12 adolescence Flashcards
Adolescence
-period of rapid changes in
- physiological
- psychological
- cognitive functions
Variability in
- growth rate
- development
- activity level
- timing of growth spurt
Growth spurt
- peak height velocity
- highest nutritional needs
- 20% of height+ 50% of weight
- 2X higher incorporation of Ca, Mg, Zn, Fe into bone
Boy
- finish later
- higher peak high velocity
- longer prepubertal growth
- sexual maturation begins early than height
- adult man higher height
- growth continue after sexual maturation
- greater growth spurt, prolonged, intense, later year
- Testosterone–> sig. increase in bone and muscle, loss of fat
- adult male 150% LBM vs. female
- 2X muscle mass
nutrition requirement
energy + protein
- physiological or maturational age to deter
- intensity and extent of growth spurt
- gender and body composition
- timing of pubertal growth spurt
SMR
Sexual maturation rating
- dtandard used clinically to describe the stage 1-5 (10-17yr) of development
- based on development of 1st and 2nd sexual characteristics
- same sequence, same order, timing varies
SMR 1
- rapid
- no discernible sexual change
bone mass and skeletal growth
- Girl SMR 2
- Boy SMR 3-4, 40% peak bone mass
Girl
- Pubertal growth spurt–> tanner breast stage 3
- sexual maturation earlier
- environmental factors
- Menarche 1yr after breast
- later menses with longer period of growth
- sexual maturation stops, linear growth stop
- 1/3 skeletal mineral accumulated in 3-4 yr agter onset of puberty
- delayed puberty/ 2nd amenorrhea–> decrease BMD as adult
- height velocity decrease, fat resume
- 2X faster in girl
Peak weight accumulation
Female–> before peak height velocity
Male–> same time as peak height velocity
Lean body mass
Female–> SMR 3-4, after height complete
Male–> 5, after stature complete
Hormone
growth hormone
testosterone
adrenal androgen
Bone mass
- adolescence–> achieve bone mass–> protect from osteoporosis
- high intake of Ca (45% deposited in adolescence)
Final stage of skeletal growth
- epiphyses fuse at end of long bone
- main portion of bone and growth in stature ceases
weight
Male–> LBM/muscle increase (2x), muscle higher metabolism rate
Female–> drop, more fat,
Female onset for menses
critical BM 47.8kg,
17% body fat composition
Max fat loss and muscle mass increase in upper arm
time of peak height velocity
Androgens + estrogens
bone mineral deposition
Eating behaviour
External factors
sociocultural, neurochemical, psychological
- food availability–> developing country
- skipping meals
- parents practices
- peer pressure
- mass media
- fast food–> low nutrient and fibre, high sugar+ sodium
- snacks (25% kcal)
- food fads
- poor nutrition knowledge
- personal experience (drug, alcohol)
- smoking–> Nicotine decrease food intake, increase wt loss
- -> ease hunger signal–> nutrients deficiency
- -> quitting increase 10lb
Internal
eating behavior
- physiological changes
- body image
- Self-concept
- personal value and belief
- food preference
- dieted, nutrient deficiency, life-long risk of weight cycling –> greater fat tissue than lean
- 10% drop in WT–> 15% drop in BMR
- eating disorder 20X higher in female, culture pressure
- independence
- irregular eating habits
adolescence obesity
20% environmental+ 80% genetic
Exercise
aerobic adaptation, stronger heart+ muscle, increase max. oxygen uptake–> increase efficiency of O2 utilizes by lung–> increase heart circultion
interdisciplinary approach of obesity
diet+ exercise+ behaviour modification+ psychological support
Calorie restriction
linear growth restriction+ nutritional dwarfism–> growth failure, short stature, delayed puberty
nutrition rehabilitation
2/3 catch up growth
Anorexia Nervosa diagnostic criteria
- no know medical or psychiatric illness
- 15-20% of below expected WT
- intense fear of wt gain (even when underweight)
- malnutrition–> no >=3 mensural cycle
- disturbed self-image
2 type
- restrictive–> no purging
2. binging/ purging–> binging followed by vomiting, diuretics, laxative
eating disorders
anorexia nervosa
bulimia
binging
DSM-5
- restriction energy intake–> sig, low wt
- intense fear of gain wt
- undue influence of body wt or shape on self-evaluation, or denial current low wt
health risk of anorexia
mortally 2-20% due to multiple organ organ system
- electrolyte imbalance–> cardiovascular abnormoalities (arrhythmia, irregular heart beat, inefficient heart pumping due to weak heart muscle)
- GI system disorder (inflammatory disease, diarrhea ,fever, cramping)–> decrease estrogen
- Amenorrhea–> loss body fat
- decrease blood pressure
- kidney dysfunction
- irreversible brain damage–> wrenches’ encephalopathy–> death
- muscle wasting–> low LBM–> decrease muscle function–> decreased BMR
- defective thermoregulation
- starvation mode: dry skin, hirsutism, thin brittle dry hair+ hair loss, dehydration+ edema
- growth cessation
- premature bone loss+ osteopenia–> low bone mass, increase risk of osteoporosis
recovery
slow+ gradual infusion of calories
osteoporotic risk of anorexia
- loss of protein and mineral salts–> low bone mass+ strength
- continues or relapses, 20yr–> permanent bone loss
- increase cortisol, low IGF-1 and leptin–> slow down bine formation
only effect treatment of osteoporosis
wt gain–> increase bone mass (when period return)
Avoid
exercise
hypoestrogenism
why
puberty delay or 2nd amenorrhea –> low BMD despite weight-bearing exercise
Bulimia
binging> 1/week followed by purging, 3 month
binging
- eating in a discrete period of time, excessive amount of food, lack of control
- compulsion eating not response to hunger
purging
regular self-induce vomiting, laxative, diuretics, enema
bulimarexia
non-purging type
- exercise or fasting after binging
- fasting+ depleted nutritional state
health risk of bulimia
- Irritation and infection of esophagus, salivary glands
- erosion of teeth and dental caries
- electrolyte/ fluid / water and pH imbalance–> hypokalemia–> severe, dehydration
- loss of acidic hydrogen via stomach acid
- increase risk of sub-clinical malnutrition
- XS bicarbonate, alkaline pH
- low bp, low urine, dry mouth, confusion
- perception problem: broken eye syndrome, think bigger than real
Hypokalemia
defect of K
muscle weakness, twitching, cramping
eating disorder
delayed sexual maturation+ deteriorating linear growth
BED binge eating disorder
- loss of control
- marked distress over binge
- at least 1/week for 3mo
- >=3 of following
- eating more rapidly than normal
- eating until feeling uncomfortably full
- eating large amounts of food when not physical hungry
- eating alone b/c being embarrassed by eating too much
- disgusted with oneself, depressed, guilty b/c overeating
Tx of eating disorder in teens
- specific approaches towards psychology of teens
- social acceptance–> good physical appearance–> good nutrition
- no severe energy restriction
- treat clinical depression, alcohol, cigarette abuse
- anti- depressant抗抑郁药 (wants high fat+ sweet)
- diet counselling
- no exercise
- replace distorted belief regarding wt and food intake
- work together with teen
- emphasize importance of breakfast
