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Nutrition is interpreted as:
As recently as the 1960s doctors told their patients that nutrition had little to do with their health. Now we know otherwise: "you are what you eat!" More specifically, in humans, the matter which comprises the cells of the body (except those cells produced before birth) is acquired from food in the stomach. Not all the food matter in the stomach can be used for the body; the matter that is left over as waste is removed.
Study in this field must take into account the state of the animal before ingestion and after digestion as well as the chemical content of the food and the waste. The specific types of matter (chemicals) that are absorbed by the body can be determined by comparing the waste to the food. The effect that the absorbed matter has on the body can be determined by finding the difference between the pre ingestion state and the post digestion state.
The effect may only be discernible after an extended period of time in which all food and ingestion must be exactly regulated and all waste must be analyzed. The number of active variables involved in this type of experimentation is very high. This makes scientifically valid nutritional study very time consuming which accounts for why a proper science of human nutrition is rather new.
This new science has rapidly expanded. Vitamins were first written about in 1912, by Sir Frederick Gowland Hopkins, who was knighted and received the Nobel Prize in 1929 for his achievements.
In the 20th century, after clarification of the nature and role of proteins, carbohydrates, vitamins and minerals, it was thought that we had adequate knowledge about the elements of food. Food was seen as the fuel, and we simply had to have enough of its ingredients in order to go on living. However, there followed an accelerating series of discoveries starting with fibreDietary fibers are long-chain carbohydrates ( polysaccharides) that are indigestible by the human digestive tract. The value of dietary fiber is that it provides bulk to the bolus moving through the digestive tract. There are two great advantages to this:, which has revealed increasingly large gaps in our knowledge about the role of food in our health and proper functioning.
We now know that there are many thousands of phytochemicals in our food, each of them performing an essential role in the proper functioning of our bodies. Furthermore, it is thought that there are many more phytochemicals and other components of food to be discovered. There are also enzymes which play an important part in nutrition: these are chemical catalysts in our food and also produced in our digestive system. They are vitally important in all the metabolic activity in our bodies.
Antioxidants are another recent discovery. Using energy in our bodies often has damaging side effects on cells, and certain food elements such as vitamin C have been seen to be vital in protecting against the aging effect of this oxidizing damage. Recently the health benefits of vitamin E have been called into question.The balance of essential fatty acidsEssential fatty acids are fatty acids that are required in the human diet. This means they cannot be synthesized by the body from other fatty acids and must be obtained from food. These fatty acids were originally designated as Vitamin F until it was real (linoleic and linolenic oil) has been discovered to be crucial in maintaining good health. This involves omega 3 and omega 6 oils, as well as the need to minimise hydrogenated fats which contain heavy metals.
Results are emerging to indicate that phytoestrogensPhytoestrogens are trace substances in our food which mimic and supplement the action of the body's own hormone, estrogen (sometimes spelt as 'oestrogen'). They are a comparatively recent discovery, and researchers are still exploring the nutritional role in our food are related to the avoidance of metabolic syndrome, the regulation of cholestorol, and maintenance of bone density. (See medical abstract, and references Merrit, 2004, Mei 2001 below).
It is now also known that the human digestion system contains a population of a range of bacteria which are essential to digestion, and which are also affected by the food we eat.
The previous mechanistic view of food as fuel, and the simplistic notion that protein, carbohydrate etc. were each obtained from one type of food (the meat and two veg model) has all but been replaced. Increasing complexity means that nutrition researchers today advocate a holistic approach. They readily admit that there are many nutrients and other factors we don't know enough about, and that most foods contain most types of nutrients in various proportion. Provided excess is avoided, particularly of carbohydrates and hydrogenated fats, then it has been shown that our needs are best met through eating a wide variety of fresh, unprocessed and unmanufactured food.
The Institute for Food Additives and Ingredients gives the following information:
People in Japan eat far more salt than people in the west.
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