The utilization of dietary protein by Nigerian men

Abstract

I . The excretion of urinary and faecal nitrogen by young Nigerian men of a low income group was found to vary significantly between subjects, but was not significantly different in the same subject, when they were given a mixed diet composed of rice, vegetables and fish on two separate occasions. At the levels of energy and protein supplied by this diet the men gained or lost small amounts of weight, mean values indicating N equilibrium, the variation around the mean being high. 2.The correlation between the urinary and faecal N of these men was significantly negative at and below the level of N equilibrium, becoming positive 2-3 weeks after they had consumed the above diet supplemented by 400 g of lean beef per day, and had already established considerable rates of gain in body-weight and N retention. The diets were made isoenergetic by adding the beef at the expense of cassava flour and red palm oil.3. The physiological processes involved in the adaptation, by young Nigerian men of low income, to a highly efficient use of low-protein diets are discussed in relation to the biological value and true digestibility of those diets, and to the ' safe level of protein intake' and proteinenergy ratios proposed by FAO/WHO (1973.4. It is concluded that the protein requirements of apparently healthy men can only be established in the context of their ecological, socio-economic and nutritional backgrounds.

Human Amino Acid and Protein Requirements: Current Dilemmas and Uncertainties

“…1981) long-term studies maintained an adequate anabolic drive as well as N balance could only be assessed in terms of functional tests. These were not reported in the Nigerian studies, although the level of body protein at which they were apparently equilibrated was low, as indicated by their marked weight gains and positive N balance when given a large protein supplement (Nicol & Phillips, 19766). In the Berkeley studies (Durkin et al …”

The nature and significance of nutritional adaptation

“…Two examples that I know of in which protein was utilized at virtually 100% ef®ciency are our studies on children recovering from malnutrition (Chan & Waterlow, 1966), and the work of Nicol and Phillips (1976b) on Nigerian labourers, who utilized egg-protein added to a protein-free diet far more ef®ciently than subjects in California. I used to call these Nigerian subjects adapted whereas Nevin Scrimshaw used to maintain that they were depleted.…”

Adaptation to Restricted Intake of Protein and Energy

“…For example, Nicol and Phillips (14) showed that Nigerian adult males require about 30% less protein for maintenance than young North Americans. Payne (15) suggested that this probably reflects adaptation to a low habitual intake.…”