Animal food sources are generally high in protein, so that
there is a clear relationship between protein intake and the
proportion of animal foods, especially meat, in the diet. As
shown in Table 1, the overall protein : energy (P : E) value of
the national food supply falls from 12·1 % energy in the
USA to 8 % in a Sub-Saharan African country like Sierra
Leone as the animal protein intake falls from 74 g/d to
6·9 g/d. In the UK the P : E value falls from 14·2 % energy in
omnivores to 12·7 % in the small number of vegetarians
(non-meat eaters) identified in the UK food intake survey
(Jackson & Margetts, 1993). Thus, protein intakes of
vegetarians are likely to be closer to the reference nutrient
intake (RNI; Department of Health, 1991) and approximately 20–30 % of this small sample were below the RNI.