The deficit in weight for height in a 3-year-old child indicates –
SURVEILLANCE OF GROWTH AND DEVELOPMENT

Surveillance of growth and development is an important component of the routine anticipatory care of children.
The main purpose of growth surveillance is to identify those children who are not growing normally. Surveillance for physical growth can be done in the following ways.

1) Weight for age 

Measurement of weight and rate of gain in weight are the best single parameters for assessing physical growth. The weight should be carefully repeated at intervals:
Birth -1 year → Monthly
The second-year → Every two months
2-5 years → Every 3 months
These measurements when compared with the reference standards of the weight of children of the same age, the trend of growth becomes obvious.
Weight for age can be used to classify malnutrition and determine its prevalence.
80 % of the median weight for age of the reference is cut off point below which children should be considered malnourished.

2)   Weight for age 

Height is a stable measurement of growth as opposed to body weight.
Whereas weight reflects only the present health status of the child, height indicates the events in the past also.

Low height for age :

This is also known as nutritional stunting or dwarfing.
It reflects past or chronic malnutrition.
The cutoff point commonly taken for the diagnosis of stunting is 90 percent of the united states NCHS height for age.

3) Weight for height

Weight in relation to height is now considered more important than weight alone. 
It helps to determine whether a child is within range of normal weight for his height.

Low weight for height

This is also known as nutritional wasting or emaciation (Acute malnutrition).
It is associated with an increased risk of mortality and morbidity.
A child who is less than 70% of the expected weight for height is classed as severely wasted.

4) Head and chest circumference 

Chest circumference
At birth → Less than 2 cm from head circumference
6-9 months →Two measurements become equal
> 6-9 months → Overtakes head circumference
In severely malnourished children this overtaking may be delayed by 3 to 4 years.
Acute malnutrition
Chronic malnutrition
Concomittant acute and chronic
Under weight