Explain how nutritional requirements change through the life cycle, including pregnancy, infancy, childhood, adolescence, adulthood and older age

What this dot point is asking

You need to explain how nutritional needs differ at each life stage and give the reasons, focusing on the nutrients that matter most at each point.

Pregnancy and lactation

During pregnancy the body supports a growing baby, so several needs rise. Folate (folic acid) is critical in early pregnancy to reduce the risk of neural tube defects. Iron needs increase to build extra blood for mother and baby, and iodine supports the baby's brain development. Energy needs rise modestly, mainly in later pregnancy, not from the start.

During lactation (breastfeeding), energy and fluid needs are higher again to produce milk, and a varied diet supports both mother and infant.

Infancy

Infants grow faster than at any other stage, so their needs per kilogram of body weight are the highest in the whole life cycle. Breast milk is recommended as the ideal first food because it supplies the right nutrients, antibodies for immunity and is easy to digest; infant formula is the alternative. From around six months, solid foods are introduced alongside milk to add iron and other nutrients and to develop eating skills.

Childhood and adolescence

Children need steady energy and nutrients for continued growth, including calcium for bones and iron for blood. Establishing varied, healthy eating habits early matters for life.

Adolescents experience a growth spurt and rising activity, so energy needs peak. Calcium and vitamin D are vital for building peak bone mass, and iron needs rise, especially for menstruating girls. Appetite is large, but the food chosen still needs to be nutrient rich, not just high in energy.

Adulthood

In adulthood growth has finished, so the focus shifts to maintenance: enough energy to match activity, balanced macronutrients, and adequate micronutrients to stay healthy and lower the risk of diet-related disease. Energy needs depend on activity level, and a positive energy balance over time leads to weight gain.

Older age

In older adults, total energy needs often fall because activity and muscle mass decline, yet the need for several nutrients stays the same or rises. Calcium and vitamin D remain important to protect bones against osteoporosis, and protein helps preserve muscle. Appetite, taste, dental health and absorption can all decline, so foods need to be nutrient dense, supplying plenty of nutrients per kilojoule.

Why this matters

Understanding life-cycle nutrition lets you judge whether a diet suits a particular person rather than an average adult. The same meal can be ideal for a teenager and too energy dense for an inactive older adult. This links directly to the dietary guidelines and to evaluating real case studies in the examination.

In short, nutritional requirements track growth and activity across the life cycle, with extra demands in pregnancy, infancy and adolescence, maintenance in adulthood, and a shift to nutrient-dense eating in older age.