lecture 7: adolescence Flashcards
what are the key messages from adolescent Nutrition 1 - Nutrition on adolescence growth and development - Lancet series
- Time of transformative growth, both undernutrition and obesity affect multiple
physiological systems - A time of unprecedented change in food environments (e.g., with both micronutrient
deficiencies/food insecurity and obesity) - Intergenerational impacts – a period of growth and development with profound
consequence on individual’s health in later life (and health of any potential children) - Adolescent nutrition affect timing and form of puberty
- Nutrition sensitive window to promote healthy growth and reduce risk of obesity later in
life - Scaling up research is needed as is underinvested
describe adolescent physiological development in terms of height and weight
- Over 1.5 – 3-year time span
- Females – 16cm and 16kg
- Males – 20cm and 20kg
- Average height is increasing (nutrition and health, environments and health of the mother)
- Weight is disproportionally increasing
- Growth charts important in monitoring growth
describe adolescent physiological development in terms of sexual maturation
- Five stages of development (Tanner Stages)
- Useful in further understanding nutrition requirements as peak-velocity growth occurs:
- Stages 2 and 3 for females
- Stage 4 for males
describe adolescent physiological development in terms of body composition
- Males – greater muscle development, and proportionately less fat at ~16-18% (testosterone)
- Females – muscle mass continues to develop, though greater fat deposition at ~ 22-26% (oestrogen)
- Link between overweight and obesity in girls and earlier menstruation
describe adolescent physiological development in terms of body skeletal growth
- Period of rapid bone growth due to impact of sex, thyroid and growth hormones
- Full adult statue reached ~17 years for females and ~21 years for males
- Bones are set and are at their longest (and will not change)
- Bones widen and become denser (and continue to increase in density until up to 30years)
- Over half of adult bone mass is laid down in adolescents
describe early adolescence development
- Adjusting to
developing body - Beginning of the
development of
moral concepts - Friends are a
strong influence,
and family are less
influential - Approach to
improving nutrition
should focus on
the now
describe middle adolescence development
- Increased
emotional
independence
from family - Increase in health
risk behaviors - More comfortable
with developing
body - Some financial
independence
describe late adolescence development
- Physical
development near
completion and
cognitive
development close
to adult-level - Better
understanding of
self, beliefs, values - Employed or
tertiary studies - Approach to
improving nutrition
can focus on link
between present
and future
what are the key messages from Adolescent Nutrition 2 – Food choice in transition
(adolescent autonomy, agency, and the food environment) - lancet series
- Dietary intakes during adolescence – foundation for healthy life
- But adolescents are diverse in their dietary patterns/factors that influence food choice
- Unique contextual features that drive dietary intake and food choice
- More evidence and research needed
- Adolescents must be active partners (autonomy and agency) in shaping action
- Food environments are not conducive to healthy food choice
- Need:
- regulation/policy to improve the food environment
- empowering with knowledge/skills and motivation to navigate to a healthy/socially appealing diet.
individual factors influencing adolescent nutrition and diet
- Adolescent brings significant changes in lifestyle, eating behaviours, exposure to environmental
influences - Impact of:
- personal factors (e.g., body image, level of autonomy, preferences…)
- psychosocial factors (e.g., attitudes, beliefs, self-efficacy, mood, mental health…)
- biological factors (e.g., appetite, hunger, taste..)
- Increased susceptibility to food fads, and restrictive diets can lead to habits of skipping and substituting
meals
social factors influencing adolescent nutrition and diet
- Enhance social interaction can lead to influence of others on their decision making
- Social and emotional importance of peers increases
- Adolescents eat ~ 1/3* of meals away from home, hence nutrition influenced by choices made (*Aust source:
Whitney et al., 2022) - Peer influence occurs both in person and online
environmental factors influencing adolescent nutrition and diet
- Physical, economic, social, cultural, political environments influences on adolescent dietary
behaviour - External environmental factors very influential – hence targeted health promotion messages
may aid in improving adolescent food choices - Consumption of discretionary foods (high sugar, high fat) is higher outside of the home e.g.,
school vending machines, retail food outlets, online food delivery apps and services - Adolescent exposure to food messaging and marketing e.g., both physical food environment
and online space (e.g., peer posting, online food advertising…)
what are the key messages from Adolescent Nutrition 3 – Strategies and intervention for healthy adolescent
growth, nutrition and development - Lancet series
Key messages:
* Double burden – despite micronutrient deficiencies/food insecurities, overweight and
obesity rapidly increasing
* A lack of targets/standardised data to inform action, and nutritional action (but this life
stage sets foundation for a healthy start to life for the next generation)
* Multifaceted/multisectoral action great promise, to date only focused on single
micronutrient
* Greater government fiscal and policy action to restrict availability of highly processed
foods and enhance healthy/diverse adolescent diets – urgency needed
* Greater retention in education means schools can provide healthy food environments,
skills/knowledge and motivation to adopt and sustain healthy diets
* Advocacy in partnership with young people
lancet series 3 recommendations
✓ Build commitment to adolescent nutrition through evidence-based and
accountable systems *
✓ Enhance policy and programmatic actions that favour healthy adolescent
nutrition **
✓ Place adolescent nutrition advocacy within a broader ecological
context…“partner with young people in advocacy”
why is research and development in adolescence a missed opportunity?
- Inadequate focus, funding and intervention on adolescent health
- Interventions and investments are needed in adolescence
- Greater visibility and understanding of adolescent food choices and their consequences
- Benefits later adult life and optimal growth of next generation
- Opportunity to interrupt intergenerational cycles of malnutrition
energy requirements in adolescence and impact of deficits
- Adolescent requirements can be as high as that for adulthood
- Provided by carbohydrate, protein and fat
- Deficits may result in poor growth and failure to reach height potential (stunting)
carbohydrate requirements in adolescence and impact of deficits
- Primary energy source for optimal brain function and to preserve protein for other functions
- AMDR: 45-65% total energy
- Preferred source: wholegrain products which contain more fibre and micronutrient
fat requirements in adolescence and impact of deficits
- AMDR: 20-35% total energy, with <10% from saturated fat
- Replacement of saturated fat with unsaturated fats is beneficial, however some saturated fats in some food
sources may be protective for chronic disease (e.g., in dairy products). - Consume omega-3 fatty acids regularly (oily fish, seafood, soy, seeds, nuts, dark green veg, canola, eggs)
importance of fibre during adolescence
- Associated with healthier bowel, improved blood cholesterol, blood glucose, blood pressure, lower weight
- Concern with the rise of processed foods
key micronutrients for adolescence and why
Zinc
* High to meet requirement of growth and sexual development
Folate
* B-group vitamins required to assist in releasing energy for use for rapid growth
* Particularly important for pregnant adolescents
Calcium
* More than 50% of bone mass is developed during adolescence!
* Adequate calcium essential to achieving peak bone mass and reduce risk of osteoporosis
Vitamin D
* Sun exposure to be balanced with risk of skin cancer
* Where there is minimal outdoor time, food sources of Vitamin D (fortified milk, margarine and
eggs) or supplement should be considered if serum levels are low
Iron
* Increases to meet demands of rapid growth (increase blood volume & muscle mass) and for females the beginning of menstruation
importance of iron in adolescence and deficiency impacts
- Increases to meet demands of rapid growth (increase blood volume & muscle mass) and for females the beginning of menstruation
- Inadequate iron leads to
→ compromised growth
→ decreased cognitive function
→ physical performance and fatigue
→ depressed immune function - Little reduction over three decades in iron deficiency anemia
- Third most important cause of lost disability-adjusted life-years in adolescents
- Teenage pregnancy (link back to week 3 lecture and see adolescence nutrition and health)
are australian adolescence meeting recommended dietary intake
no under-eating fruit, veg, grain foods, meat and alternatives and, dairy and alternatives. overeating discretionary foods
concern between weekdays and weekends
- Increased choice of discretionary food
- Added sugar intake significantly higher on weekends
- Fibre intake lower
adolescent nutrition and health concerns
- Added free sugars
- Energy drinks
- Alcohol
- Overweight and obesity
- Academic performance
- Vegetarianism
- Eating disorders
- Adolescent pregnancy
- Physical activity
what are contributors to added sugar intake
soft drinks i.e., sugar sweetened beverages (SSBs) (28%)
cakes and muffins (7.7%)
sugar, honey & syrups (6.3%)
fruit and vegetable juices (5.9%)
chocolate and chocolate-based confectionary (5.7%)
explain the nutritional concern around energy drinks
- Sugar + caffeine (caffeine in 1-2.5 cups coffee)
- Stimulant, enhancing endurance performance and concentration at moderate levels
- Students report to consume these for sports performance and an energy boost
Caffeine toxicity
- palpitations, agitation, tremor, GIT symptoms and cardiac and neurological effects
Low-moderate intake
- disruptive and hyperactive behavior, sleep disturbance
- potentially long-term preference for food/drink associated with caffeine (i.e., sugar with caffeine in the
case of energy drinks)
* Practice of consuming energy drinks with alcohol may mask feeling of being drunk
recommended alcohol consumption for adolescence
0
what are the percentiles on a growth chart indicating overweight and obese
overweight - 85th to <97th
obese >97th (including 97th)
explain ‘triple burden’ of malnutrition of adolescents
Adolescents vulnerable to:
* Undernutrition
* Micronutrient deficiencies
* Overnutrition
- Both adolescent undernutrition and obesity coexist across low- and middle-income countries
- With overweight/obesity tending to be most
prevalent in high-income countries
what are the percentiles on a growth chart indicating underweight
<5th
what is the importance of glucose and academic performance
Glucose:
* Preferred energy source for the brain
Low glucose:
- Agitation and irritability (hormones, cortisol and adrenalin)
- Lack of concentration
- Due to:
1. lack of food, or
2. foods delivering high glucose load (where insulin overcompensates)
- Regular consumption of any core foods (except meat and alternatives) over the day will provide steady
supply of glucose
why vegetarian eating patterns are adopted for adolescents and recommendations for vegetarianism in adolescents
Vegetarian eaten pattern may be adopted during adolescence, due to:
* Environmental impact
* Animal welfare
* Health reasons
Well-planned vegetarian diet can meet growth and development requirements:
* Special consideration: protein, iron, zinc, calcium, Vit D, omega-3 fatty acids, Vit B12
* For adequate intake of all essential amino acids, a variety of plant-based protein
foods are required, including grains, legumes, vegetables, nuts and seeds
* For adequate intake of iron, include Vitamin C containing foods with iron-containing
plant foods
* For vegans, consideration as to how Vit B12 will be obtained (e.g., fortified foods
such as tofu)
* Has been associated with reduced risk of obesity, hypertension, cardiovascular
disease and cancer
concerns around adolescent pregnancy in nutrition
adolescence is a time of rapid growth -> higher energy requirement
public health concerns with adolescents nutrients and physical activity
Nutrients
* Girls
→ 40% have inadequate iron intakes
→ 90% have inadequate calcium intakes
* Both girls and boys have a low prevalence of inadequate dietary folate equivalents and iodine intakes
Physical activity
* Less than 1 in 5 (16%) of children complete the recommended amount of physical activity
