A balanced diet contains all nutrients required for health in appropriate proportions,and is normally achieved by eating a variety of foods. This is because no single food contains the correct proportions of all essential nutrients. If any nutrient is eaten in excess,or is deficienct,health may be adversely affected. For example,a high-energy diet can lead to obesity,and an iron-deficient one to anaemia.
A balanced diet is important in maintaining a healthy body weight,which can be assessed by calculating body mass index.
A balanced diet requires a certain amount of knowledge and planning. An important dietary consideration is the amount of energy required. This should meet individual requirements. Daily energy requirements depend on several factors including basal metabolic rate,age,gender and activity levels. Dietary carbohydrates,fats and proteins are the principal energy sources and fat is the most concentrated form. Dietary energy is correctly expressed in joules or kilojoules.
Recommendations for daily food intake sort foods of similar origins and nutritional values into food groups,and advise that a certain proportion from each group to be eaten daily. The five food groups are:
- Bread,rice,potatoes,pasta.
- Milk and dairy foods.
- Foods and drinks high in fat and /or sugar.
- Meat,fish,eggs,beans.
- Fruits and vegetables.
