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close this bookProtein-Energy Requirements of Developing Countries: Evaluation of New Data (UNU, 1981, 268 p.)
close this folderObligatory nitrogen losses-adults
close this folderObligatory nitrogen losses of adult Thai males
View the document(introduction...)
View the documentObjective
View the documentExperimental details
View the documentSummary of main result
View the documentConclusions and comments

Experimental details

1. Subjects
Four male adult Thais 21 to 25 years old. Their body weights were 45 to 67.5 kg, and their heights were 164.5 to 169 cm. They were healthy and well-nourished, based on medical history, physical examination, urinalysis, stool examination, chest x-ray, and a routine complete blood count.

2. Study Environment
The entire study was conducted at the clinical research ward (a metabolic unit) in

Ramathibodi Hospital. The climatic characteristics were those of tropical countries.

3. Physical Activity
The subjects were allowed to continue their usual activities but were not allowed to participate in competitive, active sports.

4. Duration of the Study
The study of obligatory nitrogen losses was carried out over a 14-day period.

TABLE 1. Composition of the Protein-Free Diet

Ingredients g/day
Mung bean starch 100.4
Mung bean noodles 100.0
Sugar 1 08.6
Margarine 48.0
Oil 30.0
Onion leaf 30.0
Wax gourd 27.0
Salt 5.1
Lemon juice 2.4
Soy sauce 2.0
Garlic 2.0
Carbonated beverage variable

5. Diets
The composition of the protein-free meal is shown in table 1. The subjects were given four meals per day at 7.30 a.m., 12 noon, 5.00 p.m., and 9.30 p.m. Daily energy intakes were constant, at about 45 kcal/kg/day. Fat provided approximately 30 per cent of the daily energy intake. Multivitamin and mineral tablets were given twice each day. Water was offered ad libitum but the volume was recorded daily.

6. Indicators and Measurements

  1. Total nitrogen in urine and faeces was measured by a calorimetric semi-automated procedure (Munro and Fleck, Mammalian Protein Metabolism, vol. 3 [1969]). Nitrogen balance was calculated from the last five and ten days of urinary and faecal nitrogen losses, respectively.
  2. Basal metabolic rate (BMR) was measured at seven-day intervals with a respirometer (closed circuit).
  3. Body weight was recorded daily.
  4. Serum concentrations of total protein, albumin, urea nitrogen, and some amino acids and amino transferase activities were measured at seven-day intervals.

TABLE 2. Obligatory Nitrogen Losses in Four Adult Thai Males

Subject U F S Total
M.P. 38.6 15.1 5 58.7
V.D. 32.5 12.4 5 49 9
S. R. 33.4 12.4 5 50.9
S.S. 35.0 10.6 5 50.6
Mean S.D. 34.9 2.7 12.6 1.9 5 10 52.5 4.2

U = urinary nitrogen losses, average from the last 5 days of 14-day dietary period.
F = faecal nitrogen losses, average from the last 10 days.
S = skin and other minor route nitrogen losses, taken from FAD/WHO.