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close this bookProtein-Energy Requirements of Developing Countries: Evaluation of New Data (UNU, 1981, 268 p.)
close this folderProtein requirements-children
close this folderProtein requirements of Filipino children 20 to 29 months old consuming local diets
View the document(introduction...)
View the documentObjective
View the documentExperimental details
View the documentSummary of main results
View the documentConclusions and comments

Summary of main results

1. Nitrogen Balance and Absorption Summaries of individual mean nitrogen and energy intakes, apparent nitrogen balances, apparent nitrogen digestibility, and weight changes for each experimental period are presented in table 3. Significant drops in nitrogen retention, nitrogen absorption, and biological values were observed with the lowest level of nitrogen intake 1120 mg/kg/ day), and in some cases with intakes of 160 mg/kg/day.

2. Protein Requirements Figure 1 shows the regression analysis of true nitrogen balance on nitrogen intake (Y = - 60.3 + 0.537 X, Se = 12.6, n = 38). The mean nitrogen requirement was calculated as 112 mg, or a PRm of 0.70 9 protein/kg/day. The safe level of intake for 97.5 per cent of the population was calculated as 161 mg nitrogen, or 1.00 9 protein/ kg/day.

3. Body Weight Table 4 indicates that three of the five undernourished children reached normal weights at the end of the study. They included the two children with intestinal parasites.

TABLE 3. Individual Nitrogen and Energy Intakes, Apparent Nitrogen Balance, Apparent Nitrogen Digestibility, Protein Biological Value, and Changes in Body Weight at Each Level of Dietary Protein Intake

Subject

Mean daily nitrogen Biological intake (mg/kg)

Mean daily energy intake

Mean daily nitrogen excretion

Balance, apparent
(mg/kg)

Absorption
apparent
(% of intake)

Retention, apparent (% of intake)

Biological value

Changes in body wt. (g/kg)

   

(kcal/kg)

(%PE*)

urine (mg/kg)

faeces (mg/kg)

         
R.A.

346

109

7.9

115

96

135

72.2

39.0

54.0

6.1

282

115

6.1

92

76

114

73.0

40.4

55.3

2.5

260

112

5.8

76

87

107

66.5

41.2

56.1

0.5

227

110

5.1

66

81

79

64.2

35.0

54.5

0.9

153

123

4.1

53

72

78

64.5

38.4

59.5

3.8

122

107

2.8

45

54

23

55.7

1 8.9

33.8

0

A.C.

358

113

7.9

113

119

126

66.8

35.2

52.7

9.9

321

118

6.8

94

99

128

66.2

39.9

57.7

- 1.2

275

121

5.7

86

88

100

67.9

36.5

53.8

5.9

244

127

4.8

66

91

87

62.7

35.6

56.9

1.1

209

129

4.0

56

63

90

69.9

43.1

61.6

1.8

133

108

3.1

45

61

27

54.1

20.3

37.5

2.4

M.C.

338

119

7.1

106

86

146

74.6

43.2

57.9

9.6

310

121

6.4

117

94

98

69.6

31.6

45.6

4.3

271

116

5.9

80

88

103

67.5

38.0

56.3

3.7

242

125

4.8

71

76

46

68.6

19.0

57.2

1.1

158

109

3.6

62

76

20

51.9

12.8

24.4

0

127

111

2.9

49

67

11

47.2

8.7

18.3

0.6

G.L.

277

98

7.0

130

79

68

71.5

24.6

34.3

2.9

234

100

5.9

100

69

65

70.5

27.8

39.4

2.4

204

100

5.1

79

62

63

69.6

30.9

44.4

0

170

100

4.3

57

64

49

62.4

28.8

46.2

- 1.0

125

99

3.2

53

55

17

56.0

13.6

24.3

1.9

J.M.

284

109

6.3

111

66

107

76.8

37.7

49.1

6.6

240**

113

5.3

92

82

66

65.8

27.5

41.8

0.5

200

100

5.0

57

51

62

74.5

31.0

41.6

- 1.7

154

100

3.9

59

48

47

68.8

30.5

44.3

1.8

120

99

3.0

65

48

7

60.0

5.8

9.7

-0.5

C.S.

263

107

6.4

99

78

86

70.3

32.7

76.5

- 2.3

255

108

5.9

88

75

92

70.6

36.1

51.1

2.2

190

107

4.4

68

76

46

60.0

24.2

40.4

1.1

171

109

3.9

61

79

31

53.8

18.1

33.7

2.7

112

110

2.5

47

60

5

46.4

4.5

9.6

- 0.8

R.A., Jr.

266

108

6.2

98

96

72

63.9

27.1

42.4

- 5.9

245

107

5.5

86

80

79

67.4

32.2

45.2

- 2.1

204

110

4.6

72

79

53

61.3

26.0

42.4

0.5

160

110

3.7

68

65

27

59.4

16.9

28.4

- 0.5

123

111

2.8

60

59

4

52.0

3.3

6.3

- 0.5

* Percentage of energy derived from dietary proteins.
** Child was given an antibiotic.



FIG. 1. Regression Analysis of "True" Nitrogen Balance on Nitrogen Intake (Pooled data, n = 38)

As table 3 shows, there was a trend towards increased rates of weight gain with protein-energy above 4 per cent. Appreciable weight gains were observed when nitrogen intakes were 270 mg/kg/day or higher.

4. Urinary Urea Nitrogen
Table 5 shows the results. There was a significant correlation between urinary urea nitrogen and nitrogen intake (r = 0.78, p < 0.001). The ratio of urinary urea nitrogen to urinary total nitrogen also correlated with nitrogen intake (r = 0.57, p < 0.001).