Chapter 2


This section has examined recent trends in the world food economy, and ways in which food
consumption in particular shows systematic patterns and variation which can be used to
predict likely changes in demand. These economic forces do not work themselves out in a
vacuum. The next section looks at the policy objectives which may determine the social, /
institutional and regulatory environment within which food security has to be achieved.

3. Direct Measures of Nutritional Status

The measurements which have been discussed so far are measurements of intake and
availability. They are useful in trying to describe the economic and social factors which lead
to food insecurity. However, to identify the most vulnerable members of society
measurements of outcome have to be employed. The most common of these are direct
measures of physical size and well-being.

3.1 Anthropometric measures

Anthropometric indicators, which are usually based on estimates of the total mass of body
tissues, such as weight or arm circumference, are commonly accepted measures of the
nutritional well-being of an individual. Unlike other measurements which have been
discussed, these can only be measured at the individual level, not at household level. They
can however be aggregated to give information about a specific population.

In one sense, they are the ultimate outcome indicators of food system of a country, but as
was shown in Figure 1 they are affected by both food and non-food elements such as illness
and parasitic disease, and have to be interpreted with care. Their significance will be
discussed in the next section.

Anthropometric measurements are most commonly taken on young children. This is for a
number of reasons. They are often seen to be amongst the most vulnerable members of
society and therefore their nutritional status is a more sensitive indicator of well-being than
that of adults. Certainly very young children who have relatively large energy requirements
for growth, show the effects of low energy intakes more clearly than adults, who may adapt
to low intakes by reducing activity levels. Until recently, there has been more information to
help the interpretation of anthropometric data in children, in terms being able to associate
low measurements with an increased risk of morbidity and death. However, there are
indicators of adult nutrition which are quite sensitive to nutritional deprivation. The
incidence of low-birth weight babies is clearly linked to maternal malnutrition. The Body
Mass Index (BMI) is increasingly used as an indicator of adult nutrition in developing
countries as well as industrialized nations. (This is described in more detail later in this
section).

The most commonly used anthropometric indicators in children are weight-for-age, height-
for-age, weight-for-height and mid-upper arm circumference. In all cases, measurements
are taken and compared to reference standards, the mean or median values of body
dimensions in a well fed and cared for population. As with nutrient intakes, there is a certain
distribution of weights in a well-fed population for genetic reasons, and cut-off points are
determined on the basis of this distribution. Thus if a child is less than 2 standard deviations