Human body needs food for various purposes. Food consumed by humans are of different types and a balanced diet is needed for all practical purposes, vitamins, proteins carbohydrates and minerals are primarily obtained from cereals, fruits, vegetables, pulses and spices, milk, butter, meat and eggs all of which obtained from different types of plants and animals. These are our main food resource. A large number of items are consumed by human either in their natural states or after proper processing and cooking.
The food consumed by human is influenced by wide range of cultural and individual differences, mainly due to ecological as well as personal reasons. The source of much of the food consumed by man is terrestrial agricultural, which represents the most manipulated of all the non-urban ecosystems. There are two main types of agriculture (1) Crop agriculture in which plant production is harvested for use by man and (2) Animal agricultural where a crop from highly manipulated ecosystem is fed to domesticated animals.
Food consumption pattern is different in different regions. The most important feature is that rice to the staple food for most Asians. In general a strong and healthy human consumes about 1.4 kg of food every day. Such a food serves as a source of energy and replacement of uses.
However, the excessive use of potential chemicals is being used at various stages of cultivation. By doing so, the food products are contaminated. The persistent pesticides are considered to be damaging and toxic. As a result of such a practice human population has to face a great problem so for as sources of food are concerned. Although by undergoing several good practices before cooking or consuming the food products it has been observed several kinds of diseases affect the health.
In addition to pesticide problems, several heavy metals or their compounds have also led to serve toxicity problems and most of them have provide pathways for several fatal diseases, some examples of such an effect are cereals, spinach are the major sources of cadmium, fruits and vegetables account for 80% of lead intake, meat, fish, poultry and cereals constitute major sources of selenium and the dietary intake of mercury arises from the consumption of fish: when food sources supply heavy metals at levels higher than their daily tolerance limit, constituting, they cause a source of health disorders.
New Sources of Food :
It has been conduced that even if the rapid development of conventional agriculture is sustained protein deficiency will continue to exist. Accordingly a search is in progress for supplementary sources of plant and animal proteins. Amongst these animal protein has been considered to be of more importance because of the similar amino acid composition of man. Besides, animal's flesh has the advantage that it more easily assailable. In case the animals are to be avoided, a food source which will yield plant protein in a digestible form or from which the majority of cellulose has been removed, fungi can be preferred.
These can be easily assimilated and contains a good amount of protein. Other sources are fish and beef. The advantage of using mushroom is that it does not absorb much human or fossil energy in production can be grown independently of environment factors.
Young seabirds, reptiles, amphibians, insects, molluscs, rodents and many other animals can be utilized as food. Fresh water and brackish water fish are other sources of animal proteins. It has been found that marine and fresh water fisheries provide best sources of animal protein
