Food may be defined as anything eaten or drunk which meets the needs for energy, building, regulation and protection of the body.
Food is the raw material from which our bodies are made. It is that which nourishes the body anything eating or drunk or can be absorbed by the body to be used as energy source, body building, regulating and protecting material. It is essential for the sustainence of life.
Nutrition is the science of foods, the nutrients and other substances therein, their action, their interaction & balance in relationship to health and disease, the processes by which the Organism ingests, digests, absorbs, transports and utilises nutrients and disposes the end products.
Nutrition science is the area of knowledge regarding the role of food in maintenance of health.
Health is defined by WHO as the state of complete physical mental and social well being and not merely the absence of disease and infirmity .
Nutrients at the constituents in food that must be supplied to the body in suitable amounts these include carbohydrates fats proteins minerals vitamins and water a nutrient must accomplish at least one of the following functions
- Energy yielding – carbohydrates and fats
- Bodybuilding and repairing tissues – proteins
- Protection and regulation (body process) – vitamins and minerals, water
Nutritional needs of the body:
Energy is the primary need it is required to perform both the internal and external physical activity of the body.energy is required not only to perform work but also when the person is sleeping, taking rest, it is required for pain, liver, kidney and other organs to function properly.
Energy is mainly obtained from carbohydrates and fats. The requirement of carbohydrate for a normal and healthy individual is around 60 grams per day. And 70% of energy requirement should come from carbohydrates. The requirements of fats for a normal healthy person is around 20 gram per day and about 30% of the energy requirement should come from fats.
Growth needs and maintenance and repair:
Life starts as a single cell in grows to multicellular well developed body. Food is required for the growth and development process. Growth is the phenomena in which the body undergoes a change both physical and mental for which food is very much essential. Food is also required by the body to maintain itself. Body tissues both internally and externally undergo wear and tear. Food is required for wound healing, body repair and synthesis of new cells.
Bodybuilding and tissue repair was brought about by proteins. Requirement of proteins for a normal healthy individual is about 1gm/kg body weight. 60g for males and 1g/kg between (55g) for females. This requirement again increases during pregnancy and lactation.
Regulatory needs: For the regulation of various organ system and chemical reaction of the body such as regulation of heartbeat, supply of blood et cetera food is needed. Certain components such as hormones enzymes helps in the regulation of various body systems which in turn require Food for their synthesis. Regulatory functions is carried out by a number of vitamin and mineral and requirement of the vitamin and mineral vary for each vitamins and minerals.
Example : Vitamin A -> 750 µg/day, Calcium -> 600 µg/day