior Study of 1990, few adolescents are satisfied with their appearance. 34% of the females surveyed reported feeling "too fat" and 44% of female students said they were trying to lose weight. The most popular methods for losing weight are exercise and skipping meals.
In addition, teens often use vomiting as a way to control their weight. More alarming, this survey found that many of the students who feel fat are well within a normal weight range for their height.
The dietary choices of teens may also be impacted by various health conditions, most notably anorexia nervosa, bulimia nervosa, and obesity.