Quick questions on Dietary needs across the life cycle - O-Level Food and Nutrition

Children are growing and active, so relative to their size they need plenty of energy, protein for growth, and calcium with vitamin D for developing bones and teeth. Iron is needed for healthy blood. Because their stomachs are small, regular meals and nutritious snacks matter, and too much sugar should be avoided to protect teeth and prevent early weight gain.

Teenagers go through a rapid growth spurt and are often very active, giving them some of the highest energy and nutrient needs of any group. Key nutrients are protein (growth and repair), calcium and vitamin D (to build peak bone mass), and iron, which is especially important for girls who lose iron during menstruation and so are at higher risk of anaemia.

In adulthood the focus shifts from growth to maintenance and the prevention of diet-related disease. Energy needs depend on activity and should be matched to avoid weight gain, with attention to keeping saturated fat, sugar and salt moderate and fibre high.

Older adults are usually less active and often eat less, so energy needs fall but the need for nutrients stays high - this is called nutrient-dense eating. They are at risk of low calcium and vitamin D (weak bones, osteoporosis), low iron (anaemia), and low fibre and fluid (constipation). Soft, easy-to-chew, nutrient-rich foods and enough fluids are important.