Infancy, childhood and adolescence

Satisfactory growth

Only during the 1st half of infancy

• Computed from rates of protein and fat deposition (longitudinal studies)
• ~175 kcal/d for 0 – 3 months -> 20 kcal/d for 13 – 35 months

Lack of gender differences

Limited range of physical activity?

• Sensitive indicator of energy status
• Will detect growth faltering earlier than growth charts

Acute episodes of dietary intake

Affected by chronic factors

Energy expenditure/kg is 2x greater in infants than adults

• Energy content of newly synthesized tissue
• Estimated from cost of protein and fat deposition

Primarily brain, liver, heart and kidney

• Increase during the transition to extrauterine life
• After birth, O2 consumption of these vital organis increases in proportion to increase in organ weight
• Brain contribution exceptionally high (70%) in newborn, and in 1st years of life (60-65%)

• Decreases from 35% at 1 month to 3% at 12 months
• Remains low until pubertal growth spurt where it increases to 40%

• Increase in non-shivering thermogenesis --> increase in metabolic rate
• Most important contribution by increase oxidation of A in brown adipose tissue

Increasingly larger component of TEE as child grows

Defined to maintain health, promote optimal growth and maturation, support a desirable level of PA

Increase in stature and weight, changes in body composition and organ systems

Developmental changes in reproductive organs, development of secondary gender characteristics, changes in cardiorespiratory and muscular systems (increase strength and endurance)

Fat-free mass

Marked gender differences in intensity and duration of growth spurt in FFM

~60g CHO=37% of total food energy (amount in milk is assumed to be optimal)

~0.78L/day

median CHO intake from weaning foods =50g/day

0.6L/day

• CHO from human milk=44g
• CHO from foods = 50g
• Total needed=94g

• Nutrient dilution effect by nonmilk extrinsic sugars
• High [sugar] intake (>24% of energy)--> most micronutrient intakes between 6-20% below average

• Constant of increases modestly
• In the range reported for adults
• EAR and RDA for CHO based n information used for adults
• Same for both genders

14g/1000kcal x median  energy intake

• Individuals consuming less than median energy intake need less fiber
• 1 year olds not meeting this energy consumption level will not require as much fiber and their intake should be scaled back accordingly

• No functional criteria for fiber status reflecting response to dietary intake
• Human milk is the optimal source of nourishment and it contains no fiber

Formula is higher in protein than milk

Despite lower protein intakes, breast-fed intants have better imune function and behavioural development

• Stays about the same 1.52g/kg/day
• May be a bit of an overestimate since growth slows down towards the end

• Factorial method
• Relationship between protein intake and nitrogen balance were utilized to estimate protein requirements by the factorial method

• Estimates of maintenance requirement
• Measurement of rates of protein deposition
• Estimates of the efficiency of protein utilization for growth

1.72 the efficiency of protein utilization for growth

• 0-6 months: 31g/day
• 7-12 months: 30g/day

Yes

Based on average intake of fat from human milk and complementary foods

~5.7g/day

• Amount of n-6 PUFAs in human milk
• 4.4g/day

1.2g/day

• Milk: 390kcal/day
• Foods:281kcal/ay

6%

Provide DHA which is important for the developing of the brain and retina

• 0.5g/day
• 1% of energy intake

• 0.68L/day
• Because 0.78L of milk is consumed and milk s 87% water
• Round to 0.7L/day

Need 0.8L/day- comes from milk (0.52L) and complementary foods (0.32)

• Normal hydration status can be achieved with a wide range of total water intakes
• AI for total water is based on median total water intake of children and adolescents

• 0-6 months: based on mean intake of milk-fed infants
• 7-12 months: based on human milk and complementary foods

Maturation of kidneys is similar im normal children by 12 months of age

• Extrapolated down from the adult AI of 1.5g/day
• Using the average of median energy intake levels of the age groups for adults and for children

• Based on average amount of potassium in human milk
• Mean intake: 0.39g/day (round to 0.4g/day)

0.7g

• Increased blood pressure, bone demineralization, kidney stones
• Result from inadequate intake over an extended period of time, including childhood

• Extrapolated from adult intakes
• Adjusted based on energy intake

• Adjusted based on energy intake
• Concern that adjustment based on weight might lead to a relatively low and potentially inadequate intake of potassium
• A greater intake of dietary K would be appropriate to mitigate adverse effects of Na

• Set at a level equivalent on a molar basis to that of Na
• Almost all dietary Cl comes with the Na added during processing or consumption of foods

• Mean intake data from infants fed human milk exclusively
• Ad the [vitamin and mineral] of milk produced by well-nourished mothers

Extrapolated from estimates of nutrient intake from human milk PLUS nutrients provided by usual intakes of complementary weaning foods

• Maintenance needs for vitamins and minerals expressed with respect to body weight (kgbody weight)^0.75
• Set to power of 0.75 to adjust for mertabolic differences related to body weight

A 10% CV for the requirement is assumed unless data are available to support another value

Set on the basis of the highest median intake for each age group

Most likely due to the method used to set the AI for older infants and the increased portion of the diet containing vitamin K-rich fruits and vegetables as the diet becomes more diversified

Vitamin K is poorly transported across the placenta

• Increased risk of bleeding during the first weeks of life
• Hemorrhagic disease of the newborn

• Between 3-8 weeks
• Usually associated with breast-feeding

• Can be effectively prevented by administration of vitamin K
• Infants born in North America routinely receive 0.5-1mg of phylloquinone i.m.
• OR 2mg orally within 6 h of birth (less effective)

Reflects a calculated mean vitamin K intake of infants principally fed human milk and provided vitamin K prophylaxis

By extrapolating up from young infants

• Extremely rare in the general population
• Limited to individuals with malabsorption syndromes or those treated with drugs known to interfere with vitamin K metabolism

• 100mg/day
• Using an estimate of 20% net Ca retention
• RDA is set for Ca at 700mg/day

• Ca accretion=200mg/day
• Require a Ca intake of 800 to 900 mg
• RDA for calcium is 1000mg/day

• The factorial approach
• Ca retention to meet peak bone mineral accretion
• Clinical trials: bone mineral content measured in response to variable Ca intake

1300mg/day: slightly above the 75th percentile of Ca intake

• 1300mg/day
• Slightly below the 90th percentile of Ca intake

• Current levels of Ca intake among adolescents not adequate to support development of optimal bone mass
• Supplements may be necessary

• Reflects mean Fe intake of infants principally fed human milk
• Assumed that the Fe provided by human milk si adequate to meet the Fe needs of infants exclusively fed human milk from 0-6 months

• Obligatory: fecal, urinary, and dermal losses (basal losses)
• Increased hemoglobin mass (increased blood volume and increase in [hemoglobin])
• Increase in tissue (non-storage) Fe
• Increase in storage Fe

Use 10% bioavailability because they mostly eat cereals and fruits and not many eat meat or meat mixutres

Use 18% bioavailability

• Basal Fe losses
• Increase in hemoglobin mass
• Increase in tissue (non-storage Fe)
• Menstrual Fe losses in adolescent girls
• No provision for the development of Fe stores after early childhood

65ug/day

• 0.05mg/kg/day
• Recommended for all ages >6 months
• Protection against dental carries

• Caused by Fe ingestion during the pre-eruptive development of the teeth
• After enamel has completed its pre-eruptive maturation--> no longer susceptible (by 8 years of age)
• Milder forms of fluorosis: white opaque patches, often most apparent on the edges of teeth (snow capping)
• Preeruptive maturation of the crowns of the anterior permanent teeth