Classification of Foods
Based on the nutrients in food, food substances are classified into:
- Fats and oil (lipids)
Generally, all foods are categorized into:
1. Energy-giving food – Carbohydrates and Fats and Oil.
2. Bodybuilding food – Protein
3. Health preserving food – Vitamins and Minerals
Below is a list of different classifications of nutrients, their sources, functions and composition.
|Protein||Meat, milk, fish, poultry, beans, eggs, cheese||Supports growth and maintains healthy body cells||Carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus|
|Carbohydrates||Cereal, potatoes yam, bread, maize, sugar||Provides main source of energy for the energy||Carbon, hydrogen, oxygen|
|Fats and oil||Vegetable oil, butter, palm-oil, margarine||Provides energy for the body, it also keeps the body warm||Carbon, hydrogen, oxygen|
|Vitamins||Liver, carrots, oranges, grapes, milk, cheese, fruits||Protects the body against diseases, promotes chemical reaction in the body||Varying in components e.g vitamin A, Vitamin E|
|Minerals||Liver, meat, poultry, fish||Regulates the body’s metabolism||Potassium, iron, calcium|
|Water||Most food we eat contain water e.g fruits ||Helps with body process such as digestion, makes up 60% of the human adult body||Hydrogen, oxygen|
Vitamins: Promote chemical reactions in the body
The various types of vitamins, sources, functions, effects of deficiency are seen below.
|Vitamins||Sources||Functions||Effects of deficiency|
|1||A (Retinol)||Liver, eggs, milk, fish, liver oil, tomatoes, mangoes||For healthy skin and normal vision||Dry skin, night blindness|
|2||B complex||Yeast, palm wine, beans, eggs, tomatoes, groundnut||For normal growth, for normal working of heart and nervous system||Reduced growth, beriberi|
|3||C (Ascorbic acid)||Citrus fruits e.g oranges, tomatoes, guava, pawpaw, green vegetables||Maintenance of connective tissue bones, help to resist infections||Slow healing of wounds, scurvy|
|4||D(Calciferol)||Milk, egg yolk, liver, fish liver oil||Facilitates absorption of calcium and phosphorous in the intestine, for hardening of bones||Rickets (poor bone and teeth formation)|
|5||E (Tocopherol)||Leafy vegetables, oils, e;g palm oil, eggs||Required for the proper function of many organs in the body. It is also an antioxidant. ||Sterility|
|6.||K||Green vegetables||Synthesis of blood clotting factors||Slow clotting of blood leading to severe bleeding|
Minerals regulate the metabolism of the body. Their sources, types, and deficiency symptoms are written below:
|1||Sodium||Salt, meat, egg, milk||Permeability, for normal cell membrane||Dehydration, kidney failure|
|2||Chlorine||Salt||Maintains correct osmotic pressure of body fluids||Muscle cramps|
|3||Potassium||All natural foods||Permeability, for normal cell membrane||Loss of bone minerals, muscle paralysis|
|4||Calcium||Diary products e.g milk, cheese, eggs, vegetables ||Bone formation and blood clotting softening of bones||Rickets|
|5.||Phosphorous||Dairy products, meat, beans, plantain||Bone formation and general metabolism|
|6.||Magnesium||Leafy vegetables, nuts, seafoods||A major component of bones||Teeth muscle, muscle contraction|
|7||Iron||Liver, egg, meat, green vegetable||Formation of haemoglobin in red blood cells||Anaemia|
|8.||Iodine||Seafood, iodized table salts||The body needs iodine to make thyroid hormones. These hormones control the body’s metabolism and many other important functions.||Goiter, cretinism|
|9.||Fluorine||Milk||Hardening of bones and teeth||Dental caries|
An excessive loss of water from the body is called dehydration measured with a calorimeter.
Factors that Determine Nutrients needs of an Individual:
- The amount of physical exercise
Specific health conditions such as pregnancy, breastfeeding, illness, or drug use, make unusual demands on the body and increases its need for nutrients.