Nutrition from Infancy Through Adolescence

Infancy

Infant Growth and Physiological  Development

• Infant birth weight doubles in the first 4-6 months then triples within the first year
• Rapid growth requires a lot of sleep and nutrients
• After first year it takes 5 more years to double weight
• Increase in length in first year by 50% and height is complete by early 20’s
• Head size is in proportion to total height but shrinks from 1/4 to 1/8
• Human body needs a lot more food to support growth and development than it does to merely maintain its size once growth stops
• Nutrient poor diets do not support growth
• Developing countries
  • Under-nutrition observed
  • When breast feeding ceases children are feed a high carbohydrate, low protein diet
  • Diets are also low in energy, protein, calcium, iron and zinc
  • Causing slower growth and shorter stature
• Infant development follows a pattern
  • Body water falls from 70% at birth to 60% at 1 year
  • Body nitrogen content increases from 2% at birth to 3% at 1 year – indicating new lean tissue synthesis

Effects of Under-nutrition on Growth

• Long term effects of nutritional problems in infancy and childhood depend upon severity, timing, and duration of the nutritional insult to cell processes
• Best indicator of a child’s nutritional status is growth (HEIGHT and WEIGHT)

Assessment of Infant Growth and Development

• CDC released growth charts
• Look at growth chart in the book
• Growth charts based on percentile rank and/or BMI for girls and boys from birth to 36 months
• Options for charts: weight-for-height, length-for-age, weight-for-length, and head circumference
• Preferred growth chart for children and adolescence (2-20) is BMI
• BMI for adults is fixed but not true for children
• BMI is age and gender specific
• Takes 1-3 years for an infant to establish his/her own genetic percentile

Brain growth

• Rapid growth until 18 months

Infant Needs

• Infant formula at first
• Compare composition of Human milk, Cow’s milk, and infant formula
  • Human milk provides most energy (kcal/L), carbohydrates (g/L) and fat (g/L)
  • Cow’s milk provides most protein (g/L) and minerals (g/L)
    • Protein sources: casein and whey proteins
    • BUT infants usually cannot tolerate cow’s milk
  • Infant formulas provide similar amounts of all nutrients
• Solid foods introduced at six months but formula still primary food source until year one
• Energy
  • 0-3 months [89 X weight (kg)] + 75
  • 4-6 months [89 X weight (kg)] + 44
  • 7-12 months (89 X weight (kg)] -78
  • kcals in first 6 months is 2-4 times more energy need than adults
  • High energy need result from high growth and metabolism
• Carbohydrates
  • From milk and solid foods (after month 6)
  • 0-6 months 60g/day
  • 7-12 months 95g/day
• Proteins
  • 1.5g/kg body weight/day
  • Half of total protein intake should come from essential amino acids (remember there are 10 essential amino acids for infants!)
    
  • Human or infant formula are sources
  • Too high of protein intake could stress kidneys
• Fat
  • 30g of fat per day
  • AI = 30 – 31 grams
  • Essential fatty acids should make up 15% of total (4-5g/day)
  • Human infant and infant formula are sources
  • Two fatty acids found to be absolutely necessary: Arachidonic acid (AA) and Docosahexaenoic acid (DHA)
  • AA and DHA used in brain and eye development
  • AA and DHA found in human milk and currently found in infant formula
• Vitamins
  • Vitamin K injection given at birth
  • Infant formula fortified with vitamins
  • Vitamins in human milk dependent on mother’s diet
• Minerals
  • Iron stores are depleted quickly in infants
  • Give iron fortified formula
  • Zinc and iodide may be lacking
  • Fortification of zinc and iodide necessary for growth
  • Fluoride necessary for tooth development
• Water
  • Infant needs 2 ounces per pound per day
  • 150 ml/kg
  • Too little water and too much water may lead to health problems
  • Conditions leading to water loss calls for supplemental water
  • BUT excess fluid can be harmful, especially to the brain
  • Limit supplemental fluids to 4 ounces per day
• Nutrient Labels
  • Serving size
    • Based on average eaten at one time by a child under two years of age
  • Total fat
    • Does not list calories from fat, saturated fat, or cholesterol
    • Infants and toddlers need fat for growth and development
    • Parents should not restrict fat intake
  • Daily Values
    • For infants and children under four years old
    • Lists percentage of protein, vitamins, and minerals

Introduction of Solid Foods

• Recommendations for timing the introduction of solid foods:
  • Nutritional needs
    • Iron and vitamin D may be low in breast milk and unfortified formulas
  • Physiological capabilities
    • Starch digestion and protein metabolism
  • Physical ability
    • Disappearance of extrusion reflex (thrusting tongue forward)
    • Head and neck control
    • Ability to sit up
  • Allergy prevention
    • Introduction of certain proteins too early may predispose a child to future allergies
• Solids foods
  • First solid foods should be iron-fortified cereals
  • Introduce after breastfeeding or formula feeding – edge has been taken off hunger
  • Rice cereal best to begin with – least likely to cause allergies
  • Pediatricians may recommend lean ground (strained) meats for iron source
  • After a week of introducing a new food without ill effects another food item can be introduced
  • Recommended to introduce vegetables before fruits (may cause preference for sweet taste)
  • Recommended not to introduce mixed foods until each component of mixed food has been given separately – if not a food allergy may develop
• Foods not to feed an infant
  • Honey – may contain spore of Clostridium botulinum
  • Very salty or very sweet foods
  • Excessive infant formula or human milk
  • Foods that may cause choking
  • Cow’s milk – contains high protein and mineral content an infant cant process well; after two years a child is able to process 1% and non-fat milk
  • Feeding excessive amounts of pear or apple juice – fructose and sorbitol may cause diarrhea

Health Problems Related to Infant Nutrition

• Colic – sharp abdominal pain that generally occurs in otherwise healthy infants
• Diarrhea – caused by bacterial and viral infections as well as dietary intolerances
• Milk Allergy – cow milk allergy due to proteins
• Iron deficiency anemia – anemia as a result of low iron in diet
• Gastroesophageal reflux – esophageal sphincter may not fully close
• Early childhood caries – tooth decay resulting from formula or juice bathing teeth as child sleeps with a bottle in his/her mouth

Preschool Children

Growth (3-5 yrs of age) and Needs

• Average annual weight gain is 4.5 to 6.6 lbs
• Average annual height gain is 3 to 4 inches
• Tapering growth rate may lead to reduced appetite and changed eating behavior (“picky eaters”)
• Energy requirements (1-3 yrs old): [89 X weight (kg)] -80
• Carbohydrates: 130g/day
• Proteins: 1.1g/kg weight/day; 13-19g/day 1-3 years
• Fat : no specific needs set but at least 5g/day of essential fatty acids needed
• Vitamins: No supplements necessary; emphasize good foods
• Minerals:
  • No supplements necessary; emphasize good foods
  • 500-800mg/day of Calcium  needed
  • 10mg/day of Iron needed
• USDA created a food guide pyramid for ages 2-6
  • 6 servings of grains
  • 3 servings of vegetables
  • 2 servings of fruits
  • 2 servings of milk
  • 2 servings of meat
  • “Eat less” fats and sweets

Health Problems in Preschool Children

• Iron Deficiency Anemia
• Constipation
  • Fiber recommendation: 19g/day for children 1-3 years
  • Water intake recommendation: 5 cups per day for toddlers
• Dental caries

School Aged Children to Preteens

Growth (6-13) and Needs

• Food guide pyramid remains the same except serving size increases
• Energy requirements: (Harris Benedict!)
  • Boys 3-8:
    • 88.5 – (61.9 X Age [in years]) + (PA X (26.7 X Weight [kg] + 903 X Height [meters]) + 20
    • PA (physical activity): 1.00 (sedentary). 1.16 (low active), 1.26 (active) and 1.42 (very active)
  • Girls 3-8:
    • 135.3 – (30.8 X Age [in years]) + (PA X (10.0 X Weight [kg]] = 934 X Height [meters]) + 20
    • PA (physical activity): 1.00 (sedentary). 1.16 (low active), 1.31 (active) and 1.56 (very active)
  • Note: + 20 in formula for both boys and girls is replaced with + 25 in older children
• Carbohydrates: 130g/day
• Proteins: 0.95g/kg weight/day; 34-52g/day for older children
• Fats: none specified
• Vitamins and minerals:
  • Recommended amounts just under those of adults
  • Possible introduction of vitamin and mineral supplements

Health Problems

• Type 2 Diabetes
• Obesity

Teenagers

Growth (14-18) and Needs

• Food guide pyramid for this group nearly reflects those for adults
• Energy requirements: reflect adult caloric intake
• Carbohydrates: 130g/day
• Proteins: 0.85g/kg weight/day; or 52 g/day males and 46 g/day females
• Fats: none specified
• Vitamins and minerals:
  • Recommended amounts equal those of adults
  • Possible introduction of vitamin and mineral supplements

Health Problems

• Anorexia and Bulimia
• Iron Deficiency
• Lack of calcium
• Increased sodium intake