Lecture 8 Nutrition

• Early nutrition


  Affects later development
• Early feeding


  Influences eating habits throughout life
• Infant diet


  • Breast milk
  • Formula
• Infant feeding


  1. Exclusively breast milk or formula (0-6 months)

  2. Breast milk/formula and introduction of solid food (6-12 months)
• Infancy


  • Fast growth
  • High metabolic rate
• Infant birthweight


  Doubles by about 5 months, triples by one year
• Infant energy needs


  100-110 kcal/kg body weight/day
• Infant macronutrient needs


  • Fat (35-50%)
  • Protein (5-10%)
  • Carbohydrates (40-50%)
• Infant micronutrient needs


  • Vitamin D (increase)
  • Calcium (increase)
  • Vitamin A (increase)
  • Iodine (increase)
  • Folate (increase)
  • Vitamin E (increase)
  • Vitamin C (increase)
  • Zinc (increase)
  • Riboflavin (increase)
  • Thiamin (increase)
  • Vitamin B12 (increase)
  • Water (increase)
• Breast milk


  • More easily digested than formula
  • Breastfed infants eat more frequently (every 2-3 hours)
• Breast milk composition


  • Fat (55%)
  • Carbohydrates (39%)
  • Protein (6%)
• Breast milk fat


  • Provides the infant's main source of energy
  • Contains essential fatty acids linoleic (omega-6) and linolenic (omega-3) and their longer-chain derivatives arachidonic fatty acid and docosahexaenoic acid (DHA)
• Breast milk carbohydrates


  • The carbohydrate is lactose, which is easily digested and enhances calcium absorption
  • Also contains oligosaccharides which help protect infant from infection
• Breast milk protein


  • Largely alpha-lactalbumin, which is efficiently digested and absorbed
  • Optimal for growth and development
• Breast milk vitamins and minerals

  • Plentiful for all vitamins except vitamin K and vitamin D (need supplementation)
  • Calcium content optimal
  • Low iron but high bioavailability
  • High bioavailability for zinc
  • Low sodium
  • Optimal fluoride
• Breast milk immunological protection

  • Colostrum contains maternal antibodies to "kick start" immune system
  • Bifidus factors optimal for lactobacillus bifidus growth and healthy gut flora
  • Lactoferrin promotes iron absorption and prevents bacteria from getting iron
  • Lactadherin prevents virus that causes infant diarrhea
  • Growth factors for development and maintenance of GI tract
  • Lipase and other enzymes protect against infection
• Infant formula


  • Tries to mimic breast milk
  • Some infants cannot tolerate standard formulas and need soy-based or other specialized formulas
  • Lacks protective antibodies found in breast milk
• Risks of formula feeding

  • Improper preparation can cause malnutrition, growth failure, infection, diarrhea, dehydration, and malabsorption
  • Unavailability of proper formula in developing countries and poor areas
• American Academy of Pediatrics (AAP) advises against cow's milk in first year
• Transition to cow's milk

  • After 1 year, reduced fat or low-fat milk is an acceptable and recommended accompanying beverage
  • After age 2, transition to fat-free milk can take place
• Introducing first solid foods

  1. Infants are usually developmentally ready between 4-6 months

  2. At 4-6 months, infants need additional iron from iron-fortified cereals, meat, or meat alternatives

  3. Vitamin C enhances iron absorption

  4. Ability to swallow solids develops by 4-6 months

  5. Ability to sit up and handle finger foods develops by 8 months to 1 year

  6. Introduce new foods singly and at intervals to detect allergies
• Foods to omit in first year

  • Sweets (including baby desserts)
  • Canned vegetables (too much sodium)
  • Honey (can cause infant botulism)
  • Foods that present choking hazard
• Foods at 1 year

  • Cow's milk provides major source of nutrients, 2-3 cups per day
  • Other foods in variety and amounts sufficient to round out total energy needs
  • Able to sit at table and eat many of same foods as rest of family
  • Drink liquids from sippy cup, rather than bottle
• Nutrition goals for infants

  • Encourage eating habits to support continued normal weight as child grows
  • Introduce variety of nutritious foods, offered in inviting way
  • Do not force infant to finish bottle or entire jar of food
  • Encourage physical activity
  • Avoid using food as reward or comfort, or denying food as punishment
• Mealtimes


  • Consider developmental and nutritional needs
  • Discourage unacceptable behaviors, remove child from table if needed
  • Let child explore and enjoy food, do not force food
  • Limit sweets strictly
  • Exploring and experimenting are normal behaviors
• After first year, growth rate slows but dramatic changes in the body continue
• Child's energy needs


  • At 1 year, about 800 kcal/day
  • At 6 years, active child needs twice that
  • At 10 years, active child needs about 2000 kcal/day
  • Physically active children require more energy, inactive children can become obese even eating less
• Macronutrient needs in childhood

  • Carbohydrates (45-65% of total energy, complex over simple)
  • Fibre (14 g/1000 kcal, increasing with age)
  • Protein (0.95-1.1 g/kg body weight/day, declining as percentage of body weight)
  • Lipids (25-40% of energy, essential fatty acids similar to adults)
• Micronutrient needs in childhood

  • Iron (important for oxygen transport, neurotransmitter production, focus on iron-rich foods)
  • Vitamin D, calcium (supplements may be needed)
  • Other vitamins and minerals (can be met with balanced diet)
• Children's nutritional needs


  • Children have an innate ability to match their intake with their needs
  • Keeping a nutritious variety of foods available encourages a healthful diet
• Nutrient deficiencies in children often result in behavioral and physical symptoms
• Childhood malnutrition


  • Skipping breakfast leads to short attention span and poor performance
  • Vegan diets potentially low in key nutrients like protein, iron, zinc, vitamin B12, calcium, vitamin D
  • Food allergies related to food protein or other large molecule absorbed into blood
• Keeping a nutritious variety of foods available encourages a healthful diet
• Nutrient deficiencies often result in behavioral and physical symptoms
• Any departure from normal, healthy appearance and behavior may indicate poor nutrition
• Registered dietitian, nutritionist or other qualified health care professional should inspect child's diet
• Take steps to correct inadequacies immediately
• Childhood malnutrition


  • Skipping breakfast
  • Short attention span
  • Poor performance
  • Glucose homeostasis
• Brain in children


  • Relatively same as adults
  • Liver smaller
• Overnight fast


  Results in very low blood glucose in children and "starving" brain