Foods can be grouped according to the nutrients they contain and the functions they perform in the body. Therefore we have the following classes:
1) Body building foods: these are proteins. They include meat, fish, eggs, milk, beans, etc.
2) Energy foods: these are carbohydrates and fats. Proteins can supply energy but not as mush as carbohydrates and fats. Examples of energy foods are starchy foods such as rice, potatoes, bread, Palm oil, groundnut oil, yam, cassava, etc.
3) Protective foods: these protect the body from diseases. They are vitamins and minerals. Sources include vegetables and fruits.
4) Roughage: this is an important food item. It is indigestible part of foods such as cellulose. It has the following uses:
• it increases the bulk of food.
• it helps digestion and bowel movement.
• it therefore helps to prevent constipation.
No single food contain all the nutrients needed by the body. Some foods contain only one nutrient for example potatoes only carbohydrate. Some foods can contain more than one nutrient and some for example egg contains protein, minerals and some other nutrients. In other to eat all the nutrients we must take meals that are not only mixed but balanced.
A mixed diet is one that contains two or more of the food nutrients.
A balanced diet is one ghat contains all the food nutrients in the correct quantities for a given individual or groups is individuals. Different groups is people for example children, adolescents, pregnant mothers, invalids, the ages, vegetarians, have different nutritional needs.