Nutrition Across the Lifespan
Nutrition Across the Lifespan tests nutrient needs and feeding practices from preconception through older adulthood. Expect stage-specific risks, critical periods, and safe feeding boundaries rather than adult guidance applied uniformly.
Core rules
- Preconception and early pregnancy require adequate folate; 400 mcg/day folic acid is commonly recommended before conception and in early pregnancy to reduce neural tube defect risk.
- Pregnancy energy needs rise modestly, not “for two.” Common estimates are about +340 kcal/day in the second trimester and +450 kcal/day in the third, alongside higher protein, iron, iodine, and choline needs.
- Exclusive breastfeeding is recommended for about the first 6 months, with complementary foods starting around 6 months. Infants need vitamin D supplementation, commonly 10 mcg (400 IU)/day, and vitamin K at birth.
- Older adults often need more protein, about 1.0–1.2 g/kg/day, plus adequate calcium, vitamin D, fiber, and fluids to counter sarcopenia, bone loss, and dehydration risk.
Worked example
A 65 kg older adult needs 1.0–1.2 g/kg protein = 65–78 g/day. At 0.8 g/kg, intake would be 52 g/day, which may be insufficient during illness or low appetite. The higher target must be distributed across meals and matched with energy intake to support muscle protein synthesis.
Traps
Do not advise honey for infants under 12 months because of botulism risk. Do not use cow's milk as the main drink before 12 months. Do not interpret “eating for two” as doubling energy. Do not apply adult protein requirements to frail older adults without considering muscle preservation.