lecture 7: adolescence

Question 1

what are the key messages from adolescent Nutrition 1 - Nutrition on adolescence growth and development - Lancet series

Answer 1

• 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

Question 2

describe adolescent physiological development in terms of height and weight

Answer 2

• 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

Question 3

describe adolescent physiological development in terms of sexual maturation

Answer 3

• 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

Question 4

describe adolescent physiological development in terms of body composition

Answer 4

• 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

Question 5

describe adolescent physiological development in terms of body skeletal growth

Answer 5

• 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

Question 6

describe early adolescence development

Answer 6

• 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

Question 7

describe middle adolescence development

Answer 7

• Increased
  emotional
  independence
  from family
• Increase in health
  risk behaviors
• More comfortable
  with developing
  body
• Some financial
  independence

Question 8

describe late adolescence development

Answer 8

• 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

Question 9

what are the key messages from Adolescent Nutrition 2 – Food choice in transition
(adolescent autonomy, agency, and the food environment) - lancet series

Answer 9

• 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.

Question 10

individual factors influencing adolescent nutrition and diet

Answer 10

• 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

Question 11

social factors influencing adolescent nutrition and diet

Answer 11

• 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

Question 12

environmental factors influencing adolescent nutrition and diet

Answer 12

• 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…)

Question 13

what are the key messages from Adolescent Nutrition 3 – Strategies and intervention for healthy adolescent
growth, nutrition and development - Lancet series

Answer 13

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

Question 14

lancet series 3 recommendations

Answer 14

✓ 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”

Question 15

why is research and development in adolescence a missed opportunity?

Answer 15

• 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

Question 16

energy requirements in adolescence and impact of deficits

Answer 16

• 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)

Question 17

carbohydrate requirements in adolescence and impact of deficits

Answer 17

• 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

Question 18

fat requirements in adolescence and impact of deficits

Answer 18

• 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)

Question 19

importance of fibre during adolescence

Answer 19

• Associated with healthier bowel, improved blood cholesterol, blood glucose, blood pressure, lower weight
• Concern with the rise of processed foods

Question 20

key micronutrients for adolescence and why

Answer 20

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

Question 21

importance of iron in adolescence and deficiency impacts

Answer 21

• 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)

Question 22

are australian adolescence meeting recommended dietary intake

Answer 22

no under-eating fruit, veg, grain foods, meat and alternatives and, dairy and alternatives. overeating discretionary foods

Question 23

concern between weekdays and weekends

Answer 23

• Increased choice of discretionary food
• Added sugar intake significantly higher on weekends
• Fibre intake lower

Question 24

adolescent nutrition and health concerns

Answer 24

• Added free sugars
• Energy drinks
• Alcohol
• Overweight and obesity
• Academic performance
• Vegetarianism
• Eating disorders
• Adolescent pregnancy
• Physical activity

Question 25

what are contributors to added sugar intake

Answer 25

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%)

Question 26

explain the nutritional concern around energy drinks

Answer 26

• 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

Question 27

recommended alcohol consumption for adolescence

Answer 27

0

Question 28

what are the percentiles on a growth chart indicating overweight and obese

Answer 28

overweight - 85th to <97th
obese >97th (including 97th)

Question 29

explain ‘triple burden’ of malnutrition of adolescents

Answer 29

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

Question 30

what are the percentiles on a growth chart indicating underweight

Answer 30

<5th

Question 31

what is the importance of glucose and academic performance

Answer 31

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

Question 32

why vegetarian eating patterns are adopted for adolescents and recommendations for vegetarianism in adolescents

Answer 32

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

Question 33

concerns around adolescent pregnancy in nutrition

Answer 33

adolescence is a time of rapid growth -> higher energy requirement

Question 34

public health concerns with adolescents nutrients and physical activity

Answer 34

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