Nutrition: Health Significance, Under Nutrition, Malnutrition And Laboratory Investigations In Nutrition

Nutrition encompasses the intake of exogenous substances supplied in the diet and their transformation into substances necessary for the maintenance of life, growth, normal functioning of the organs, and production of energy. When under nutrition is rampant in the developing countries, the affluent ones are facing the problems of over- eating and obesity. Mexico though happens to counteract this principle as it is now the fattest nation (38%), then the united states (37%). In places like India, the situation is mixed. Large sections of the population are undernourished while about 10% of Indian subjects are obese. The term “malnutrition” covers a broad spectrum of disorders ranging from undernutrition to overnutrition.

Assessment Of Nutritional Status

Nutrition of communities can be assessed by large surveys. These surverys are of epidemiological importance. The methods employed to assess the nutritional status in communities are listed below:

1. Studies on food production or total food availability in relation to total food needs.
2. Measurement of food and nutrient intake.
3. Studies on dietary habits and practices.
4. Special studies on foods to assess biological value and prevalence of interfering substances like toxins and goitrogens.
5. Studies based on socio-cultural parameters.
6. Vital statistics like morbidity and mortality rates.
7. Studies on health conditions, indirectly related to the nutritional status of the population such as infections and parasitic diseases.
8. Studies on health conditions indirectly related to the nutritional status of the population such as infections and parasitic diseases.

Nutrition in individuals can be assessed by clinical examination, anthropometric measurements, and biochemical and other laboratory tests.

Anthropometry, which involves measurement of growth and physical developments, is particularly useful in children. The most commonly employed measurements are: height (linear growth), weight (body mass), head circumference (possible relationship to mental development), mid-arm circumference (variations being mainly due to changes in muscle mass and fat calories), chest circumference and skin fold thickness (fat calories).

The measurements are related to expected standards for age. When the exact age of the child is not known, age independent indices are made use of.

Laboratory Examinations

At present, sensitive methods are available for the accurate determination of vitamins and tace elements in body fluids and tissues, but these are expensive and cannot be employed universally. Moreover, the values of nutrients in blood and tissues show a wide range of levels in normal individuals. No test is specific for a particular kind of malnutrition. Conditions of collection, storage, and technique of estimation can all introduce variations. Recently, the importance of chemical analysis of the hair in determining levels of trace elements has been recognized. The advantages are: it reflects the variation in the level of trace element over a long period and the hair is easy to be preserved and transported of which these materials are concentrated in the hair.