What is food?  
  What happens to the food we eat?  
Our nutrient needs
  Energy balance  
  Nutritional status  
  Laws & labels  
  Additives & colours  
  Toxicity in food  
  Processing food  
  Stability of food nutrients  
  Storage life of foods  
  Food- associated health problems  

- FIGURE 6 -


infants | children | adolescents | adults | pregnancy | lactation | elderly


  • With weaning or with a change from infant formulas to cow's milk at around 6 months of age, there is a reduced intake of vitamins C and D and iron.
  • Adequate exposure to sunlight usually prevents vitamin D deficiency or rickets.
  • Additional sources of vitamin C and iron-containing foods are recommended at this time.
  • Fluoride may be needed where water is not fluoridated.

Infant eatingCHILDREN

  • Nutrient needs during childhood are determined both by growth and physical activityFind out more about this term.
  • A developing knowledge of and interest in food and its preparation will help children choose from a wide variety of foods.
  • The principle nutritional problems of childhood in developed countries are obesity on the one hand and underweight on the other, dental caries (tooth decay) and, for a few children, food sensitivity. Food sensitivity can show up as eczema, asthma, bowel disturbances, and, possibly, behavioural problems. A lack of foods containing dietary fibre can also lead to constipation.

ADOLESCENTSFind out more about this term

  • In early adolescence or puberty there is a marked increase in rate of growth, and therefore in energy and nutrient needs. Thus foods that are energy dense (see Energy Balance/Energy Density) can be tolerated at this time and nutrient-dense foods (see Energy Balance/Nutrient Density) should be encouraged. Some foods such as nuts and meat are both energy and nutrient dense.

adult woman eatingADULTS

  • The adult is at nutritional risk because of changing food patterns moving from the parental home, getting a job (or not having a job), and changing patterns of physical activity. There are problems of obesity, hardening of the arteries (atherosclerosis), high blood pressure and proneness to certain cancers. To minimize these health risks the adult should maintain physical activity and control intake of energy-dense foods (especially fats) and salt.


  • Energy and nutrient needs increase during pregnancy to meet the needs of the developing foetus - by about an additional 10 per cent. It is especially important in pregnancy to be neither overweight nor underweight. Nevertheless, pregnancy itself is not the time to be making efforts to reduce weight, because of risks to the foetus. After pregnancy, there is a greater risk of putting on excess weight and this should be guarded against.
  • During pregnancy, cravings for particular foods can occur. The pregnant woman should not let these displace more important food items from her diet.
  • The pregnant teenager is at extra risk because she has to meet the nutritional needs of her own growth as well as those of the foetus.
  • Essential nutrients that tend to be depleted during pregnancy include protein, calcium, iron and folacin.
  • Alcohol intake should be kept to a minimum because of possible harmful effects on the unborn child.


  • Breast-feeding increases the mother's nutrient and energy needs by about 20 per cent. The more milk produced, the greater the energy and nutrient requirements.
  • When a mother is breast-feeding, calcium and vitamin C are especially important, as these are present in greater concentrations in breast milk than are generally found in the diet.

elderly woman shoppingELDERLY

  • When you are elderly, nutrition is an especially important factor in your diet.
  • In approaching retirement, it is important to be as physically active as possible. Then you will have an appetite to eat the food you need to provide you with all the essential nutrients. Once energy intake falls below about 1200 kilocalories (5000 kilojoules), it is difficult to get all your essential nutrient needs from food.
  • If you are obese, you will be less healthy and your extra weight will contribute to problems of arthritis, especially in joints such as hips and knees, which bear the weight.
  • If you are well and active, your opportunities for independent shopping and food preparation are greater, and these contribute to your nutritional well-being.
Food Facts
- Our nutrient needs
- How our nutrient needs are assessed
- Recommended dietary intakes
5: How the human diet has changed
Our nutrient needs change with age
7: Recommended dietary intakes for different groups
8: Recommended daily dietary intakes in some developed countries
9: Estimated safe and adequate range of daily dietary intakes
10: How to check your intake of a particular nutrient