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close this bookProtein-Energy Requirements of Developing Countries: Evaluation of New Data (UNU, 1981, 268 p.)
close this folderResearch papers: Protein requirements-adults, standard protocols
close this folderCapacity of the Chilean mixed diet to meet the protein and energy requirements of young adult males
View the document(introduction...)
View the documentExperimental details
View the documentSummary of main results
View the documentConclusions
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Conclusions

1. The mean nitrogen requirements with egg and the mixed Chilean diets correspond to 97 and 125 mg N (or 0.61 and 0.78 9 proteins)/kg/day, respectively,

2. The current FAD/WHO safe level of egg protein intake (0.6 g/kg/day) was adequate for only three of eight men. The safe level of intake for our subjects is 0.8 to 1.1 9 egg protein/kg/day, depending on the approach used to estimate inter individual variability.

3. Faecal nitrogen did not vary at the three levels of protein intake, although it was

TABLE 6. Plasma Constituents for Subjects Consuming Two Levels of Egg Protein and a Chilean Mixed Diet 1

  Initial

Egg (g/kg)

Mixed diet (g/kg)

Diet effect 2 - way ANOVA

        F P
0.30 0.60 0.40 0.70 (4.33)  
Total protein, g/dl 7.5 0.4 7.6 0.4 7.6 + 0.3 6.9 0.4 7.1 0.5 4.7 <0.05
Albumin, g/dl 5.2 0.3 5.3 0.3 5.3 + 0.4 4.8 0.4 4.7 0.3 5.5 <0.05
Urea nitrogen, mg/dl 13.7 1.7 7.0 1.4 8.0 1.6 6.1 2.1 8.2 2.8 17.5 <0.001
SGOT,Karmen units/dl 18.710.1 14.05.6 16.2+5.2 23.9 12.7 18.1+7.0 1.5 n.S.
SGPT, Karmen units/dl 17.1 9.6 10.13.4 10.33.5 13.810.7 10.24.4 1.5 N.S.

1 Mean S. D.

4. The anthropometric indices suggest that our subjects are leaner than the normal standard, and hence a higher energy intake on a body-weight basis can be expected. There was a negative correlation (r = 0.89) between the weight-height (W/H) index and the energy intake required to maintain stable body weight. From this regression, the estimated energy intake for a subject with a W/H index of 100 per cent is 44.7 kcal/kg, which is similar to the energy requirements of healthy, normal Caucasian subjects. Our subjects consumed a mean of 49.5 kcal/kg. The minor changes observed in weight, body circumferences, and skin-fold measurements suggest that our subjects were close to equibrium and that their high energy intakes are accounted for by their body composition and activity pattern.

5. Based on the regression equations with the egg diet, the mean obligatory nitrogen losses were 69 mg N/kg/day, which are similar to those estimated from available data corrected by the 30 per cent factor for decreased efficiency of utilization within the maintenance range.

6. BUN decreased with both diets, suggesting a change in the urea pool. With the mixed diet there was also a decrease in serum protein and albumin.

7. It is necessary to re-evaluate dietary protein recommendations. Long-term evaluations with 0.8 or 1.0 9 protein/kg/day, respectively, of egg or a mixed diet of mainly vegetable origin should be undertaken.