- Nutrients are substances in food that serve one or more of the following purposes
- Provide a source of energy
- Regulate chemical reactions in the body
- To stay healthy humans need
- macronutrients (carbohydrates, proteins and fats) and
- micronutrients (mineral salts and vitamins) along with water and fibre.
- Macronutrients form the major part of diet.
- Carbohydrates provide energy.
- Carbohydrates are broken down into monosaccharides and used in cellular respiration to release energy.
- Some glucose is converted to glycogen and is stored in liver, muscles and brain.
- Any excess carbohydrate is converted to fat and stored in various parts of the body.
- We get carbohydrates from:
- Foods high in protein are necessary to enable us to grow and repair muscle.
Functions of Proteins
- Form major structural material in body.
- Act as a source of energy.
- Allow internal communications system to function.
- Drive chemical reactions needed for life.
- Plant fat- Oils (sunflower, corn, soya, etc.) and margarines
- Animal fat- Solids (butter, lard, cheese)
Functions of Lipids
- Provide large amounts of energy.
- Compose the structure of cell membranes.
- Regulate cellular processes.
- Forms an insulating layer under the skin to keep the body warm.
- Fibre is found in the form of plant material that we cannot absorb and is passed through the body.
- It aids in intestinal digestion, binds cholesterol and passes it out of the body along with other waste products.
- Vegetables and hard fruits
- The human body is 75% water.
- In ordinary living, we lose between 2 and 3 liters a day through our urine, sweating and exhaling.
- When exercising the body loses even more water, and is at risk of dehydration if it is not replaced.
Functions of Water
- Medium that transports nutrients, gases and waste products.
- Serves as environment where chemical reactions occur.
- Regulates body temperature.
- They do NOT provide structure or energy.
- Promote growth & development.
- Protect body from damaging effects of toxic compounds.
- Build and maintain tissues.
- Assist in using energy from carbohydrates, protein, and lipids.
- Assist in disease prevention and treatment.
Classification of Vitamins
- Lack of minerals in diet can lead to a variety of serious conditions.
- Calcium is needed for the formation of your skeleton and teeth, for muscles to contract and for blood clotting to take place.
- Sodium is needed for nerves to work properly, for muscular contraction and to maintain heart beat.