Asia Pacific J Clin Nutr (1995) 4,2: 220-224

Use of food intake and body mass index (BMI) in the assessment of adult nutritional status in Viet Nam including a maternal-child analysis

Ha Huy Khoi, Tu Giay

National Institute of Nutrition, Hanoi, Viet Nam

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The authors have used food intake and Body Mass Index (BMI) to assess Vietnamese adult nutritional status. Chronic Energy Deficiency (CED) is prevalent in Vietnamese adults with an average percentage about 40%. The mean value of BMI in the 26-40 year old age group is 19.7 but it decreases thereafter except in urban areas. The change in the BMI curve distribution varies among adults living in rural, urban and mountainous areas. There seems to be a relationship between the BMI of mothers and the nutritional status of their children underthe age of 5. Some findings revealed a relationship between maternal BMI and birth weight and between CED and health status. The proposed cut-off point of Ferro-Luzzi-James in the classification of CED was applied to data from Vietnam.

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Introduction:

There are some common indices, such as Broca and Lorentz, used to assess the nutritional status of adults. The calculated values for these weight-stature indices differ although they are highly correlated. Comparison between available data is difficult when different indices are used. Recently, to assess the nutritional status of adults, WHO/ FAO has recommended the use of the Body Mass Index (BMI) [Weight (kg)/ height (m)²] calculated and classified as follows¹:

In a report by a Working Party of the International Dietary Energy Consultative Group², new criteria were proposed for classifying Chronic Energy Deficiency (CED) in adults, involving measuring BMI, energy intake (or expenditure) and basal metabolic rate (BMR).

Recently a simplified approach using BMI alone has been proposed to assess adult CED³. In this approach, a BMI greater than 18.5 is classified as normal, from 17-18.4 is grade I CED, from 16-16.9 is grade II CED and below 16.0 is grade III CED. In this paper, we present the use of BMI as an indicator of adult nutritional status within this population. The results were collected from various surveys and studies.

Prevalence of CED in Vietnam.

Study 1: During the period 1981-1985, the weights and heights of 12,800 rural adults were recorded in different age groups and ecological regions. The results of Study 1 are presented in Tables 1 and 2 and show that:

• BMI mean values decrease after 40 years in each gender
• CED is quite prevalent in Vietnam
• the average percentage of adults having BMI less than 18.5 is about 40%
• the highest percentage was shown in the oldest age group of both genders ( Figures 1 and 2 ).

• BMI	MEN	WOMEN
  Low	< 20.0	< 18.6
  Desirable range	20.1-25.0	18.7-23.8 1000
  Overweight	25.1-30.0	23.9-8.6
  Obese	> 30.0	> 28.6

Table 1. Mean ± SD value of BMI (kg/m2) of adults Age Group Males Females 18-25 19.2 ± 1.9 19.8 ± 1.9 26-40 19.7 ± 1.7 19.7 ± 1.8 41-60 19.0 ± 1.8 18.6 ± 2.0 > 60 18.2 ± 2.2 17.8 ± 2.2 Table 2. Classification of nutritional status (%) using BMI as indicator Age groups BMI groups < 16 16.0-16.9 17.0-18.4 Total < 18.5 18-25 Male 1.2 2.4 22.4 26.0   Female 2.7 5.3 20.5 28.5 26-40 Male 0.8 2.5 18.3 21.6   Female 0.4 0.8 16.6 17.8 41-60 Male 1.4 7.9 28.4 37.7   Female 5.0 7.7 29.7 42.4 >60 Male 5.8 12.6 32.6 51.0   Female 15.8 12.6 36.8 65.2

Figure 1 Frequency distribution of Body Mass Index (BMI) in women

Figure 2 Frequency distribution of BMI in males

 

Study 2: From 1987-1989 we carried out a general nutrition survey of a sample of 12,789 households in different regions of the country including Hanoi and Ho Chi Minh City. The survey findings of Study 2 consist of: measurement of household food composition during 3 consecutive days for household members and the recording of socioeconomic factors⁵.

The survey results (Tables 3 to 7 and Figures 3 and 4) show that the pattern of change in BMI is similar in rural and mountainous areas but is different in urban areas. In the first two groups, the BMI mean values were highest at the age of 25-29 years for males and 18-24 years for females; they were lower in the urban group during these ages. The urban BMI mean values increased up to the age group of 50-59 years and decreased thereafter. This fact may be due to differences in food intake, energy expen-diture and lifestyle of the populations in these regions.

Table 3. Food consumption (grammes per capita per day) (mean ± SD)

1000

Foodstuffs	Urban (n = 1655)	Rural (n = 9135)	Mountainous (n = 1634)
Rice-- cooked	421.3 ± 112.3	457.1 ± 133.9	498.0 ± 129.2
Other cereals	14.2 ± 30.2	3.7 ± 26.7	7.4 ± 33.6
Tubers	11.8 ± 33.2	47.5 ± 118.9	38.8 ± 119.9
Beans & Peas	2.4 ± 10.2	1.6 ± 10.1	4.0 ± 20.5
Tofu	16.5 ± 33.7	4.9 ± 18.8	8.7 ± 24.2
Nut & Sesame	4.2 ± 10.6	3.0 ± 13.0	9.4 ± 20.8
Veg. leaves	108.5 ± 77.3	145.2 ± 113.9	169.0 ± 106.3
Veg. tubers	39.4 ± 49.2	49.4 ± 87.3	68.5 ± 78.7
Fruits	10.2 ± 33.8	1.2 ± 13.1	0.2 ± 3.7
Sugar	1.8 ± 6.9	0.3 ± 2.8	0.1 ± 1.2
Sauces	22.3 ± 25.8	30.2 ± 31.7	23.5 ± 34.8
Oil & Fat	6.4 ± 9.8	2.6 ± 6.6	2.7 ± 8.3
Meats	49.3 ± 50.2	13.7 ± 31.1	28.5 ± 40.9
Eggs & milk	9.6 ± 18.6	1.4 ± 6.6	2.0 ± 11.2
Fish	62.2 ± 81.1	29.3 ± 40.8	8.1 ± 18.1
Other aquatics	7.8 ± 16.4	8.8 ± 21.1	1.8 ± 8.3

Table 4. Nutritive value of dietary intake (per capita per day) (mean ± SD)

1000

Nutients	Urban (n = 1655)	Rural (n = 9153)	Mountainous (n = 1634)
Protein (g) -Animal protein	62.5 ± 19.8 22.7 ± 14.6	53.9 ± 18.6 11.2 ± 12.4	57.7 ± 18.3 7.8 ± 9.9
Lipids (g) -Vegetable lipids	28.7 ± 17.5 7.0 ± 7.8	13.9 ± 12.4 6.6 ± 6.6	18.8 ± 15.5 10.3 ± 9.6
Carbohydrate (g)	336.2 ± 85.4	375.4 ± 102.2	411.1 ± 93.7
Energy (KCal)	1905.2 ± 485.2	1892.8 ± 524.4	2101.5 ± 498.2
Calcium (mg)	464.6 ± 266.7	553.0 ± 471.9	408.3 ± 216.6
P (mg)	789.0 ± 229.3	702.5 ± 223.2	758.8 ± 229.8
Fe (mg)	9.8 ± 2.8	9.5 ± 3.1	10.3 ± 3.5
Vitamin A (mg)	0.1 ± 0.4	0.0 ± 0.1	0.0 ± 0.1
Carotene (mg)	2.1 ± 1.9	2.8 ± 3.1	2.6 ± 2.7
Vitamin B1 (mg)	0.8 ± 0.3	0.7 ± 0.3	0.8 ± 0.3
Vitamin B2 (mg)	0.5 ± 0.3	0.3 ± 0.2	0.4 ± 0.2
Nicotinic Acid (mg)	10.7 ± 3.8	9.7 ± 3.5	11.4 ± 4.8
Vitamin C (mg)	48.7 ± 44.0	61.2 ± 59.4	73.7 ± 55.8

Table 5. Balanced characteristics of the dietary intake

Nutrients	Urban n = 1655	Rural n = 9153	Mountain n = 1634
Energy (Kcal)	1905.2 ± 485.2	1892.8 ± 524.4	2101.5 ± 498.2
Protein energy (%)	13.5%	11.7%	11.3%
Lipid energy (%)	14.0%	6.8%	8.3%
Carbohydrate energy (%)	72.3%	81.3%	80.2%
Animal Protein/ Total Protein (%)	36.3%	20.9%	13.6%
Veg Lipid/ Total Lipid (%)	24.4%	47.9%	54.8%
Ca/ P	0.59	0.79	0.54
B1 (mg)/ 1000 Kcal	0.49	0.37	0.43

Table 6. BMI of males by age group

Age group	For all	Urban	Rural	Mountainous
15-17	17.919 ± 2.811 n = 2236	17.402 ± 2.007 n = 394	17.962 ± 3.114 n = 1488	18.357 ± 2.05 n = 333
18-24	19.397 ± 1.943 n = 3006	18.755 ± 2.118 n = 483	19.435 ± 1.904 n = 1975	19.877 ± 1.722 n = 520
25-29	19.682 ± 1.791 n = 2322	19.271 ± 1.911 n = 239	19.678 ± 1.719 n = 1653	19.87 ± 1.943 n = 400
30-39	19.603 ± 1.914 n = 3213	19.539 ± 2.087 n = 363	19.623 ± 1.892 n = 2347	19.54 ± 1.91 n = 459
40-49	19.476 ± 2.698 n = 1908	19.683 ± 4.129 n = 515	19.385 ± 1.897 n = 1142	19.372 ± 1.947 n = 224
50-59	19.129 ± 2.022 n = 1989	19.739 ± 2.337 n = 368	19.004 ± 1.943 n = 1341	18.956 ± 1.771 n = 265
60-69	18.75 ± 3.063 n = 1338	18.992 ± 2.412 n = 154	18.774 ± 3.37 n = 949	18.448 ± 1.864 n = 226
>70	17.942 ± 2.277 n = 711	17.887 ± 2.422 n = 95	18.059 ± 2.154 n = 495	17.504 ± 2.594 n = 119

Table 7. BMI of females by age groups

Age group	For all	Urban	Rural	Mountainous
15-17	18.261 ± 2.263 n = 2303	17.623 ± 2.002 n = 461	18.328 ± 2.36 n = 1501	18.861 ± 1.942 n = 331
18-24	19.609 ± 1.987 n = 4312	18.726 ± 1.957 n = 605	19.724 ± 1.964 n = 3031	19.823 ± 1.903 n = 636
25-29	19.599 ± 1.888 n = 2856	19.023 ± 2.015 n = 337	19.675 ± 1.857 n = 2086	19.561 ± 1.811 n = 381
30-39	19.363 ± 1.98 n = 3921	19.446 ± 2.204 n = 611	19.395 ± 1.927 n = 2781	19.206 ± 1.909 n = 469
40-49	19.22 ± 2.069 n = 2320	19.503 ± 2.227 n = 590	19.164 ± 1.933 n = 1446	18.841 ± 2.329 n = 261
50-59	18.691 ± 2.165 n = 2271	19.988 ± 2.556 n = 278	18.585 ± 2.069 n = 1691	18.605 ± 2.234 n = 294
60-69	18.244 ± 2.266 n = 1591	18.975 ± 2.624 n = 199	18.164 ± 2.153 n = 1166	17.983 ± 2.375 n = 219
>70	17.695 ± 2.335 n = 920	18.314 ± 2.726 n = 142	17.605 ± 2.276 n = 639	17.412 ± 2.044 n = 134

Figure 3. BMI of males by age group

As shown in Tables 3, 4, and 5, there are not significant differences in total caloric intake but the percentage of lipid energy to total energy and animal protein to total protein is higher in urban populations than in the other groups. In general, rice is the main cereal of the diet, the intake of other cereals, tubers, beans and nuts rich in lipid is low. The consumption of animal food as meat, fish, eggs and fat is higher in urban areas than in rural and mountainous areas (Tables 3 and 4). It should be mentioned that the average height and weight of urban residents is generally higher than that of rural and mountainous areas.

Figure 4. BMI of females by age group

BMI index of mothers and nutritional status of children younger than 5 years. Data from Study 2 were analysed to establish the relationship between the BMI index of mothers and the nutritional status of their young children within different categories of BMI. There is a significant relationship between the two parameters (Table 8). Weight for age was used to assess nutritional status with the data from National Center for Health Statistics of United States (NCHS) as reference population6,9 and classified as the first degree when below -2 SD, the 2nd degree when below -3 SD and the 3rd degree when below -4 SD of NCHS value. The relationship between the BMI of women and the economic status of their families was not significant. The economic status of families was classified into 3 categories (low, middle, high) according to data relating to their main properties-- house and precious goods, because accurate incomes are difficult to collect. Effect of low BMI on health status In study 3, carried out on 1990, we followed the change in food i 1000 ntake and mothers’ weight gain during pregnancy, and recorded some biochemical indicators of nutritional status of the newborns including weight. The result of study 36 indicated that the average gain in weight of mothers during pregnancy in rural areas is 6.4kg and in Hanoi City 8.5kg. The study also revealed a significant relationship between the weight of the new born and the pre-pregnancy BMI values of the mothers (Table 9).

Table 8. Relation between BMI of mothersand nutritional status of children younger than 5 years Classification BMI Normal CED I CED II CED III Total Weight by age           Normal % 53.20 48.10 44.00 44.30 51.40 N 1162 324 77 35 1598 1st degree % 32.40 33.60 35.40 29.10 32.70 N 707 226 62 23 1018 2nd degree % 12.90 16.30 17.70 24.10 14.20 N 281 110 31 19 441 3rd degree % 1.60 1.90 2.90 2.50 1.70 N 34 13 5 2 54 Total % 70.20 21.60 5.60 2.50   N 2184 673 175 79 3111

Table 9. Relation between weight gained during pregnancy and birth weight for mothers grouped by pre-pregnancy BMI Weight gained during pregnancy Newborn weight (g) by mothers’ BMI levels P     < 18.5 > 18.5   < 8kg 2770 n = 2