Overview of Adolescent Development

Question 1

What are the characteristics of the critical period of adolescence?

Answer 1

Changes in body composition (BF, FFM, Height)
Changes in diet, PA, sedentary behaviors
Sleep
Sports and specialized motor skill development
Emerging identity and role
Mental health

Question 2

What is the body composition characteristics during adolescence?

Answer 2

FFM increases
BF increases
Grow taller

Question 3

What are some diet changes experienced during adolescence?

Answer 3

Males: 2800 kcal
Females: 2000 kcal
Decreased consumption of fruit, veggies and milk
Increased consumption of carbonated drinks

Having family meals= healthier meals in adulthood

Fewer family meals = increased risk of obesity

Question 4

What are the changes in physical activity during adolescence?

Answer 4

PE: mandatory in elementary but not always in HS
Significant gender shift through adolescence

International review of PA levels of 10-17 years old:
Boy>girls
PA declines with age

Question 5

What is the trend in screen time?

Answer 5

Increasing screen time over the years
in 2014 only 31% of adolescents got <2 hours of screen time/day

7.8h/day average screen time

Question 6

What is the trend in terms of adolescent fitness?

Answer 6

Decline in fitness over the years in adolescents

Question 7

What happens when an adolescent gets less than 9h of sleep/night

Answer 7

Decreased leptin levels
Increased ghrelin levels
Increased BMI, increased appetite and increased food intake

Question 8

What are the characteristics of adolescent motor development?

Answer 8

Specialized movement abilities
Transition stage (7-9): movement exploration
Application stage (11-13): children choose what to pursue
Lifelong utilization stage (14+): refinement
Application to specialized sport skills:
- significant sub-population of adolescents engage in highly structured competitive sport and less structured recreational sport
- Positive social and health implications for this group

Question 9

Characteristics of Puberty.

Answer 9

Accelerated somatic growth
Maturation of primary sexual characteristics
Appearance of secondary sexual characteristics:
- pubic and axillary hair
- female breast development
- male voice changes
Menstruation and spermatogenesis begin

Question 10

What are factors affecting puberty?

Answer 10

Genetic
Biological
Stress
SES
Nutrition and diet
Exercise
% body fat
Chronic illness

Question 11

What is the pubertal onset in girls?

Answer 11

Around 11-13 years old
Age of menarche (1st menstrual cycle)
Obesity associated with earlier menarche
“excessive smartphone screen time linked to earlier puberty onset”

Question 12

What is the pubertal onset in boys?

Answer 12

Hit puberty approx 2 years after girls
Obesity is associated with later puberty

Question 13

What are the Tanner stages in girls?

Answer 13

Tanner stage 1: no signs of puberty
Tanner stage 2-3: any breast enlargement, pubic or axillary hair
Tanner stage 4-5: If all of the following:
Started periods with signs of pubertal development

Question 14

What are the Tanner stages in Boys?

Answer 14

Tanner stage 1==> if all of the following:
High voice and no signs of pubertal development

Tanner stage 2-3 ==> if any of the following:
Slight deepening of voice
Early pubic or axillary hair growth
Enlargement of testes or penis

Tanner stage 4-5 ==> if any of the following:
Voice fully broken
Facial hair
Adult size of penis with pubic and axillary hair

Question 15

What is the hormonal control of puberty?

Answer 15

Hypothalamic- pituitary- gonadal (HPG) axis
Hypothalamus releases:
- gonadotropin releasing hormone (GnRH) ==>
FSH and LH

FSH+LH–> activate the gonada –> estrogen/progesterone and testosterone

Question 16

What are the hormonal changes that happen due to puberty?

Answer 16

Increased GH, liver lipolysis, FFA
Decreased insulin sensitivity (about 30%)

Females: estrogen increases fat deposition (peripherally)

Males: testosterone increases FFM

Question 17

What happens to fat cell size and number in girls during puberty?

Answer 17

Higher number of fat cells and bigger fat cells in girls in preparation for potential pregnancy

Question 18

What are the differences between sexes in terms of fat distribution and FFM?

Answer 18

During maturation, adolescents:
increased FFM (males> females due to testosterone)
Females increased %BF peripherally
Males increased body fat mass (subcutaneous and visceral in abdomen)

In adulthood
Women: >total and subQ adipose tissue
Men: < fat mass but increased cardio-metabolic risk

Question 19

Characteristics of Delayed Onset of Puberty.

Answer 19

“the absence of secondary sexual characteristics by age 13 in girls and 16 in boys”

Constitutional growth delay (inherited, temporary, delay in growth)

Underlying medical condition
Not considered a medical concern
Severely delayed/absent puberty can be treated with HRT

Question 20

What is Precocious Puberty?

Answer 20

” the appearance of secondary sexual characteristics before the age of 8 in girls 9 in boys” 1 in 5000 to 10000
Central precocious puberty: pattern and timing proceed normally, but starting too soon (could be tumor, hypothyroidism related)

Peripheral precocious puberty: Less common, congenital or acquired genetic mutations –> idiopathic
Could be an issue with testicles, ovaries, adrenal or pituitary glands

Isosexual PP: consistent with genetic and gonadal sex of child
Contra-sexual PP: Feminisation or virilisation

Question 21

What are the precocious puberty risk factors?

Answer 21

Genetics: family history of PP
Females>males
Racial backgrounds: african-american children more
Obesity
Exposure to sex hormone: creams and ointments
Medical condition: abnormal production of androgens
Radiation Therapy to CNS
Exposure to blue light

Question 22

What are the complications of PP?

Answer 22

Short height: appear tall vs peers, but bones mature sooner resulting in shorter stature

Social and emotional issues: Social self-consciousness about the changes occurring in their bodies