Chapter 2


Because of their relatively high energy requirements, young children are much more
vulnerable to energy deficiencies than adults. At this period of their lives, malnutrition can
affect both physical, and eventually mental development.

1.3.2 Pregnancy

Pregnancy increases the energy requirements of the mother by about 15%. For most of the
other nutrients, requirements are also higher. If the mother is malnourished before or during
pregnancy, she may give birth to a low-birth weight baby, whose risk of premature death will
be greater.

1.3.3 Lactation

In order to produce enough milk without lowering her own body reserves, the lactating
woman must increase her energy intake by an additional 10% over and above the increase
recommended during pregnancy.

1.3.4 Physical activity

The more active an individual is, the higher his energy requirement. In rural areas,
requirements vary according to the agricultural seasons (land clearance, sowing, weeding and
harvest). In general, individuals are normally classified as engaging in light, moderate or
heavy physical activity, according to lifestyle.

1.3.5 Body weight

Along with physical activity, body weight constitutes the major item of expenditure of an
adult. In practice, body weight determines the basal metabolic rate (BMR), that is the
minimum quantity of energy necessary to support the body at rest. A method for calculating
BMR will be discussed in section 1.4.

1.3.6 Infection and Rehabilitation

Infections can increase the loss of nitrogen and of certain vitamins and minerals from the
body, and energy expenditure. This means that requirements for energy, protein and other
nutrients will be increased during infection and recovery. Appetite is often reduced during
infections. Repeated episodes of diarrhoea can lead to dehydration and severe malnutrition in
an already vulnerable child. In Africa, measles can often be a precursor of severe protein-
energy malnutrition in children.

1.4 Reference Nutrient Intakes (RNI)

As discussed above, RNIs are used to assess the adequacy of diet for both individuals, but
more importantly as far as food security is concerned, the adequacy of the supply of nutrients,
in particular energy and protein, available to the population of a country, and to which they
have access.


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