Exam 4- Childhood/Adolescence Flashcards
Toddlers (1-3 years)
Growth rate slows down
- appetite/food intake compared to infancy
Transition to independent feeding
- can still choke
-small stomach= frequent snacks
Strong likes & dislikes; distinct food preference
- food jags (eat same food all the time)
- neophobia (fear of new foods)
Wide variation in physical activity (PA)
Early Childhood (4-8 years)
Period of lowest growth rate
Transition from feeding skills to eating habit
Knowledge/belief of food influenced by
- parents, siblings, teachers
- media
Wide variation in PA (screen time)
Growth:
toddlers thru adolescence
Influence of genetic potential ↑
Gender difference becomes apparent
- boys slightly taller and heavier than girls
Adolescent growth spurt
- girls begin and end earlier than boys
- peak height velocity (PHV) girls-12, boys-14
- total height gain: boys>girls
Body composition:
- pre-puberty % body fat: boys-15%, girls-19%
- during puberty: girls gain proportionately more fat due to estrogen & progestrone
- after puberty % body fat: boys-15% girls-23%
Growth (BMI)
toddlers thru adolescence
Normal BMI change with age
- 50th %tile values for boys:
16. 5 at age 2, 15.5 at age 6, ~20 at age 15
BMI curve: U-shape
- decreased at age 2-5, lowest (nadir) at 4-8, increases (rebound) afterwards, continue to increase thru adolescence
BMI nadir and rebound
- girls earlier than boys - heavy children earlier than light children - earlier rebound linked to increased risk of obesity
Overweight/obesity definition
- based on percentiles, not absolute BMI (kg/m2) - relationship to adult definitions At age 20 Boys Girls Adult 50th percentile BMI 23 21.8 85th percentile BMI (OW) 27 26.5 25 95th percentile BMI (OB) 30.5 31.8 30
Categories of BMI status
< 5th percentile: underweight
5-84th percentile: healthy weight
85-94th percentile: overweight
≥95th percentile: obesity
DRI: Energy and Macronutrients
toddlers (1-3)
Same EER equation as infants’ but +20 kcal for growth Fat: 30-40% CHO: 45-65% Protein: 5-20% Protein RDA: 1.05 g/kg BW
DRI: Energy and Macronutrients Early Childhood (4-8 years)
girls:
EER = 135.3 – 30.8 x age + PA x
[(10.0 x wt) + (934 x ht) + 20
boys:
EER = 88.5 – 61.9 x age + PA x
[(26.7 x wt) + (903 x ht) + 20
age 4-18 yr
Fat: 25-35%
CHO: 45-65%
Protein: 10-30%
Protein RDA (4-8): 0.95 g/kg BWDRI: Micronutrients (RDA/AI)
Calcium
toddlers: 700
4-30: 1000
DRI: Micronutrients (RDA/AI)
Iron
infants: 11
toddlers: 7
early childhood: 10
adults: M:8 and W: 18
Nutrients of concern
Vitamin A iron calcium zinc Vitamin D (40% of toddlers take supplement but not really recommended)
Actual intake from NHANES Survey
% of children drinking milk decreased from 85% (1976-80) to 77% (2001-06)
- intake of milk decreased while fruit juice increased
Juice consumption increased from 30% (1976-80) to >50% (2001-06)
- AAP and DGA recommends 4-6 oz/day for 1 y.o. (actual is 10-12 oz/day)
Soft drink increased from 7 oz/day (1976-80) to ~8 oz/day (2001-06)
Eating Patterns of Children
Meals at home decrease, Meals away from home increase
- meals with families at home have higher diet quality - calorie intake away from home increase from 23% in 1977 to 34% in 2006 - fast food was the largest contributor, 13% of calories
Meal patterns and meal frequency
- of children skip breakfast (NHANES 1999-2006) - snacking from 4x per day (1977-78) to 5x per day (2006-10) - of calories come from snacks; largest increases in salty snacks & candy
Portion sizes
- when larger entrée portions are offered, children age 3-5 y consume more of the entrees and less of “other” (e.g., F & V)
Beverage consumption
Development of eating habits food preference lecture
Growth and Feeding/Eating Characteristics: Adolescence
Adolescence (9-13 & 14-18)
Growth spurt; sexual maturation
- appetite increases during growth spurt
↑ Meals/snacks away from home
- skipping breakfast
-decreased milk, increased sweetened beverages
Eating habit strongly influenced by peers
-maybe sudden/dramatic (e.g. vegetarian)
Wide variation in PA (screen time & sports)
Puberty
process of physically developing from child to adult, physical growth and sexual maturation
F: 10.5 -14
M:12-16.5
Timing of growth spurt correlate closely to stages of sexual maturation
Progression of puberty: sequence of pubertal events is consistent, but age of onset, magnitude and duration vary greatly among individuals - “early”, “average” and “late” maturers
Tanner stages
A scale to assess the characteristics & degree of sexual maturation of adolescents, regardless of chronological age.
Girls: based on breast development and pubic hair
Boys: based on genital and pubic hair development
- Separate stage established for each of the 2 characteristics
Tanner stage categories
Stage ranges from 1 to 5 Girls: B1 to B5 and PH1 to PH5 Boys: G1 to G5 and PH1 to PH5 - Stage 1: pre-pubertal - Stage 2: onset: earliest visible signs - Stage 5: mature, adult development
Tanner stages - girls - common characteristics
Earliest sign of puberty
- breast budding, usually obvious; onset of B2
- average age 10½ y.o. (age range 9-13 y.o)
Breast development- B2 to B5 takes ~4 years
Peak Height Velocity
- occurs before menarche
- usually during stages 2-3
Menarche
- average age 12½ y.o.
- usually during stages 3-4
Other signs of puberty e.g., acne
Tanner stages - boys - common characteristics
Earliest sign of puberty - testes enlarges, usually subtle; onset of G2 - average age: no data Genital development - G2 to G5 about 3 y PHV - usually during stages 3-4 Other signs of puberty: voice deepening, mustache, etc
DRI: Energy and Macronutrients- adolescence
Energy: same as 3-8 but +25 kcal for growth Protein RDA: 9-13: 0.95 g/kg 14-18: 0.85 g/kg AMDR: Fat: 25-35% CHO: 45-65% Pro: 10-30%
DRI: Micronutrients (RDA/AI)- calcium
9-18: B:1300 G:1300
18+: 1000
DRI: Micronutrients (RDA/AI)- iron
9-13: 8
14-18: B: 11, G:15
Adults: B:8, G: 18
Energy & nutrient requirement influenced by growth rate and physical activity level
- chronological age is a poor indicator of requirement
2 girls of the same age have very different requirement if one is pre-pubertal and the other is during puberty - adolescence: high risk of developing obesity and eating disorder
Adolescence - a critical stage of bone Ca accretion
- ½ of adult boss mass accrued, peak bone mass reached 20-25 years of age
- Ca absorption rate highest
- average Ca intake: 800-1200 mg in adolescent boys, 500-800 mg in girls
Adolescence and Fe
- high requirement during growth spurt (Increased LBM and blood volume)
- highest requirement: PHV in boys and after menarche in girls
- iron intake: 32% adolescent boys and 83% adolescent girls are below RDA
- Fe-deficiency anemia higher in adolescents than pre-pubertal children
Nutrients of concern- adolescence
Vitamin A, D, E Folate Iron Zinc Magnesium Calcium overnutrition: too much sodium and sat fat, 1 in 5 overweight/obese
Tips to Promote Healthy Eating in Adolescence
Parents can:
-have healthy snacks readily available
◦Help them learn more about nutrition in a peer-oriented fashion
-take their suggestions when preparing foods at home
◦Try to have an least 1 family meal at home per day
-will adopt if they know how it will affect sports, academic performance and body look
Genetic Predisposition for food preferences
Unlearned ( innate ) Taste Preferences
Newborns-children food preference
Newborns have a preference for sweet taste
and an aversion for bitter tastes
-preference for salty foods at 4 mo
-energy dense foods
-accept familiar foods and reject new flavors (neophobia)
Impact of Innate Taste Preferences
Advantageous from an evolutionary standpoint
- energy-dense food ↑ chance for survival
- potential toxins are often bitter/sour and unfamiliar
Potential obstacle for promoting healthy eating in the current obesogenic environment
- unfamiliar sweet/salty/energy-dense foods readily accepted; prone to over-consumption when large portions offered
Aversion to bitter/sour and neophobia
- intro of certain foods (e.g., vegetables) difficult; acceptance/preference for novel flavors need to be learned
Flavor Learning Early in Life: Acceptance of new foods promoted by
Prenatal exposure to flavors in amniotic fluid
- taste and smell functional in fetus
- fetus regularly swallows amniotic fluid
Postnatal exposure to flavors in breast milk
- many flavors of maternal diet appear in breast milk, e.g. garlic
- breast milk provides a “flavor bridge” that familiarize infants with a variety of flavors
Breastfed infants more likely to
- accept new food at first exposure
- prefer & consume more new food when introduced repeatedly
Carrot Flavor Study: hypothesis
prenatal and early postnatal exposure affects food acceptance
Carrot Flavor Study: Study design
Treatment: exposure to carrot flavor
- carrot juice 300 ml/day given to mothers during pregnancy and/or lactation
- pregnancy: during the last 3 wk of the 3rd
- lactation: during the first 2 mo of lactation
Control: water
3 groups total: WC, CW, WW
Outcome measure: infants acceptance of carrot flavored cereal at weaning (5 mo)
Results- Carrot Flavor Study
- significantly less negative faces in WC and CW groups vs WW
- mothers perception: increased in WC and CW
- intake greatest in CW, lowest in WW
- Food Acceptance Can be Changed by Repeated Exposure
Acceptance of foods with less intrinsic appeal to children (e.g., veges ) are
- affected by their experience to those foods
- enhanced by repeated exposure (10-16 times) in a non-coercive setting
- Simply offering new foods are not enough, having children “taste” the food is necessary
Vegetable Intervention Study: hypothesis
repeated exposure changes acceptance
Vegetable Intervention Study: treatment
Treatment: repeated exposure to a disliked vegetable - offer a disliked veg (“target veg”) to 2-6 y.o. children daily for 14 days
- target veg chosen from: carrot, cucumber, tomato, celery, green pepper, red pepper
A 2nd “treatment” group: the “information” group
- nutrition advice & nutritional education leaflet to parents
Control: receives nothing
Vegetable Intervention Study: outcome measure
taste test on target vegetable pre and post intervention
Vegetable Intervention Study: results
p<0.05 and **p<0.001 comparing pre- and post-
vege intake: exposure=significant increase in target vege consumed, info and control didn’t change much
Repeated Exposure Works -Personal Experiences
Brown rice Degree of sweetness and saltiness Works in adults too! -Immigrants -Tomato (a NS431 student!)
environmental impact to food preference
- advertising
- foods available in the home/school
