29. Long-term study on the adequacy of usual Thai weaning food for young children

Kraisid Tontisirin, Nissawan Ajmanwra, and Aree Valyasevi

Institute of Nutrition, c/d Ramathibodi Hospital. Mahidol University, Bangkok. Thailand

Summary of Short-term Study Phase 1 as Background Information

Nine children, aged 9 to 36 months, weighing 8.1 to 11.1 kg, and living in a metabolic unit, were given usual Thai weaning diets at three levels of energy intake varying from 87 to 118 kcal/kg/day. These diets consisted of rice, fish, and bananas. The protein intake was fixed at the "safe level," 1.7 g/kg/day, derived from rice and fish in a ratio of 70:30, and having an amino-acid score of 94.8 with assumed digestibility of 93 per cent.

Each level of energy intake was fed for seven days: the first four days for adaptation to a new intake level and the last three for balance studies. There was a four-day resting period between each treatment. Fat intake was kept constant throughout the study at about 10 per cent of energy intake. Vitamin and mineral supplements were given daily.

The adequacy of protein intake was evaluated by measuring N retention and weight gain. Other measurements included fat and energy absorption; blood constituents were also measured. A summary of the data in study phase 1 is shown in tables 1 and 2.

At the lowest level of energy intake, 87 kcal/kg/day, apparent N retention and weight gain were quite low, being 43.7 mg N/kg/day and 3.5 g/day respectively. At the two higher levels of energy intake (100 and 118 kcal/kg/day), apparent N retention was greater than 60 mg/kg/day and weight gain was about 20 g/day or more.

Biological value (BV) and net protein utilization (NPU) were clearly affected by the changes in energy intake. They decreased significantly with decreased energy intake. N absorption and digestibility, however, were not affected by changes in energy intake.

The results from this study suggest that at the "safe level" of protein intake, as recommended by FAO/WHO in 1973, the usual Thai weaning food provides adequate protein for the needs of young children if energy intake is supplied at 100 kcal/kg/day or higher.

TABLE 1 Summary of Study Phase 1 on the Effects of Varying Energy Intakes on the Adequacy of the Safe Level of Protein Intake in Young Children

	Energy intake (kcal/kg/day)
	87	100	118
Number of children	9	9	7
Age (months)	21.6 ± 2.8
Protein intake (g/kg/day)	1.7 ±0.01 a	1.7 ± 0.04	1.7 ±0.`05
Fat intake (% of energy)	11.2 ± 0.6	10 1 ± 0.2	10.1 ±0.5
Fat absorption (% of intake)	90.2 ± 1.0	91 4 ± 1.2	91.0 ±1.0
Energy absorption (% of intake)	8.5 ±0.4	6 7 ± 0.6	7.1 ±0.6
Weight gain (g/day)	3.5 ±6.9	20 3 ± 5.9	53.8 ±7.3
N balance (mg/kg/day)
N intake	271.2 ± 2.3	276. 4 ± 5.8	277.0 ±7.4
Urinary N	116.2 ± 6.9	100.5±6.8	80.2 ±4.8
Faecal N	111.3 ± 8.9	106.2 ± 10.9	121.6 ± 11.2
Apparent N balance	43.7 ± 6.8	69.6 ±7.8	75.7 ±7.6
Urinary creatinine (mg/day)	140.7 ± 11.6	1506 ±6.8	144 6 ± 8.1
Protein quality
N absorption (% of intake)	58.9 ± 3.4	61 7 ±3.6	56 5 ±3.5
Digestibility (%)	66.7 ± 3.4	69.4 ±3.7	64 1 ±3.6
BV (%)	61.3 ± 4.1	71.1 ±2.7	80 1 ±2.5
NPU (%)	40.5 ± 2.7	49.2 ±3.0	51 3 ±3.1

a Mean ± SE

TABLE 2. Summary of Blood Constituents in Study Phase 1

	Initial	Energy intake (kcal/kg/day)
		87	100	118
BUN (mg/dl)	8 7 ± 0 7 a	6 1 ± 0.6	5 4 ± 0 4	3 7 ± 0 5
Albumin (g/dl)	4 2 ± 0.06	4.0 ± 0.08	4 1 ± 0 09	3 9 ± 0 06
Total protein (g/dl)	6 8 ± 0 2	6 6 ± 0.1	6 8 ± 0 1	6.4 ± 0.1
AST (SF units)	355 ± 44	373 ± 43	375 ± 1 5	438 ± 20
ALT (SF units)	14 1 ± 1 3	13.8 ± 2.3	15 7 ± 1.1	22 9 ± 1 3

a Mean + SE

TABLE 3. Initial Characteristic of Six Young Male Children

Subject	Age (months)	Weight (kg)	Height (cm)	Weight for height (% of Thai standard)a
O.M.	12	8.7	67.8	100
A.B.	12	7.1	68.2	100
N.N.	8	7.3	68.1	90
D.S.	8	8.4	66.7	100
L.S.	9	7.9	67.2	90
K.P.	9	7.3	69.6	94
Mean ± SE	9.7 ± 0.8	7.8 ± 0.3	67.9 ± 0.4	95.7 ± 2.0

a From P Khanjanasthiti "The Anthropometric Nutritional Classification of the Infants and Preschool Children J Med Ass Thai., vol 60 Suppl 1 (1977)

Objective of Study Phase 2

The specific objective of this study was to determine whether a usual Thai weaning diet would provide adequate protein and energy for the needs of young children over a long-term period.

Experimental Design

Environment

The entire study was conducted in a metabolic ward of Ramathibodi Hospital, Mahidol University. The subjects were under close nursing and medical care and were also provided with adequate play facilities.

Subjects

Six normal, healthy, young male children aged 8-12 months were selected from an orphanage. They were studied after they had been rehabilitated for protein-energy malnutrition for eight weeks or longer and had reached normal weights for height. Their initial characteristics are shown in table 3. The means of age, weight and height were 9.7 months, 7.8 kg, and 67.9 cm, respectively. They were completely reexamined before the beginning of the study to ascertain that they were in good health.

TABLE 4. Proximate Analysis of Usual Thai Weaning Diet

Nutrients	per 100 g
Protein (g)	1.70
Fat (g)	0.19
CHO (g)	12.98
Energy (kcal)	69.37
Moisture (g)	85.07
Ash (g)	0.25

Diets

The diets given to the children were largely based on rice and fresh-water fish, supplying protein in a ratio of 70:30 by weight. Fifty grams each of green leafy vegetables and ripe banana were also given daily. Fat intake was provided at a level of 10 per cent of energy intake. Neither vitamin nor mineral supplements were given to the children during the study. Table 4 shows the data for proximate analysis of the diets.

In order to maintain precision in dietary components, diets were prepared in advance for each month of dietary testing. The body weights of the subjects were taken into account for readjustments of protein and energy food contents.

Protein and energy intake levels were 1.7 g/kg/day and 100 kcal/kg/day, respectively. The usual Thai weaning diet is fed in three meals per day. with drinks containing sugar once or twice a day.

Duration

The entire study lasted for 120 days, or four months.

Measurements Taken

Figure 1 shows the experimental design of the study. The entire study was divided into four periods, with each period lasting for 30 days.

1. Diet samples - for each period, a one-day diet sample analysed twice a month for N, energy (bomb calorimetry), and fat.

2. Fasting blood samples were taken initially and at the end of each month for analyses of complete blood count, total serum protein, albumin, and urea N.

FIG. 1 Experimental Design for Long-term Study of Six Infants Given Usual Thai Weaning Food.

TABLE 5. Protein, Fat and Energy Intake of Six Infants Given Usual Thai Weaning Food for Four Months

Period	Subject	Energy Intake (kcal/kg/day)	Protein Intake		Fat Intake
			(% energy)	(g/kg/day)	(% energy)	(g/day)
1	O.M.	98.8	7.2	1.8	9.3	8.7
	A.B.	94.9	7.2	1.8	10 8	8.2
	N.N.	96.9	7.2	1.8	10.0	8.1
	D.S.	103.5	6.8	1.7	11.7	10.7
	L.S.	96.3	7.2	1.8	8.7	7.6
	K.P.	104.9	7.2	1.8	10.9	8.9
	Mean ± SE	99.2 ± 1.7	7.1 ± 0.1	1.8 ± 0.02	10.2 ± 0.4	8.7 ± 0.4
2	O.M.	91.4	6.8	1.7	9.4	9.7
	A.B.	99.5	7.6	1.9	9.0	7.1
	N.N.	95.2	7.6	1.9	11.5	9.7
	D.S.	100.6	6.8	1.7	9 4	9.1
	L.S.	95.6	6.8	1.8	9.5	8.7
	K.P.	108.6	6.8	1.7	9.8	8.3
	Mean ± SE	98.5 ± 2.4	7.1 ± 0.6	1.8 ± 0.04	9.8 ± 0.4	8.8 ± 0.4
3	O.M.	87.6	6.0	1.5	8.8	9 3
	A.B.	95.7	7.6	1.9	9.6	7.8
	N.N.	94.0	7.2	1.8	10.5	8.2
	D.S.	-	-	-	-	-
	L.S.	94.7	6.8	1.7	10.0	9.3
	K.P.	98 7	6.8	1.7	10.9	9.4
	Mean ± SE	94.1 ± 1.8	6.8 ± 0.3	1.7 ± 0.1	10.0 ± 0.4	8.8 ± 0.3
4	O.M.	98.1	6.4	1.6	8.6	9.4
	A.B.	82.4	6.0	1.7	8.8	7.4
	N.N.	94.0	6.8	1.7	9.5	8.3
	D.S.	-	-	-	-	-
	L.S.	94.7	6.4	1.6	10.1	9.6
	K.P.	97.2	6.4	1.6	9.9	8.7
	Mean ± SE	93.2 ± 2.8	6.4 ± 0.1	1.6 ± 0.1	9.4 ± 0.3	8.7 ± 0.4

Statistical analysis:

Period 1 vs. 2	NS	NS	WS
Period 2 vs. 3	P < 0.025	P<0.05	NS
Period 3 vs. 4	NS	NS	NS
Period 1 vs. 4	NS	P < 0.05	NS

TABLE 6. N Balance in Six Infants Given Usual Thai Weaning Food for Four Months

Period	Subject Number	Energy intake (kcal/kg/day)	N balance (mg/kg/day)
			N intake	Urinary N	Faecal N	Apparent N balance
1	6	99.2±1.7	282.8± 7.5	92.3± 6.2	90.5±10.0	100.1± 8.4
2	6	98.5±2.4	287.3± 9.1	101.2± 6.8	101.6±5.6	84.5± 11.4
3	5	94.1±1.8	273.0±12.7	111.4±12.8	90.5±4.6	71.3±13.1
4	5	93.2±2.8	255.4± 4.3	123.1± 7.1	86.1 ± 3.2	46.1 ± 5.7

Statistical analysis.

Period 1 vs. 2	NS	NS	NS	NS	NS
Period 2 vs. 3	P < 0.025	P < 0 05	NS	P < 0 05	NS
Period 3 vs 4	NS	NS	NS	NS	NS
Period 1 vs 4	NS	P < 0.05	P < 0 05	NS	P < 0.025

3. 24-hour urine samples were collected during days 7, 14, 21, and 27 to 30 of each period for analyses of total N and creatinine (see fig. 1).

4. Three-day faecal collections were taken at the end of each period during days 27 to 30 of the month for analyses of N, energy, and fat.

5. Body weights were measured daily before breakfast, and other anthropometric measurements, including height, head, and left mid-arm circumference, and tricep skin-fold thickness, were measured every week.

Physical activities

The subjects were allowed normal activities, which included playing on the floor of the metabolic ward. Toys and mobile units were provided. Children were put on metabolic beds during the period of urine collection.

Main Results

continue