Overweight, obesity, and associated factors among Vietnamese and Southeast Asian children and adolescents - Oxford Scholarship Jump to ContentJump to Main Navigation
Childhood Obesity PreventionInternational Research, Controversies and Interventions$

Jennifer A. O'Dea and Michael Eriksen

Print publication date: 2010

Print ISBN-13: 9780199572915

Published to Oxford Scholarship Online: January 2011

DOI: 10.1093/acprof:oso/9780199572915.001.0001

ContentsFRONT MATTER
Show Summary Details
Page of

PRINTED FROM OXFORD SCHOLARSHIP ONLINE (www.oxfordscholarship.com). (c) Copyright Oxford University Press, 2015. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a monograph in OSO for personal use (for details see http://www.oxfordscholarship.com/page/privacy-policy). Subscriber: null; date: 27 August 2016

Overweight, obesity, and associated factors among Vietnamese and Southeast Asian children and adolescents

Overweight, obesity, and associated factors among Vietnamese and Southeast Asian children and adolescents

Chapter:
(p.132) Chapter 11 Overweight, obesity, and associated factors among Vietnamese and Southeast Asian children and adolescents
Source:
Childhood Obesity Prevention
Author(s):

Nguyen Hoang H. Doan Trang

Tang K. Hong

Michael J. Dibley

Publisher:
Oxford University Press
DOI:10.1093/acprof:oso/9780199572915.003.0011

Abstract and Keywords

This chapter describes the prevalence and trends of overweight and obesity and associated factors among children and adolescents in Vietnam and Southeast Asia. In general there is very limited data available about child and adolescent obesity for this region. However, the results indicate a very rapid increase of overweight and obesity in school students, from pre-school to high school, especially in urban areas. In most studies, the prevalence of overweight among boys was greater than that among girls. This is a different pattern compared to child and adolescent obesity studies from industrialized countries, where the progressive increase in overweight and obesity in younger age groups was observed. Furthermore, while studies from western countries showed higher prevalence of overweight and obesity amongst children from households with low economic status, the findings from Southeast Asian countries revealed the reverse of this pattern, such as in Vietnam and Indonesia. The methods used to assess the prevalence of overweight and obesity varied among countries in this region, making cross country comparisons difficult. Studies in Southeast Asia have mentioned differences in adolescent overweight and obesity across gender and age groups, which might influence the likelihood of participating in physical activity and sport, and may differentially influence the benefits of physical activity in maintaining a healthy weight status. School location was also a notable risk factor of overweight and obesity in children in many studies of this region. Children from private schools had higher odds of overweight/obesity than those from public schools (Philippines, Indonesia); higher odds of overweight in students studying at schools in wealthy urban districts were found in Vietnam.

Keywords:   overweight, obesity, children, adolescents, epidemiology, economic status, Vietnam, Asia

Chapter summary

The purpose of this chapter is to describe the prevalence and trends of overweight and obesity and associated factors among children and adolescents in Vietnam and Southeast Asia. In general there are very limited data available about child and adolescent obesity for this region. However, the results indicate a very rapid increase of overweight and obesity in school students, from pre-school to high school, especially in urban areas. The prevalence of overweight and obese adolescents in Ho Chi Minh City, Vietnam, in 2004 was 11.7% and 2.1%, respectively, whereas in the cross-sectional study in 2002, the prevalence of overweight and obese adolescents was only 5.0% and 0.6% respectively. Two separate studies, in 1990 and 1997, carried out among adolescent boys studying in the same four schools in Malaysia, reported an increase in prevalence of obesity from 1% in 1990 to 6% in 1997. In Thailand, the authors found that overweight prevalence in males increased from 12.4% in 1992 to 21.0% in 1997, whereas that of females went down from 15.2% to 12.6%. For the Philippines, there was a generally decreasing trend of overweight with age from 8 to 10 years among public schoolchildren, but not among private schoolchildren. Similar findings have been reported from Indonesia in a cross-sectional comparison between surveys in 1999 and 2004 showing a significant increase in overweight of Indonesian adolescents (from 5.3% to 8.6%) but no significant change in obesity (from 2.7% to 3.7%).

In most studies, the prevalence of overweight among boys was greater than that among girls. This is a different pattern compared to studies of child and adolescent obesity from industrialized countries. In these studies, the progressive increase in overweight and obesity in younger age groups was observed. Furthermore, whereas studies from Western countries showed higher prevalence of overweight and obesity amongst children from households with low economic status, the findings from Southeast Asian countries, such as Vietnam and Indonesia, revealed the reverse of this pattern.

The methods used to assess the prevalence of overweight and obesity are different from different countries of this area. Whereas the study in Vietnam used IOTF cut-offs, studies in Malaysia, Indonesia, and Philippines applied weight-for-height z-score (overweight is defined when WH Z-score 〉 2 SD) or percentile (overweight is defined when BMI ≥ 85th percentile, and obesity was defined when BMI ≥ 95th percentile), making cross country comparisons difficult.

(p.133) Studies in Southeast Asia have mentioned differences in adolescent overweight and obesity across gender and age groups, which might influence the likelihood of participating in physical activity and sport and might differentially influence the benefits of physical activity on the maintenance of a healthy weight status. School location was also a notable risk factor of overweight and obesity in children in many studies of this region. Children from private schools had higher odds of overweight/obesity than those from public schools (Philippines, Indonesia) or the higher odds of overweight in students studying at schools in wealthy urban districts was found in Vietnam.

Introduction

Studies of children and adolescents indicate that the prevalence of overweight and obesity is particularly high in North America, Great Britain, South-West Europe, and the Pacific countries including Australia and New Zealand (Magarey et al., 2001; Tremblay et al., 2002; Hohepa et al., 2004; Janssen et al., 2005). Although the prevalence of overweight and obesity in children in these countries far exceeds the levels reported for Asia, the situation, in Vietnam and other countries in Southeast Asia, is changing rapidly in response to the economic and social changes taking place in these countries (Mo-suwan & Geater, 1996; Ismail et al., 2002). Increasing levels of household wealth and urbanization are leading to a nutrition transition with children and their families having higher dietary intakes of energy and fat and lower intake of fruit and vegetables. Concurrently the levels of physical activity for children are falling with more passive forms of transportation, and reduced opportunities for active play because of crowded environments and the high expectations of parents and society for academic achievement ahead of all else.

This chapter aims to answer the following research questions. How rapidly is child and adolescent obesity emerging as a public health problem in this region? What are the key factors associated overweight and obesity in children and adolescents in these countries? It addresses these research questions by reviewing recently published literature to describe the prevalence and trends of overweight and obesity and associated factors among children and adolescents in Vietnam and Southeast Asia.

Methods

Literature search

We searched the EMBASE®, CINAHL®, and MEDLINE® databases for published studies on child or adolescent overweight or obesity in Vietnam and other Southeast Asian countries including Thailand, Singapore, Malaysia, Indonesia, the Philippines, Laos, and Cambodia. In the search we used the queries ‘child/adolescent AND overweight/obesity’ and limited the citations to studies from the specified countries. Similar searches were conducted using BMI to replace overweight or obesity. In total we identified 26 studies that assessed the prevalence of overweight or obesity in child or adolescent populations in Southeast Asian countries.

Anthropometric methods

The International Obesity Task Force (IOTF) has proposed cut-off values of BMI to classify overweight and obesity in children according to age and gender (Cole et al., 2000), which have been used worldwide (Janssen et al., 2005). However, in the Southeast Asian region, different studies have applied a variety of criteria to define overweight and obesity in children. Whereas a study in Vietnam used IOTF cut-offs (Hong et al., 2007), studies in Malaysia, Indonesia, and Philippines applied weight-for-height Z-score (overweight was defined when weight-for-height Z-score 〉 2 SD) (p.134) (Tee et al., 2002; Julia et al., 2008) or percentiles (overweight was defined as BMI ≥ 85th percentile, and obesity as BMI ≥ 95th percentile) (Florentino et al., 2002; Julia et al., 2008).

It was not possible to restrict the articles examined in this review to those that used IOTF criteria because of the limited number of surveys assessing overweight and obesity in children and adolescents from Southeast Asia. Thus the estimates of prevalence of overweight and obesity from different countries are based on different reference data to calculate the anthropometric indices, different cut-off values, and even different indicators (Bronner, 1996), making cross-country comparisons difficult.

We have also included new results from two surveys the authors conducted in Ho Chi Minh City, Vietnam, in 2002 and 2004. The details of the survey methods used can be found in the original publications describing these studies (Tang et al., 2007; Hong, 2005).

Prevalence and trends in child overweight and obesity in Vietnam and Southeast Asia

In Vietnam most reports of childhood and adolescent overweight and obesity are from Ho Chi Minh City, the largest and most developed city in the country. The surveys from this city indicate that recently there has been a very rapid increase in the prevalence of overweight and obesity in secondary high school students. Two recent epidemiological surveys conducted in 2002 (Tang et al., 2007) and 2004 (Hong, 2005), among representative samples from junior high school students aged from 11 to 16 years living in the city, reveal a rapid decrease in the prevalence of underweight (defined as BMI Z-score 〈 −2 SD using CDC growth reference) and a similarly rapid increase in overweight and obesity. As seen in Table 11.1, the prevalence of underweight approximately halved between 2002 and 2004, whereas the prevalence of overweight and obesity more than doubled in this population.

These surveys have revealed the important differences in the prevalence of overweight and obesity by gender with boys having a higher prevalence and greater rate of increase than girls. Across the population in 2002 the prevalence of overweight and obesity in boys was 9.0% (95% CI: 5.7%, 12.3%) but only 5.9% (95% CI: 3.6%, 8.2%) in girls (Hong et al., 2007). By 2004 the prevalence of overweight and obesity in boys had more than doubled to 19.2% (95% CI: 15.7%, 22.7%), whereas for girls the rate increased to only 8.2% (95% CI: 6.6, 9.9) (Hong, 2005).

In these studies a score based on an inventory of household assets was used to assess the level of household wealth and this score was divided into five equal categories with the lowest quintile representing the poorest households and the highest quintile the wealthiest households (Hong, 2005).

Table 11.1 Prevalence of underweight, overweight, and obesity among Ho Chi Minh city adolescents aged 11 to 16 years

BMI status

Survey 2002

Survey 2004

N = 1003

N = 2678

Percentage (%)

95% CI

Percentage (%)

95% CI

Underweight1

13.1

(10.9, 15.5)

6.6

(5.1, 8.1)

Overweight2

5.0

(3.7, 6.3)

11.7

(10.1, 13.3)

Obesity2

0.6

(0.2, 1.0)

2.1

(1.5, 2.6)

1Defined as BMI Z-score 〈 −2 SD using CDC growth reference.

2Defined using IOTF cut-offs.

(p.135)
                      Overweight, obesity, and associated factors among Vietnamese and Southeast Asian children and adolescents

Fig. 11.1 Trends in overweight (using IOTF cut offs) by household wealth index and year of survey among adolescents in Ho Chi Minh City.

The changes in the prevalence of overweight and obesity from 2002 to 2004, broken down by gender, and the wealthiest and the poorest households, are illustrated in Fig. 11.1.

This figure highlights the large differences in the prevalence of overweight and obesity by household wealth. The adolescents from the wealthiest households were significantly more overweight and obese than those from the poorest households. For both genders combined in 2002 the prevalence of overweight and obesity in children from the poorest quintile of households was 4.5% (95% CI: 0.2%, 7.2%), whereas it was more than double in the wealthiest quintile of households at 11% (95% CI: 5.7%, 16.3%). This gap increased further by 2004 with the prevalence of overweight and obesity in children from the poorest quintile of households at 6% (95% CI: 3.4%, 8.5%) compared to 19.5% (95% CI: 15.3%, 23.6%) in the wealthiest quintile of households. Furthermore, the figure reveals that the rate of increase in overweight and obesity is greatest in the wealthiest adolescents especially amongst the boys.

Evidence of the obesity epidemic in Ho Chi Minh City can also be found in preschool aged children. In the 2005, a cross-sectional survey of a representative sample of 670 pre-school aged children in urban areas of the city reported a remarkably high prevalence of overweight (20.5%) and obesity (16.3%) using IOTF criteria (Thi Thu Dieu et al., 2007). Boys were heavier and taller than girls in each age group. These findings confirm the cohort effect, in which progressively younger age groups in Ho Chi Minh City have more obesity, presumably because of their greater exposure to the developing obesogenic environment. The same authors have investigated the trends in overweight and obesity in pre-school children in urban areas of Ho Chi Minh City, Vietnam, from 2002 to 2005. The trends were consistent with the findings for adolescents: The prevalence of overweight and obesity almost doubled from 2002 to 2005 (21.4% and 36.8%, respectively). The proportion of boys classified as obese in 2005 (22.5%) was three times that in 2002 (6.9%). However, the increase was more evident in less wealthy districts than in wealthy districts (Dieu et al., 2009). This later finding suggests that the urban population in Ho Chi Minh City has become wealthy enough for children even from the lower socio-economic groups to experience excess weight gain. Also alarming about these findings is the extent of overweight and obesity in this young population with reported levels as high, or higher than, in most industrialized countries.

In other Southeast Asian countries the information about the prevalence of overweight and obesity in children and adolescents and the changes over time is limited. Results similar to the (p.136) findings from Vietnam have been reported in a limited number of studies from other countries in Southeast Asia. Malaysia is at the crossroads of a nutrition and lifestyle transition, and Malaysians are increasingly consuming diets that are high in fat and calories and generally leading more sedentary lifestyles (Tee, 1999). In Malaysia, a study on 5995 primary school children in the year 1996 reported that the prevalence of overweight (weight-for-height Z score 〉 2 SD) was 7.7%. In this population, the prevalence of overweight among boys (9.5%) was about 1.9 times greater than that among girls (5.1%) (Tee et al., 2002). Two separate studies, in 1990 and 1997, carried out among adolescent boys studying in the same four schools in Klang Valley, reported an increase in prevalence of obesity from 1% in 1990 to 6% in 1997 (Ismail & Vickneswary, 1999; Ismail & Zulkifli, 1996).

A review of research on overweight and obesity in Thailand also reported a trend to increasing overweight and obesity in Thai children. In a longitudinal study, 2252 primary and secondary schoolchildren of Hat Yai, a municipality in southern Thailand, were recruited in 1992 and after a follow-up for 5 years, the authors found that prevalence of overweight in males (using the 85th percentile of the US First National Health and Nutritional Examination Survey reference for age and sex as a cut-off point) increased from 12.4% in 1992 to 21% in 1997, whereas that of females went down from 15.2% to 12.6%. At the end of the fifth year, 11.8% of the children remained overweight whereas 4.5% had become overweight (Mo-suwan et al., 2000). Data from the national health survey in 1997 and 2001 revealed a substantial rise in prevalence of obesity from 5.8% in 1997 to 7.9% in 2001 for 2–5-year-olds (Mo-suwan, 2008) from 5.8% in 1997 to 6.7% in 2001 for the 6–12-year-olds. The prevalence was higher in the urban children (Mo-suwan, 2006). Using the same adiposity indices, overweight and obesity in urban school-aged children increased from 15.1% in 2001 (Mo-suwan, 2006) to 16.7% in 2005 (Mo-suwan, 2008). A study in 2003 amongst the primary school children (7-9 years old) in Northeast Thailand (urban Khon Kaen) showed the prevalence of childhood obesity to be 10.8%, whereas in Pattani province a survey in 2004 on 9393 public high school students (13–18 years old) revealed 9% overweight/obesity (6.8% overweight/2.2% obesity).

In Singapore, Ho indicated that there was a steady increase of prevalence from 1976 to 1980, with a sharp increase in prevalence in 1983. It was found that obesity was significantly more prevalent in males than in females (Ho, 1985).

For the Philippines, the prevalence of overweight among private schoolchildren (24.9%) was almost four times higher than that among public schoolchildren (5.8%): there was a generally decreasing trend of overweight with age from 8 to 10 years among public schoolchildren, but not among private schoolchildren (Florentino et al., 2002).

Similarly, in Indonesia, in a study of urban schoolchildren aged 8 to 10 years in Bogor and Jakarta, there were more overweight children in the private schools than in the public schools. The prevalence of overweight (BMI 〉 85th percentile) ranged from 15.3% (girls) to 17.8% (boys) (Soekirman et al., 2002). In another study, the cross-sectional comparison between the 1999 and 2004 surveys showed a significant increase in overweight of Indonesian adolescents (from 5.3% to 8.6%) but no significant increase in obesity (from 2.7% to 3.7%) (Julia et al., 2008). After 5.1 (± 0.6) years, the prevalence of overweight and obesity increased from 4.2% and 1.9% in childhood to 8.8% and 3.2%. A cross-sectional study conducted in school-aged pre-pubertal children in two adjacent areas in Central Java (Yogyakarta as an urban area, and Gunung Kidul as a rural area) reported a prevalence of overweight of 2.3%. In the study both rural and poor urban children were significantly less likely to be overweight than were non-poor urban children (Julia et al., 2004).

The findings from many studies of child and adolescent overweight/obesity in Southeast Asia show strikingly different patterns of overweight and obesity compared to studies of child and (p.137) adolescent obesity from industrialized countries. Firstly, most studies from Western countries have found a higher prevalence of obesity with girls than with boys, the reverse of what is reported in Southeast Asia. A comparison of studies among 13 European countries and the US reported that the prevalence of overweight (BMI ≥ 95th percentile) was highest in the US with higher rates in girls than in boys (Lissau et al., 2004). A cross-sectional study in England also found more girls than boys were overweight (Saxena et al., 2004). The studies in Ho Chi Minh City found that overweight and obesity was more prevalent in males than in females (Hong, 2005; Thi Thu Dieu et al., 2007). These gender differences could be explained in terms of a societal male gender preference or different social expectations about body size and proportions between girls and boys in Asian countries. Reports from Malaysia reveal an increasing prevalence of obesity in adolescents, especially males from urban areas who were more obese than females (Noor, 2002). In Indonesia, the obesity rate was also found to be higher in boys than in girls (Collins et al., 2008; Julia et al., 2008; Soekirman et al., 2002).

Secondly, the progressive increase in overweight and obesity in younger age groups has not been reported in developed countries, although a similar pattern has been reported in other countries undergoing a rapid nutrition transition (Li et al., 2005; Mo-suwan et al., 1993). In studies from Vietnam, BMI was also related to age (Tang et al., 2007). In Malaysia, the prevalence of overweight decreased with increasing age (Tee et al., 2002). In Vietnam the distribution of age and gender across categories of wealth, pubertal stage, school location, and residence were examined showing that these variables were distributed equally across wealth, pubertal stage, school location, and residence categories (Hong, 2005).

Thirdly, most studies from Western countries have reported higher prevalence of overweight and obesity amongst children from households with low economic status. A cross-sectional study from eastern France conducted in 2001 found the prevalence of overweight and obesity was higher in low economic zones and was inversely associated with family income tax (a measure of income), for example, in boys 23.6% from the lowest-income group compared to 15.3% from the highest-income group (Klein-Platat et al., 2003). Similar findings have been reported for adolescents in the US from the Third National Health and Nutrition Examination Survey (NHANES) 1988–1994, where the prevalence of overweight and obesity (defined as BMI 〉 85th percentile of CDC 2000 Growth Reference) was 32.7% in low-income families and 19.0% in high-income families (Wang, 2001). In Vietnam, the authors found increased odds of childhood overweight/obesity in wealthier households (Hong, 2005; Thi Thu Dieu et al., 2007), similar to that reported in other developing countries undergoing a nutrition transition such as Indonesia (Julia et al., 2004). However many studies from other Southeast Asian countries have not examined this phenomenon.

Overall, these findings highlight that the patterns of overweight and obesity found in Southeast Asia are very different from those in industrialized countries and indicate that interventions developed in the West may not be suitable for Southeast Asian countries.

Factors associated with childhood overweight and obesity in Southeast Asia

Weight gain is the result of a positive energy balance (consuming more energy than is expended). Energy expenditure, as assessed through levels of physical activity, declines in children as they reach adolescence, particularly in adolescent girls. Many studies have mentioned differences in adolescent overweight and obesity across gender and age groups (i.e. there was an increased risk of overweight and obesity in male adolescents and age had a positive association with BMI) (Collins et al., 2008; De Onis et al., 2001; Jackson et al., 2002; Li et al., 2008; Tang et al., 2007). (p.138) Both studies conducted in pre-school aged children and adolescents in Ho Chi Minh City, Vietnam, found higher odds of being obese in boys than in girls (Hong, 2005; Thi Thu Dieu et al., 2007). Furthermore, the prevalence of overweight/obesity was significantly higher in the younger age groups (Tang et al., 2007). Gender and age might influence the likelihood of participating in physical activity and sports, and might differentially influence the benefits of physical activity on the maintenance of a healthy weight status (Davison & Birch, 2001). Boys are usually more physically active than girls (Sallis et al., 2000); however, adolescent girls tend to be more self-aware of their appearance and more likely to be concerned about their weight than boys.

The dietary practices of younger children are much more dependent on parental control, and parents are more likely to encourage their younger children to eat more. This encouragement has been observed as a factor positively associated with children’s energy intake and also associated with the time children spend eating, which in turn, is positively associated with their degree of fatness. In studies from Malaysia, Indonesia, and Vietnam, the obesity rate was also found to be higher in boys than in girls (Collins et al., 2008; Julia et al., 2008; Tang et al., 2007; Hong, 2005; Tee et al., 2002; Thi Thu Dieu et al., 2007). However, this gender difference was not evident in Philippine children (Florentino et al., 2002), and the reverse was found in Thailand (Aekplakorn & Mo-suwan, 2009; Mo-suwan et al., 2000).

Among countries in Southeast Asia, the prevalence of childhood overweight and obesity has increased concomitantly with the extent of the country’s socioeconomic transition. The prevalence is generally higher in urban areas than in the rural areas, and in higher socioeconomic groups of the population. Unlike developed countries, where the highest prevalence of overweight has usually been found among poorer families, in studies of Southeast Asia, we found an increased risk of childhood overweight/obesity in wealthier households, similar to that reported in other developing countries undergoing a nutrition transition (Collins et al., 2008; Florentino et al., 2002; Julia et al., 2008; Mo-suwan & Geater, 1996; Tee et al., 2002; Tang et al., 2007; Thi Thu Dieu et al., 2007). Even in Indonesia, the growth of high socioeconomic class preschool children from Jakarta was at least equal to that of the American reference population (Droomers et al., 1995).

School location was a notable risk factor of overweight and obesity in children in many studies of this region. In Vietnam, most of the schools with a high academic standard are located in the wealthy urban districts, and as a result these schools tend to attract students from higher socioeconomic families (Hong, 2005). Hence the higher risk of overweight in students studying at schools in wealthy urban districts is expected. In some schools because academic achievement is the main focus of the curriculum the requirement for physical activity has declined. In addition, the play yards for students in schools located in wealthy urban districts were significantly narrower that those in schools located in less wealthy urban districts. Similar findings have been reported from studies in the Philippines and Indonesia, where children from private schools had higher odds of overweight/obesity than those from public schools (Florentino et al., 2002; Soekirman et al., 2002).

In contrast to findings from developed countries, where the prevalence of overweight was inversely associated with family income, results from studies of the Southeast Asian region found an increased risk of overweight/obesity in adolescents from families of higher economic status. Parents from wealthier households with adequate resources for food, televisions (TVs), computers and other ‘labour saving’ household devices are likely to have encouraged diets and lifestyles for their children that promote obesity. Higher rates of overweight were found in schools located in wealthy urban districts (Hong, 2005). The most desirable schools in Ho Chi Minh City are located in these districts and there is intense competition to gain admission. Children from higher socioeconomic status families and children whose parents have higher levels of education are more likely to gain admission to these schools. Furthermore, schools in wealthy districts usually have less space for playgrounds and may place less emphasis on physical activity in the curriculum.

(p.139) The findings from the Southeast Asia region showed a markedly higher prevalence of overweight and obesity in children from urban areas when compared to rural areas (Hong, 2005; Julia et al., 2004; Tee et al., 2002), in contrast to studies from the West where the urban–rural differences in overweight and obesity in children are much smaller and the prevalence of overweight and obesity is higher in the rural than in the urban areas (Moreno et al., 2001; Oner et al., 2004). In contrast to the situation in developed countries, most countries in Southeast Asia face a double burden of both under-nutrition and over-nutrition, with both problems exerting considerable stress on the health system.

Parental characteristics were explored in the present study, including the parent’s education, and family economic status. In contrast to findings from French and US studies (Gordon-Larsen et al., 2003; Klein-Platat et al., 2003), where the percentage of overweight and obese children was higher if their parents (both or either father or mother) were of lower level of education, the two cross-sectional studies in Ho Chi Minh City revealed the reverse pattern where the percentage of overweight and obese children was higher if their parents had higher levels of education (Hong, 2005; Thi Thu Dieu et al., 2007). This is understandable in the context of Vietnam where recent periods of economic difficulties and insufficiency of food lead parents to perceive fat children as healthy and well nourished. Well-educated adults have found it easy to find jobs as the economic reforms began in the mid-1980s and they can easily provide their children with a comfortable life including dietary and physical activity lifestyles that place the children in these families at higher risk of overweight. In developed countries, this phenomenon might be explained by attitudes about dietary recommendations and the value of slimness may be linked more to educational level rather than income level. However, in developing countries highly educated parents might have good jobs and want to provide their children with a ‘modern’ life with plenty of modern recreational facilities such as TVs and computers. The parents often give pocket money to their children, which may be used to buy snacks. For these reasons, overweight and obesity is more common in wealthier families and in children with more highly educated parents.

The parents’ perception of well-being and healthiness may also help to explain the relationship between parent’s overweight status with overweight and obesity in children. Some studies have noted that mothers with higher weight status are more likely to give their children snacks of low nutrient density (Davison & Birch, 2001) and children of overweight mothers are also more likely to consume more fat as a proportion of food intake in comparison to children of normal weight mothers (Nguyen et al., 1996). A genetic familial tendency to overweight and obesity may also contribute to the association between overweight parents and overweight children. Studies in Vietnam found a higher risk of being overweight when the parents were overweight (Hong, 2005; Thi Thu Dieu et al., 2007). Mothers are usually more involved with child care related to growth, e.g. in food preparation and choice. In these studies, children and adolescents with overweight mothers had nearly 1.5–4 times higher odds of overweight and obesity compared to those with normal weight mothers. The odds of overweight in children whose father was overweight also increased 1.59–3 times. However, the risk was highest for children when both parents were overweight. These findings also found in Thailand (Mo-suwan & Geater, 1996).

As mentioned earlier, the reason for overweight and obesity in children and adolescents involves a complex set of factors and multiple contexts that interact with each other (Davison & Birch, 2001). Family environments are likely to influence the risk the child would become overweight. The results of studies in Southeast Asia revealed a negative association between availability of fruit at home with the odds of overweight and obesity. Children’s eating habits are influenced by their family or parents’ dietary practices (Gibson et al., 1998). Increasing their food availability and larger portion sizes promotes overeating (Hill & Peters, 1998). In Asia, it is common for the mother to be the one who is mainly responsible for food preparation at home; hence the mother’s (p.140) nutritional knowledge and concern for disease prevention will be strongly associated with the children’s food consumption. Thus, if fruits were usually stored in the fridge at home children would be more likely to eat them rather than consuming other low nutrient foods. The findings from studies of this region, once again, confirm the role of the home environment in the development of childhood obesity.

Many studies (Giammattei et al., 2003; Janssen et al., 2004) have reported a positive association of obesity with soft drink consumption. Giammattei even reported that ‘drinking three or more soft drinks per day was associated with a 46% increase in chance of being overweight’. (Giammattei et al., 2003). In the study of Vietnamese adolescents, frequent consumption of soft drinks increased the odds of overweight more than two times if compared to not consuming these beverages. Infrequent consumption of soft drinks still increased the odds of overweight and obesity by approximately 1.5 times. These findings contrast with the results for frequency of consumption of fruit and vegetables, where high frequency of consumption of vegetables halved the odds of overweight and obesity compared to low or no consumption of vegetables, and similarly high frequency of consumption of fruit reduced the odds of overweight and obesity by one-fifth. This impact was higher when children frequently consumed both (fruits and vegetables). These findings imply that the role of diet in overweight and obesity in adolescents is complex and needs further study.

The amount of leisure time, especially time spent watching TV, playing computer games and videogames has been considered as a key factor for overweight. In the study on Vietnamese adolescents time watching TV during the week had a strong association with overweight/obesity in adolescents: children who spent 4 hours or longer per week day watching TV were four times more likely to be overweight than those who spent only 1 hour or less per day watching TV. The odds were also higher with those who spent 2 to 3 hours per week day watching TV. Several researchers have noted that watching TV can decrease the amount of time spent performing physical activity and can also be associated with increased food consumption either during viewing or as a result of food advertisements. However, in a study of children from Yogyakarta (Collins et al., 2008), time spent on the computer, watching TV, or on play station, and snacking while watching TV or frequency of fast food consumption were not found to be significantly independently related to obesity in the multivariate analysis. Similar findings were found in Malaysian female adolescents (Wan et al., 2004).

The level of physical activity as measured by energy expenditure of the urban adolescents in Vietnam was the same as that reported for normal weight female adolescents in Malaysia (Wan et al., 2004). The length of time the adolescents in Ho Chi Minh City spent watching television and playing with computer or video games was lower on average than what was reported in Malaysia. This may be because Ho Chi Minh City adolescents spend much more time after class studying (approximately 135 minutes per day) (Hong, 2005). This finding highlights the level of the schoolwork burden of high school students in Vietnam and this sedentary behaviour is likely to be an important contributor to overweight and obesity in this population.

Conclusions

Many Southeast Asian countries currently confront a nutrition transition with the double burden of underweight and overweight in adolescents. The problem of overweight and obesity is greater in males than in females, in younger age groups, in wealthy urban districts, and in children from high economic status families. Appropriate public health policies are needed to deal with both problems and long-term follow-up of these subjects should be undertaken to have a better understanding of the factors associated with obesity and the potential for prevention for overweight and obesity in this population of adolescents.

(p.141) References

Bibliography references:

Aekplakorn, W. & Mo-suwan, L. (2009) Prevalence of obesity in Thailand. Obesity Reviews 10, 589–592.

Bronner, Y.L. (1996) Nutritional status outcomes for children: ethnic, cultural, and environmental contexts. Journal of American Dietitics Association 96, 891–903.

Cole, T.J., Bellizzi, M.C., & Flegal, K.M. (2000) Establishing a standard definition for child overweight and obesity worldwide: international survey. BMJ 320, 1240–1243.

Collins, A.E., Pakiz, B., & Rock, C.L. (2008) Factors associated with obesity in Indonesian adolescents. International Journal of Pediatric Obesity 3, 58–64.

Davison, K.K. & Birch, L.L. (2001) Childhood overweight: a contextual model and recommendations for future research. Obesity Reviews 2, 159–171.

De Onis, M., Dasgupta, P., Saha, S., Sengupta, D., & Blossner, M. (2001) The National Center for Health Statistics reference and the growth of Indian adolescent boys. American Journal of Clinical Nutrition 74, 248–253.

Dieu, H.T., Dibley, M.J., Sibbritt, D.W., & Hanh, T.T. (2009) Trends in overweight and obesity in pre-school children in urban areas of Ho Chi Minh City, Vietnam, from 2002 to 2005. Public Health Nutrition 12, 702–709.

Droomers, M., Gross, R., Schultink, W., & Sastroamidjojo, S. (1995) High socioeconomic class preschool children from Jakarta, Indonesia are taller and heavier than NCHS reference population. European Journal of Clinical Nutrition 49, 740–744.

Florentino, R.F., Villavieja, G.M., & Lana, R.D. (2002) Regional study of nutritional status of urban primary schoolchildren. 1. Manila, Philippines. Food and Nutrition Bulletin 23, 24–30.

Giammattei, J., Blix, G., Marshak, H.H., Wollitzer, A.O., & Pettitt, D.J. (2003) Television watching and soft drink consumption: associations with obesity in 11- to 13-year-old schoolchildren. Archives of Pediatrics and Adolescent Medicine 157, 882–886.

Gibson, E.L., Wardle, J., & Watts, C.J. (1998) Fruit and vegetable consumption, nutritional knowledge and beliefs in mothers and children. Appetite 31, 205–228.

Gordon-Larsen, P., Adair, L.S., & Popkin, B.M. (2003) The relationship of ethnicity, socioeconomic factors, and overweight in US adolescents. Obesity Research 11, 121–129.

Hill, J.O. & Peters, J.C. (1998) Environmental contributions to the obesity epidemic. Science 280, 1371–1374.

Ho, T.F. (1985) Eleventh Haridas memorial lecture. Childhood obesity in Singapore primary school children: epidemiological review and anthropometric evaluation. Journal of Singapore Paediatric Society 27(Suppl 1), 5–40.

Hohepa, M., Schofield, G., & Kolt, G. (2004) Adolescent obesity and physical inactivity. New Zealand Medical Journal 117, U1210.

Hong, K.T. (2005) Diet, physical activity, environments and their relationship to the emergence of adolescent overweight and obesity in Ho Chi Minh City, Vietnam. University of Newcastle: Faculty of Health.

Hong, T.K., Dibley, M.J., Sibbritt, D., Binh, P.N., Trang, N.H., & Hanh, T.T. (2007) Overweight and obesity are rapidly emerging among adolescents in Ho Chi Minh City, Vietnam, 2002–2004. International Journal of Pediatric Obesity 2, 194–201.

Ismail, M.N., & Vickneswary, E.N. (1999) Prevalence of obesity in Malaysia: Data from three ethnic populations. Inoue & Zimmet (eds.) The Asia - Pacific Perspective: Redefining Obesity and its Treatment. WHO (WRRO)/IASO/10TF: Health Communication Australia.

Ismail, M.N. & Zulkifli, M. (1996) A study on obesity among male adolescents. National Conference on ‘Adolescent: Challenges of the 21st Century’. Kuala Lumpur.

Ismail, M.N., Chee, S.S., Nawawi, H., Yusoff, K., Lim, T.O., & James, W.P. (2002) Obesity in Malaysia. Obesity Reviews 3, 203–208.

Jackson, M., Samms-Vaughan, M., & Ashley, D. (2002) Nutritional status of 11–12-year-old Jamaican children: coexistence of under- and overnutrition in early adolescence. Public Health Nutrition 5, 281–288.

(p.142) Jackson, R.T., Rashed, M., & Saad-Eldin, R. (2003) Rural urban differences in weight, body image, and dieting behavior among adolescent Egyptian schoolgirls. International Journal of Food Sciences and Nutrition 54, 1–11.

Janssen, I., Katzmarzyk, P.T., Boyce, W.F., King, M.A., & Pickett, W. (2004) Overweight and obesity in Canadian adolescents and their associations with dietary habits and physical activity patterns. Journal of Adolescent Health 35, 360–367.

Janssen, I., Katzmarzyk, P.T., Boyce, W.F., et al. (2005) Comparison of overweight and obesity prevalence in school-aged youth from 34 countries and their relationships with physical activity and dietary patterns. Obesity Reviews 6, 123–132.

Julia, M., van Weissenbruch, M.M., de Waal, H.A., & Surjono, A. (2004) Influence of socioeconomic status on the prevalence of stunted growth and obesity in prepubertal Indonesian children. Food and Nutrition Bulletin 25, 354–360.

Julia, M., van Weissenbruch, M.M., Prawirohartono, E.P., Surjono, A., & Delemarre-van de Waal, H.A. (2008) Tracking for underweight, overweight and obesity from childhood to adolescence: a 5-year follow-up study in urban Indonesian children. Hormone Research 69, 301–306.

Klein-Platat, C., Wagner, A., Haan, M.C., Arveiler, D., Schlienger, J.L., & Simon, C. (2003) Prevalence and sociodemographic determinants of overweight in young French adolescents. Diabetes/Metabolism Research and Reviews 19, 153–158.

Li, M. (2005) The prevalence of overweight/obesity in school-aged adolescents in Xi’an City, China. University of Newcastle: Faculty of Health.

Li, M., Dibley, M.J., Sibbritt, D., & Yan, H. (2008) Factors associated with adolescents' overweight and obesity at community, school and household levels in Xi'an City, China: results of hierarchical analysis. European Journal of Clinical Nutrition 62, 635–643.

Lissau, I., Overpeck, M.D., Ruan, W.J., Due, P., Holstein, B.E., & Hediger, M.L. (2004) Body mass index and overweight in adolescents in 13 European countries, Israel, and the United States. Archives of Pediatrics and Adolescent Medicine 158, 27–33.

Magarey, A.M., Daniels, L.A., & Boulton, T.J. (2001) Prevalence of overweight and obesity in Australian children and adolescents: reassessment of 1985 and 1995 data against new standard international definitions. Medical Journal of Australia 174, 561–564.

Mo-suwan, L. (2006) Obesity: magnitude of problem in Thailand.

Mo-suwan, L. (2008) Childhood obesity: an overview. Siriraj Medical Journal 60, 37–40.

Mo-suwan, L. & Geater, A.F. (1996) Risk factors for childhood obesity in a transitional society in Thailand. International Journal of Obesity 20, 697–703.

Mo-suwan, L., Junjana, C., & Puetpaiboon, A. (1993) Increasing obesity in school children in a transitional society and the effect of the weight control program. Southeast Asian Journal of Tropical Medicine and Public Health 24, 590–594.

Mo-suwan, L., Tongkumchum, P., & Puetpaiboon, A. (2000) Determinants of overweight tracking from childhood to adolescence: a 5 y follow-up study of Hat Yai schoolchildren. International Journal of Obesity 2, 1642–1647.

Moreno, L.A., Sarria, A., Fleta, J., Rodriguez, G., Gonzalez, J.M.P., & Bueno, M. (2001) Sociodemographic factors and trends on overweight prevalence in children and adolescents in Aragon (Spain) from 1985 to 1995. Journal of Clinical Epidemiology 54, 921–927.

Nguyen, V.T., Larson, D.E., Johnson, R.K., & Goran, M.I. (1996) Fat intake and adiposity in children of lean and obese parents. American Journal of Clinical Nutrition 63, 507–513.

Noor, M.I. (2002) The nutrition and health transition in Malaysia. Public Health and Nutrition 5, 191–195.

Oner, N., Vatansever, U., Sari, A., et al. (2004) Prevalence of underweight, overweight and obesity in Turkish adolescents. Swiss Medical Weekly 134, 529–533.

Sallis, J.F., Prochaska, J.J., & Taylor, W.C. (2000) A review of correlates of physical activity of children and adolescents. Medicine and Science in Sports and Exercise 32, 963–975.

(p.143) Saxena, S., Ambler, G., Cole, T.J., & Majeed, A. (2004) Ethnic group differences in overweight and obese children and young people in England: cross sectional survey. Archives of Disease in Childhood 89, 30–36.

Soekirman, Hardinsyah, Jus'at, I., & Jahari, A.B. (2002) Regional study of nutritional status of urban primary schoolchildren. 2. West Jakarta and Bogor, Indonesia. Food and Nutrition Bulletin 23, 31–40.

Tang, H.K., Dibley, M.J., Sibbritt, D., & Tran, H.M. (2007) Gender and socio-economic differences in BMI of secondary high school students in Ho Chi Minh city. Asia Pacific Journal of Clinical Nutrition 16, 74–83.

Tee, E.S. (1999) Nutrition of Malaysians: where are we heading? Malaysian Journal of Nutrition 5, 87–109.

Tee, E.S., Khor, S.C., Ooi, H.E., Young, S.I., Zakiyah, O., & Zulkafli, H. (2002) Regional study of nutritional status of urban primary schoolchildren. 3. Kuala Lumpur, Malaysia. Food and Nutrition Bulletin 23, 41–47.

Thi Thu Dieu, H., Dibley, M.J., Sibbritt, D., & Thi Minh Hanh, T. (2007) Prevalence of overweight and obesity in preschool children and associated socio-demographic factors in Ho Chi Minh City, Vietnam. doi:10.1080/17477160601103922. International Journal of Pediatric Obesity 2, 40–50.

Tremblay, M.S., Katzmarzyk, P.T., & Willms, J.D. (2002) Temporal trends in overweight and obesity in Canada, 1981–1996. International Journal of Obesity 26, 538–543.

Wan, P.L., Kandiah, M., & Taib, M.N.M. (2004) Body image perception, dietary practices and phyical activity of overweight and normal weight Malaysian female adolescents. Malaysian Journal of Nutrition 10, 131–147.

Wang, Y. (2001) Cross-national comparison of childhood obesity: the epidemic and the relationship between obesity and socioeconomic status. International Journal of Epidemiology 30, 1129–1136.