ANTHROPOMETRIC MEASUREMENTS AND INDICES
Nutritional Anthropometry is concerned with the measurements of the variations of physical dimensions and body composition at stages of life cycle and different planes of nutrition. It is a field-oriented method, which can be easily adopted and interpreted.
The basic measurements which should be made on all age groups are weight in kg, length / height and arm circumference in cms. In young children it should be supplemented by measurements of head and chest circumference.
Weight gain is an indicator of growth in children. It is measured with the help of the weighing scale. Body weight should be determined after the first void and before ingestion of food.
The weight for age can be compared with the standards of ICMR and the nutritional status can be interpreted.
Anthropometric Indices : Weight for age The Nutritional status can be interpreted using Gomez Classification as follows Weight > 90% Weight for age. Normal.
76 - 90% Weight for age. Grade I malnutrition.
61 < 75% Weight for age. Grade II malnutrition. < 60% Weight for age. Grade III malnutrition.
Two types of linear measurements are commonly used.
(i) height or length of the whole body
(ii) circumference of the head and the chest.
The height of the individual is the sum of four
components: leg, pelvis, spine and skull.
The height of an individual is measured using a stadiometer.
For infants and children recumbent length (crown - heel length) is measured. The measurement is compared with the standards of the ICMR as given in table 16C to assess nutritional status.
The desirable birth weight and length of an infant is 3 kg and 50 cm respectively. By the time the baby turns the first birth day, the birth weight is doubled and an increment of 25 cm in length is reached.
Head Circumference :
The measurement of head circumference is a standard procedure to detect pathological condition in children. Head circumference is related mainly to brain size. At birth the circumference of head is greater than that of the chest.
Chest Circumference :
The circumference of the head and the chest are about the same at six months of age. After this the skull grows slowly and the chest more rapidly.
Therefore between the ages of six months and five years the chest / head circumference ratio of less than one may be due to failure to develop or due to wasting of muscle and fat of chest.
In nutritional anthropomertry the chest / head circumference ratio is of value in detecting under nutrition in early childhood.
Mid Upper Arm Circumference (MUAC) :
Mid upper arm circumference at birth in a healthy child is between 10 - 11cm. over the first year the increment in MUAC is 3 to 4 cm as the muscles of the arms start to develop. In the preschool age the increase in MUAC is only one cm. Hence there is not much difference between the MUAC of a 3 year old from that of a 5 year old. So MUAC is an age independent index. The field workers in nutrition in our country have fixed the desirable value for MUAC as 12 cm for Indian preschool children.
The WHO has recommended 14 centimeter as a desirable value for MUAC for preschool children.
Hence in screening malnourished children in a community this method is used with ease. When the value of MUAC is less than 12 cm among 1 -5 year old children, they are designated as malnourished.
In the field condition a bangle with a diameter of 4 centimeter can be used as a tool to detect malnutrition. When the bangle moves smoothly over the mid-upper arm of the child, it indicates malnutrition. The bangle test can be conducted with ease in field condition to screen malnourished children.