Nutrient Intakes in Australian Children
Overweight and obesity doubled in Australia’s school aged children between 1985 and 1995 and while many children are over fed and under exercised, a significant number are not meeting the recommended dietary intakes for some key nutrients. This situation indicates that some children are consuming excessive amounts of kilojoules from foods and drinks which are not providing sufficient quantities of key nutrients.
Recommended Dietary Intakes (RDI)
Recommended dietary intakes are amounts of essential nutrients determined to be adequate to meet the nutritional needs of most healthy people in Australia. RDIs are set at levels higher than the amount known to prevent symptoms of nutrient deficiencies to allow for differences in the absorption and metabolism of nutrients between individuals. They are often used to assess the probability of nutrient deficiencies in population sub-groups, such as in children of different ages. While a level of intake below the RDI does not necessarily indicate a nutrient deficiency exists, health professionals often become concerned when intakes are less than 70% of the RDI.
While RDIs have traditionally been set to prevent nutrient deficiencies, there is now evidence that intakes higher than the RDI for some nutrients may play a preventative role in the development of some cancers and chronic diseases. RDIs in Australia are currently under review and as part of this process it may be appropriate to establish different levels of intake – a minimum level to prevent deficiency states and an optimal level to promote optimum health.
The demand for calcium during the pre-pubertal years is greater than at any other time in life with the skeleton increasing in size by seven fold. Obtaining enough calcium from the diet is the most important nutritional factor affecting bone strength and low calcium intakes during childhood may affect the attainment of peak bone mineral density. Achieving peak bone mineral density in early adulthood is likely to decrease the risk of osteoporosis later in life.
The National Nutrition Survey (conducted by the Australian Bureau of Statistics in 1995) shows 75% of girls and 50% of boys aged 4-7 years obtain less than the RDI for calcium from their diet with 22% and 12% respectively receiving less than 70% of the RDI . Children need the equivalent of 2-3 serves of dairy foods daily to reach the recommended dietary intake for calcium. Good food sources of calcium include:
- Reduced fat milk, yoghurt and cheese (full cream varieties are recommended for children under five years of age).
- Fortified soy milk and yoghurt.
- Fortified breakfast cereals.
- Sardines and salmon with soft bones.
- Almonds and dried figs
Iron deficiency is the single most common nutrient deficiency in the world and is particularly prevalent in infants, children and women. Australia is no exception with as many as 35% of toddlers being iron deficient . In addition, the National Nutrition Survey shows 62% of girls and 21% of boys aged 12-15 years do not meet the RDI for iron with 22% and 4% respectively not meeting 70% of the RDI. Iron deficiency is often asymptomatic but can be associated with impaired physical performance as well as affecting memory, concentration and learning. Sufficient iron is essential to maintain resistance to infections and to enable normal growth and development.
Children need to eat sufficient amounts of breads, cereals and green leafy vegetables along with ½ to 1½ serves of meat or alternatives daily to help meet their iron requirements. Good food sources of iron include:
- Lean red meat – beef and lamb Pork, chicken and fish
- Mussels and oysters
- Legumes – lentils, dried peas, baked beans
- Iron fortified breakfast cereals
- Green leafy vegetables
- Dried fruits – dates, raisins, apricots
The strength of the immune system is closely linked to zinc status as zinc plays a role in wound healing and in fighting infections. Zinc is also required to help make some of the body’s proteins and plays an important role in growth. Long term, mild zinc deficiency can lead to delayed wound healing, impaired immune function and problems with taste and smell acuity.
The National Nutrition Survey shows nearly 9% of boys and 13% of girls aged 4 to 7 years, and 33% of boys and 70% of girls aged 8-11 years do not meet the RDI for zinc. Good food sources of zinc include:
- Seafood and chicken
- Beef and lamb
- Seeds and nuts
- Soybeans, lentils and tofu
- Wholemeal pasta and brown rice
The National Nutrition Survey shows 20% of boys and 20% of girls aged 8 to 11 years do not meet the RDI for vitamin A with 6% and 4% respectively obtaining less than 70% of the RDI. Vitamin A is essential during growth as it plays a role in cell division. It is also important to help make the cells required by the skin and membranes within the body which in turn play a role in preventing some infections. Vitamin A is required for good vision and may also be essential for taste, hearing and appetite.
Vitamin A comes from food in different forms – either as retinol or as carotenoids, the most important carotenoid being beta-carotene. Retinol is found only in animal foods while carotenoids are found mainly in plant foods such as fruit and vegetables. To achieve adequate amounts of vitamin A in the diet, children should be encouraged to include 2-3 serves of dairy foods, 2-5 serves of vegetables and 1-2 serves of fruit in their daily diet. Good food sources of vitamin A include:
- Full cream milk, cheese and yoghurt Fatty fish such as salmon and mackerel
- Yellow and orange fruit and vegetables such as apricots, rockmelon, paw paw, mango, carrots, pumpkin and sweet potato.
- Green leafy vegetables such as asparagus, lettuce, cabbage and spinach.
Prepared by Sharon Natoli, Accredited Practising Dietitian, Food and Nutrition Australia Pty Ltd.