Human Development across the Lifespan
This domain examines physical, cognitive, language and social-emotional development from conception to later life, and how nutritional and care needs change at each stage. Expect questions that link a stage of the lifespan to a specific requirement and ask you to justify it.
Milestones and growth
- Development follows a sequence (cephalocaudal, proximodistal) but the pace varies; milestones are ranges, not deadlines.
- Growth is monitored against WHO growth standards using centiles. A single low point is less concerning than a child crossing two centile lines downwards over time.
Stage-specific requirements
- Infancy: exclusive milk feeds to around 6 months; complementary foods from about 6 months (not before 17 weeks) because iron stores and energy needs outpace milk alone. No honey under 12 months (infant botulism risk). Vitamin D 8.5–10 µg/day for infants.
- Adolescence: peak calcium and iron needs, especially for menstruating girls; risk of skipping breakfast and dieting.
- Pregnancy: folate 400 µg pre-conception, adequate iron and iodine, no alcohol, avoid listeria-risk foods.
- Later life: energy needs fall while protein, calcium, vitamin D, B12 and fluid needs stay high; sarcopenia, constipation and dehydration are key concerns.
Theory to apply
Piaget (sensorimotor to formal operational), Bowlby's attachment, Erikson's psychosocial stages, and Duvall's family life cycle stages, which reappear in resource management.
Worked example
A 9-month-old's weight has fallen from the 50th to the 9th centile in three months while length and head circumference track normally. Reasoning: isolated weight faltering suggests inadequate energy intake or absorption rather than a constitutional pattern - review weaning texture and energy density, feeding behaviour, illness and coeliac disease, and refer. Do not simply advise 'more food'.
Traps
- Treating milestone ages as fixed pass/fail limits.
- Assuming a heavier infant is a healthier infant.
- Forgetting that energy needs per kilogram fall with age while nutrient density must rise.
- Weaning too early (immature gut, allergy risk) or too late (iron depletion, feeding difficulties).