Adolescent (11-21 Years of Age) Nutrition
Adolescence is the period of life from 11 to 21 years of age. There is profound biological, emotional, social and cognitive development as a child grows into adulthood. During this important stage of development physical, emotional and cognitive maturity is reached, and there is development of personal identity and a value system that is unique and separate from parents and other family members.
This can be a challenging time for an adolescent as she struggles for personal independence, yet recognizes the need for economic and emotional family support. Adolescents are also adjusting to their new bodies that have changed in shape, size, and function.(1) Keep these challenges in mind when viewing the adolescent as being difficult or irrational. Your adolescent is dealing with a lot!
Because of the dramatic physical growth and development during this stage, there is an increased need for energy (calories from food), protein, vitamins and minerals.(1) Unfortunately at this stage the struggle for independence often leads to health compromising eating behaviors like excessive dieting/caloric restriction and following fad diets, skipping meals, and using unconventional dietary supplements that may cause more harm than good.(2) With guidance, your adolescent can channel their struggle for independence into healthy behaviors like eating a healthy diet, participating in physical activities, and living a healthy lifestyle overall.(1)
During early adolescence, puberty occurs. Sexual maturation, increased height and weight, accumulation of skeletal mass and changes in body composition are observed. The age of onset, duration and tempo of these events varies greatly within and between individuals. Because of these differences, nutritional intake and needs should be based on biological growth and development rather than on chronological age. “Tanner Stages” (sexual maturation rating or SMR) is used by health professionals to assess pubertal maturation, regardless of chronological age.(1,3) SMR is based on the development of breasts and pubic hair in females, and on testicular, penile and pubic hair development in males.(1,3) Table 1 demonstrates the Tanner Stages of development in females and males.(4)
In females, the first signs of puberty include the development of breast buds and sparse, fine pubic hair around age 8 to 13 years. Menarche occurs 2 to 4 years after the first signs of puberty, and is typically around SMR stage 4. The average age of menarche is about 12.4 years, but it can occur as early as 9 to 10 years of age, or as late as 17 years of age. Girls that are highly competitive athletes (female athlete triad)5, and those who severely restrict caloric intake to limit body fat may detrimentally delay menarche. In girls, 15 to 25% of final adult height will be gained during puberty, and linear growth spurts cease on average by age 16 years in most females. Some females will have small increases in height until about 19 years of age. Caloric restriction can slow or delay linear growth.(1,6)
The first signs of puberty in boys are enlargement of the testes and change in coloring of the scrotum. This occurs typically between the ages of 10.5 to 14.5 years (11.6 years of age is the average). Development of pubic hair is common during SMR stage 2. The average age of spermarche is about 14 years of age in males. Linear growth peaks in velocity in males during SMR stage 4, either coinciding with or following testicular development and the appearance of faint facial hair. On average, peak velocity of linear growth occurs at 14.4 years of age. Linear growth continues throughout adolescence and ceases at about age 21 years in males.(1,6)
Up to 50% of ideal adult body weight is gained during adolescence in both females and males. Body composition changes dramatically in females during puberty. Lean body mass percent decreases, and body fat percent increases. During puberty females can experience a 120% increase in body fat.(7) In order for menarche to occur, 17% body fat is necessary, and then body fat must be at 25% for the development and maintenance of a regular ovulatory cycle.(8) While this gain in body fat in females is normal and required for normal physiologic function, it is often viewed as negative, leading to compromising health behaviors (excessive dieting, restriction, and exercise, and use of diet aids and laxatives for example) that can lead to serious disordered eating and eating disorders.(1)
Peak weight in males coincides with the timing of peak linear growth and peak muscle mass development. Adolescent males may gain an average of 20 lbs per year during peak weight gain.(1) Body fat decreases, and by the end of puberty, males on average have about 12% body fat.(1)
By age 18, more than 90% of adult skeletal mass has been formed.(1) Adequate nutrition during childhood and adolescence is therefore critical to support optimum bone growth and development, where a variety of dietary nutrients are necessary for building bone tissue.(1)
Eating patterns and behaviors of adolescents can be influenced by a variety of factors including peer influence, parental modeling, food preferences, availability, cost, convenience, personal and cultural beliefs, media and body image.(1,9,10,11)
During adolescence, there are dramatic biological changes related to puberty that occur. The development of body image and an increased awareness of sexuality become predominant themes. The dramatic changes that take place can lead to the development of poor body image and unfavorable health behaviors, factors that must be addressed by family members and health practitioners when identified.(1)
Peer influence is strong during adolescence. The need for adolescents to fit in can affect nutritional intake, either adversely or beneficially.(1,11) Males that are late bloomers may be more prone to use anabolic steroids and other supplements to fit in with their peers that have matured faster, and females that are early bloomers may resort to disordered eating and present with poor body image.(1) Female early bloomers also may be more likely to take part in adult-like behaviors, such as smoking, drinking alcohol, and engaging in sexual intercourse.(1)
Talking to your child about the variations in tempo and timing of growth and development, modeling healthful behaviors, and educating them about making healthy nutritional choices can help them navigate this tumultuous time, and develop healthy body image and health related behaviors to last their lifetime.(1)
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- Brown J. Nutrition through the Life cycle 4th ed. Belmont, CA: Wadsworth; 2011.
- Eating disorders in adolescents: Principles of diagnosis and treatment. Paediatrics & Child Health. 1998;3(3):189-192.
- Antiretroviral Therapy for HIV Infection in Infants and Children: Towards Universal Access: Recommendations for a Public Health Approach: 2010 Revision. Geneva: World Health Organization; 2010. ANNEX H, SEXUAL MATURITY RATING (TANNER STAGING) IN ADOLESCENTS. Available from: https://www.ncbi.nlm.nih.gov/books/NBK138588/.
- Tanner, JM. Growth at adolescence 2nd Edition. Oxford, England: Blackwell Scientific Publications; 1962.
- Raj MA, Rogol AD. Female Athlete Triad. [Updated 2017 Feb 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2017 Jun-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430787/.
- National Research Council (US) and Institute of Medicine (US) Forum on Adolescence; Kipke MD, editor. Adolescent Development and the Biology of Puberty: Summary of a Workshop on New Research. Washington (DC): National Academies Press (US); 1999. Available from: https://www.ncbi.nlm.nih.gov/books/NBK224695/doi: 10.17226/9634
- Frisch R.E. Fatness, Puberty, and Fertility The Effects of Nutrition and Physical Training on Menarche and Ovulation. In: Brooks-Gunn J., Petersen A.C. (eds) Girls at Puberty. Springer, Boston, MA; 1983.
- Frisch RE, McArthur JW. Menstrual cycles: fatness as a determinant of minimum weight for height necessary for their maintenance or onset. Science. 1974;185(4155):949-51.
- Videon TM, Manning CK. Influences on adolescent eating patterns: the importance of family meals. Journal of Adolescent Health. 2003;32(5):365-373.
- Wade TD, Lowes J. Variables associated with disturbed eating habits and overvalued ideas about the personal implications of body shape and weight in a female adolescent population. Int. J. Eat. Disord., 2002;32:39–45. doi:10.1002/eat.10054.
- Story M, Neumark-Sztainer D, French S. Individual and Environmental Influences on Adolescent Eating Behaviors. Journal of the American Dietetic Association. 2002;102(3):S40-S51. doi.org/10.1016/S0002-8223(02)90421-9.