Physical Changes In Teenagers Affecting Dietary Needs

As your child transitions into the teen years, you may notice his appetite increasing. This isn't surprising considering the considerable growth and development that occurs during adolescence. In fact, only infants experience more physical growth than teenagers during the lifespan, according to University of Missouri professors Mary Story, Ph.D, RD and Jamie S. Stang, Ph.D, MPH, RD. Meeting the appropriate recommendations for calories, macronutrients and other nutrients are essential for meeting developmental milestones.

Physical Changes

Nutrient needs during the teen years are greater than in any other time in life. Not getting adequate nutrition could affect normal growth, development and sexual maturation. From the school-age years through adolescence, minors grow 20 percent taller and 50 percent heavier, according to registered dietitian Roberta Larson Duyff, author of the "American Dietetic Association Complete Food and Nutrition Guide" released in 2011. As children enter puberty, differences in dietary needs between girls and boys become more pronounced.

Calories

Minors need more calories as they transition from childhood to adolescence. How much of an increase in caloric intake the Institute of Medicine recommends depends on gender and activity level. Boys ages 14 to 18 need 2,000 to 3,200 calories per day; an intake of 1,800 to 2,400 calories daily is advised for girls in the same age group. Not getting enough calories could inhibit proper growth and delay puberty, according to the 2005 publication "Guidelines for Adolescent Nutrition Services."

Macronutrients

Macronutrient needs do not change between the ages of 4 and 18. Minors in this age group should get 10 to 30 percent of their daily calories from protein, which is needed for building lean body mass and height growth. Carbs are the main source of energy for the body and should provide the bulk of calories in the diet at 45 to 65 percent. Fats are also a source of energy and are needed for normal growth and development; they play roles in immune function and blood coagulation, as well. Teens should get no more than 25 to 35 percent of calories from fat and limit consumption of saturated fats.

Iron

The mineral iron is needed to transport oxygen through the bloodstream. Growing teens need more iron to accommodate the physical changes associated with adolescence. The recommended daily intake jumps from 8 mg for children to 11 mg and 15 mg for boys and girls, respectively, at ages 14 to 18. Girls are at particular risk for low levels due to iron loss during menstruation.

Other Highlighted Nutrients

Calcium is also vitally important because of rapid bone growth in teens. Almost half of peak bone mass develops during the teen years, and low calcium intake could lead to future bone conditions including osteoporosis. Adolescents need 1,300 mg a day through age 18. Low zinc levels affect development, as well. Males, in particular, could have delayed growth and sexual maturation due to low zinc. Girls and boys ages 14 to 18 should get 9 mg and 11 mg, respectively, each day.

Physical Changes in Teenagers Affecting Dietary Needs