Infancy and early childhood

Monitoring and Interpreting Growth During Infancy and Childhood

First 2 years of life are critical for establishing eating behaviours

When an infant is born, enzyme systems aren’t at full capability 

  • Sticky green ish black poop at first —> loose, seedy yellow colour in breast fed infants (changes as infant develops)

  • Iron in infant formula may affect colour

Primitive sucking feeding reflex —> rotatory chewing action is linked with other developmental stages e.g. development of the musculature of the face and the tongue

Introduction of solids too early: diarrhoea, food allergies, undernutrition —> increased morbidity 

Too late: affects growth, decreased immune protection, increased diarrhoea disease and malnutrition, micronutrient deficiencies and delay in develop of motor skills

Nutrition ‘gap’ emerges (iron, iron stores 4-6 months)

Growth in infancy

  • Birth weight determined by gestation length, maternal pre-pregnancy weight, and weight gain during pregnancy.

  • Newborns lose 5-10% of birth weight initially, regain within 2-3 weeks.

  • By 4-6 months, weight doubles; by 12 months, it triples.

  • Length increases 50% in the first year, doubling by 4 years.

Breastfed vs infant formula

  • Increase resting energy expenditure (REE) in FF —> consistent with higher fat free mass

  • Confounding factors: prematurity, gestational diabetes

  • Difference due to micronutrients/bioactive factors, BM composition between feeds

  • Self regulation vs finishing bottle

Growth Measurements

  • Weight, length, head circumference, mid-arm circumference, and skinfold thickness.

  • WHO charts (up to 5 years) reflect optimal growth (predominantly breastfed).

  • CDC charts (up to 19 years) are references based on US children.

Growth Patterns

  • Between 1-5 years, growth slows down, leading to a fluctuating appetite.

  • Consistent percentile growth is key; crossing 2 percentiles downwards is a concern.

Other monitoring considerations

Timing of serial measurements: frequency important, regular (monthly for 1st 6 months, then 2nd monthly)

Interpretation: 

  • Generally, proceed along percentile line.

  • Concern, if change occurs near the extreme percentiles.

  • Concern, if child crosses 2 percentiles (downwards).

  • For example, if a child’s weight is at the 85th percentile, it means that 85 of 100 children (85%) weigh less and 15 (15%) weigh more.

Key Nutrients for Infants and Their Food Sources

Reflect basal metabolic needs, growth rates, energy expenditure, illness

Energy 

  • Rapid growth leads to high energy needs.

  • Best way to assess adequate nutrient intake using growth charts.

  • FF infants may consume more calories that breast fed babies

Macronutrient 

Protein: required for tissue replacement and growth

  • Higher requirement in infants than older children/adults —> rapid growth period

  • Supplementation (solids) needed after 6 months (BM sufficient for 6 months)

  • Inadequate protein found with excessive dilution of formula, limited food options provided, extreme vegetarian food patterns, multiple food allergies, deprivation of food/formula

Fat: weaning diet made up of lower fat food choices (fruit, vegetables)

  • 30-50% of energy intake

  • Lower intakes (inadequate E intakes)

  • Essential fatty acids (linoleic and α-linolenic) support growth and dermal integrity (provides 3% energy), brain and retina development.

Carbohydrates & fluid: CHO main form lactose and should provide 30-60% of energy.

  • Water provided by BM or formula

Micronutrients:

  • Iron: Stores decline by 4-6 months → Iron-rich foods needed (fortified cereals, meat, poultry, legumes).

  • Zinc: Supports immune function and growth.

  • Vitamin D & Calcium: Critical for bone development.

  • Vitamin C: Helps iron absorption.

Appropriate Weaning Diet (What, When, How to Introduce Foods)

Readiness Signs:

  1. Extrusion reflex disappears, head and neck control, interest in food

  2. Open mouth when given food, closes lips around spoon, clears effectively, moves food to back of mouth & swallows

  3. Oro-facial reaction, change in bowel motion

NHMRC Infant Feeding Guidelines

  • Start at ~6 months (not before 4 months).

  • Iron-rich foods first (fortified cereals, pureed meats, tofu, legumes).

  • Any order is acceptable if iron is prioritised.

  • Continue breastfeeding or formula.

Progression of Textures

  • 4-6 months: Pureed or mashed food.

  • 6-9 months: Soft, minced, or lumpy food (yogurt, custard, fruit, meat, chicken)

  • 9-12 months: Finger foods, finely chopped meats, soft fruits & vegetables.

  • 12+ months: Rotary chewing, more adult-like textures.

Best Practices:

  • Start after milk feeds initially.

  • Introduce one food at a time (every 4-5 days).

  • Avoid added salt, sugar, honey (botulism risk).

  • Introduce potential allergens early (peanut, egg, dairy, wheat, fish, soy).

Food Skills & Milestones in Early Life Stages

Feeding Milestones:

  • 0-4 months: Primitive sucking reflex.

  • 4-6 months: Spoon feeding, biting, digestive system matures

  • 6-9 months: Lip clearing from spoon, biting/chewing, lateral tongue movements.

  • 9-12 months: Self-feeding, finger foods, rotary chewing

  • 12+ months: Uses utensils, jaw stability.

Fussy Eating & Strategies:

  • Normal in toddlers (90% of neophobia is behavioural).

  • Avoid food battles.

  • Keep portions small, repeat exposures (10-15 tries).

  • Encourage family meals, limit sweetened drinks, avoid force-feeding.

Food Allergies:

  • 3-10% of children and up to 10% of adults

  • Common allergens: Cow’s milk, egg, peanuts, tree nuts, wheat, soy, fish, shellfish.

  • Early introduction (4-6 months) reduces risk of allergy development.

  • Consider cross-reactivity (e.g., pollen allergies → fruit allergies).

  • Oro-facial reactions or nappy rash or eczema (within 2h)

Preventing Food Allergies:

  • Oral tolerance: Regular exposure to allergenic foods in infancy reduces allergy risks.

  • Avoid strict avoidance diets unless medically required.

  • Introduce regular peanut consumption 4 to 11 months

  • Introducing well cooked egg 4 to 6 months

Meeting needs

  • Infants: getting enough protein

  • Toddlers: getting enough but too much milk —> decrease appetite and increase iron deficiency issues

  • Low levels of fibre, omega 3, iron,

  • High level of saturated fat

(7-12 months)

Summary & Key Takeaways

  • By 6 months iron stores are falling

  • Physically ready: head control, ↓Extrusion reflex

  • Demonstrate interest in foods

  • Less chance of allergy

  • Teeth start to emerge- but this does not hold up introduction to solids

  • Cautionary note: hygiene important. Introduce pathogens with foods.

  • Parents or care-givers decide what, when and where foods are eaten.

  • Ten tastes of each new food …

  • Small tastes of separate vegetables rather than mixing or hiding

  • Children eat erratically but daily energy intake remains fairly consistent…