A ,


Chapter 2


by the sum of column B. This figure can then be used to make comparisons at a national
level, for example in a food balance sheet, as will be discussed in section 2.1. Care has to be
take4 not to use these kinds of figures inappropriately by, for example, comparing them to j
measures taken at the population level, without taking into consideration the inequality in the
distribution of food at the inter and intra- household level.

1.4.2 RNIs for protein

Food proteins provide amino acids for the synthesis of body proteins and nitrogen for the
synthesis of many other tissue constituents. The body is in a dynamic state, with proteins being
broken down and released on a daily basis. The body needs to replace these proteins, even after
growth has stopped, and the body has reached its adult size,

Protein can be broken down into twenty amino acids, of which ten cannot be synthesised by the
human body but are necessary for growth and maintenance. These are known as essential
amino acids and they have to be provided from the regular diet. The other ten can be
synthesised by the body and therefore do not need to be ingested in the diet.

RNIs for protein have been falling over time, as understanding of the use of protein in the body
has improved. Previously recommendations were based on patterns of protein intake in healthy
populations, but now they are mainly based on nitrogen balance studies, which look at the
turnover of nitrogen, resulting-from the breakdown of protein in the body. Thus the RNI is now
based on measures of need.

The protein RNI has been set for all adults aged 19 years and over at 0.75g/kg/day. In other
words, it is set in relationship to body weight. This assumes that the protein is of high quality,
i.e. that the essential amino acid composition in the food protein is close to the human body's
need, This will be the case in a mixed diet, composed of a mixture of animal and vegetable
protein, particularly containing a reasonable proportion of milk, eggs, meat gnd fish, When a
ligh proportion of protein ingested comes from a few vegetable sources, such as sorghum,
millet or legumes, then a higher intake will be necessary to ensure an adequate intake of all the
essential amino acids. It has been suggested that for the typical African diet that the RNI should
be closer to I g/kg/day.

RNIs for children and pregnant and lactating women are higher than the standard adult figure,
to allow for growth in children, the growth of foetal and maternal tissue in pregnant women
and breast milk production in lactating women. It is recommended that pregnant women add an
additional 6g/day to the RNI for protein and that lactating women add 1 I/4day,

The intake of protein recommended will only be effective in preventing signs of protein
deficiency if the needs for energy are met. If energy needs are not met, dietary protein will be
used ps a source pf energy, rather than going towards tissue growth and repair, Thus protein
qdeqvacy should be assessed in conjunction with energy adequacy. A child cpuld be living off
a diet which was primarily of meat and milk, but could show signs of protein deficiency
because of a low level of overall energy intake.


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