Asian Journal of Dietetics, 2024

Original
A Comparison of Physical Activity Among 10-year-old Children
Between Suburban Vietnam and Japan
Sumiko Kamoshita1, Phuong Mai Nguyen1*, Hitomi Takeichi2, Shigeru Yamamoto1
1

Nutrition and Food Culture Research Center, Jumonji University, Saitama, Japan
2
Faculty of Home Economics, Kobe Women’s University, Hyogo, Japan
ABSTRACT Background: The prevalence of overweight and obesity among Vietnamesechildren is increasing. Meanwhile, Japan is one of the few developed countries with the lowest
prevalence of childhood obesity in the world. The Japanese government has many policies toencourage children to be more active. Therefore, Japanese children had higher levels ofphysical activity compared to other countries. Purpose Evaluation and comparison of physicalactivity of Vietnamese and Japanese children. Methods: The 7-day and 3-day minute-byminute activity records were used to assess the physical activity of children aged 10 years old
in Hanoi suburban (Vietnam) and Tokyo suburban (Japan), respectively. Results: The physicalactivity level (PAL) was higher for Japanese children (1.54) than for Vietnamese children(1.42) (p<0.001). Time spent in moderate to vigorous physical activity in Japanese children
was about 2 times longer than for Vietnamese children (p<0.001). Conclusion: Japanesechildren had higher levels of physical activity than Vietnamese children. The Government ofVietnam needs to have appropriate policies to increase the level of physical activity ofVietnamese children in order to prevent and solve the problem of obesity.
Keywords: physical activity, children, suburban, Vietnam, JapanINTRODUCTION
In recent years, the increase in childhood obesity
has been remarkable in Vietnam. According to theresults of the National Nutrition Survey, Vietnam, inthe decade from 2010 to 2020, the prevalence ofoverweight and obesity among 5-19 year olds almost
doubled from 15.4% to 26.8% in urban areas and from
8.5% to 19% in rural areas (1). Meanwhile, theprevalence of overweight and obesity in Japanesechildren was about 11%, one of the lowest in thedeveloped countries (2). Therefore, many countries
have taken Japan as a model to compare and findsolutions to overcome overweight and obesity.
The low prevalence of obesity in Japan can be
explained through healthy lifestyle habits that theJapanese population have continued over time (3). The
Japan Sports Association published a guideline
entitled “Active Child 60 min” (4). The main target
were pre-school and primary school children (JapanSports Association 2010). Moreover, Japan has highrates (98.3%) of active transport to school amongchildren in public school compared with other similarincome countries (5). Japan has a highly established“walking to school practice” (5).
Meanwhile, in Vietnam, the sedentary lifestyle isincreasing in children (6). In addition, at present, mostof the studies focus on over intake, but not manystudies focus on assessing the physical activity ofchildren. Therefore, this study was conducted with theaim of assessing and comparing the physical activityof Vietnamese and Japanese children.

MATERIALS AND METHODS
Participants
A total of 134 children (73 boys and 61 girls) aged
10 years old at a public primary school in suburban
Hanoi participated in this study. The school was
selected by convenience sampling. All data werecollected in October of 2020. Informed consent was
obtained from the children, their guardians andteachers according to the Declaration of Helsinki, andthe study protocol was approved by the Biomedical
Research Ethics Committee of Hanoi Medical
University (no. 355/HMUIRB).
A total of 78 children (35 boys and 43 girls) aged
10 years old at an elementary school in Tokyo
suburban participated in this study. All data werecollected in November of 2022. Informed consent was
obtained from the children, their guardians andteachers according to the Declaration of Helsinki.
Physical activity assessments
The 7-day and 3-day minute-by-minute activity
records were used in suburban Hanoi and Tokyo,
respectively to assess the physical activity level. The
activity record form is designed based on the templatedeveloped by Koebnick et.al. The same recording
form was used in both the Vietnam and Japan surveys.
Numbers 1 to 24 contain general activities, but
activities that do not fit into these categories are
written in numbers 25 to 28. The "Other'' columns
prevent bias due to the recording form. Children were
instructed to record the activity by number shown inrecording form and mark the start and end times foreach activity (Fig 1). The recording method was
explained to teachers, children and their guardianswith an example of a completed physical activity
form. We asked teachers and guardians to help thechildren to complete the activity record. Whencollecting the activity record form, we interviewed
children to improve the accuracy of the activity record*To whom correspondence should be addressed:
nguyenmaiphuong2102@gmail.com

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Physical Activity of Vietnamese and Japanese Children
by adding and correcting the content regarding
omissions and unclear points.
Statistical analysis
The physical activity level (PAL) was calculated
based on the following formula:
PAL = ∑24h｛MET value of physical activity xtime (min)｝/1440 (minutes of 24 hours)
In which the MET value of physical activity wasreferenced from the compendium of physical activities
of Ainsworth et al (7).
The time spent in each physical acitivity intensity
each day was calculated using METs for eachparticipant: average minutes spent in sedentary andlight physical activity (METs< 3), moderate tovigorous physical activity (METs ≥3.0) (8), (9).
All statistical analyses were performed using
SPSS software (version 26; IBM Corporation,
Armonk, New York). The data were expressed as
mean±SD or %. The study analyses involved
comparisons between Tokyo suburban and Hanoi
suburban. Differences between groups were assessedusing independent t-tests and dependent t-tests forcontinuous data and chi-squared tests for categorical
data. P values less than 0.05 were defined as astatistical difference.

Fig 1. Physical activity recording form
RESULTS
Figure 2 shows the comparison of PAL between
Vietnamese and Japanese girls. In total, the PAL ofgirls in Tokyo suburban was significantly higher thanthose of Hanoi suburban at 1.45±0.10 and 1.40±0.12(p<0.05), respectively. The PAL of girls on weekdays
and weekends in Tokyo suburban was significantly
higher than those of Hanoi suburban were 1.45±0.11
vs 1.41±0.09 (p<0.05) and 1.46±0.18 vs 1.38 ±0.15(p<0.05), respectively. In overall, there was no
significant differences between PAL on weekdays andweekends in both Tokyo and Hanoi suburban(p>0.05).
Figure 3 shows the comparison of PAL between
Vietnamese and Japanese boys. In total, the PAL ofboys in Tokyo suburban was significantly higher thanthose of Hanoi suburban at 1.69±0.15 and 1.45±0.13,
respectively (p<0.001). The PAL of boys on weekdays
and weekends in Tokyo suburban was significantly
higher than those of Hanoi suburban were 1.67±0.14
vs 1.47±0.14 (p<0.001) and 1.74±0.29 vs 1.41±0.23(p<0.001), respectively. In overall, there was no
significant differences between PAL on weekdays andweekends in both Tokyo and Hanoi suburban(p>0.05).

Figure 4 shows the comparison of time spent on
moderate and vigorous physical activity between
Vietnamese and Japanese girls. In total, time spent formoderate to vigorous physical activity of girls inTokyo suburban was significantly higher than those of
Hanoi suburban at 153±59 and 85±37 min/d(p<0.001), respectively. Average time spent on
moderate to vigorous physical activity of girls on
weekdays and weekends in Tokyo suburban was
significantly higher than those of Hanoi suburban
were 145±62 vs 80±46 min/d (p<0.001) and 171±103
vs 95±62 min/d (p<0.001), respectively. In overall,there was no significant differences between averagetime spent on moderate to vigorous physical activity
on weekdays and weekends in both Tokyo and Hanoi
suburban (p>0.05).
Figure 5 shows the comparison of time spent on
moderate and vigorous physical activity between
Vietnamese and Japanese boys. In total, time spent formoderate to vigorous physical activity of boys inTokyo suburban was significantly higher than those of
Hanoi suburban at 175±93 and 97±43 min/d(p<0.001), respectively. Average time spent on
moderate to vigorous physical activity of boys on
weekdays and weekends in Tokyo suburban was26

Asian Journal of Dietetics, 2024
significantly higher than those of Hanoi suburban
were 157±74 vs 99±45 min/d (p<0.001) and 212±192
vs 92±67 min/d (p<0.001), respectively. In overall,there was no significant differences in average timespent on moderate to vigorous physical activity
between weekdays and weekends in both Hanoi andTokyo suburban (p>0.05)

Figure 2. Comparison of PAL between
Vietnamese (n=61) and Japanese girls (n=43)

Figure 3. Comparison of PAL between Vietnamese(n=73) and Japanese boys (n=35)

Figure 4. Comparison of time spent on moderate tovigorous physical activity between Vietnamese(n=61) and Japanese girls (n=43)

Figure 5. Comparison of time spent on moderate andvigorous physical activity between Vietnamese(n=73) and Japanese boys (n=35)

All values are mean±SD.
P-values were computed using an independent t-test between groups and a dependent t-test within group.
NS: non-significant differences and ***: significant differences at p<0.001.
PAL was calculated by ∑24h｛MET value of physical activity x time (min)｝/1440 min. It is the same as theaverage METs.
Table 1 compares some factors of physicalactivity in children aged 10 years old between Hanoi

suburban and Tokyo suburban. The sleeping time ofgirls and boys in Hanoi suburban was significantly

27

Physical Activity of Vietnamese and Japanese Children
longer than that in Tokyo suburban, with a differenceof 67 minutes and 39 minutes, respectively(p<0.001). Time spent for moderate to vigorous
physical activity of girls and boys in Tokyo suburban
was significantly higher than those of Hanoi
suburban at 153±59 vs 85±37 min/d (p<0.001) and

175±93 vs 97±43 min/d (p<0.001), respectively.
100% of children in the Tokyo suburban walked toschool while about 50% of children in the Hanoi
suburban walked or biked to school. The commutetime from school for children in Tokyo was about 3
times longer than that of Hanoi suburban (p<0.001).

Table 1 Comparison of some factors of physical activity in children aged 10 years old between Hanoi suburban(N=134) and Tokyo suburban (N=78) by gender
Girls
Boys
Hanoi
(n=61)
621±38Tokyo(n=43)
554±37p-value†Hanoi(n=73)
611±49Tokyo(n=35)
572±56p-value†Sleeping time (min/d)<0.001<0.001Moderate to vigorous
85±37
153±59<0.00197±43
175±93<0.001
physical activity (min/d)No. of children walking or
50.8
100<0.00152.1
100<0.001
biking to school (%)
Time of walking or biking
7±9
26±11
<0.0017±8
24±9<0.001to school (min/d)
Values are mean±SD and %.
†Independent t-test except Chi-squared test for walking or biking to school (%). Significant difference: p<0.05.
DISCUSSION
The purposes of the present study was to assessand compare the physical activiy in Vietnamese andJapanese children. The physical activity level inJapanese children was higher than that of Vietnames
children. The sleep time of Vietnamese children islonger than that of Japanese children. 100% ofJapanese children walked to school that was 2 times
higher than Vietnamese children. In particular, thetime spent on moderate and vigorous physicalactivities of Japanese children was about 2 times
higher than that of Vietnamese children.
The research period for this study was 7 days in
Vietnam and 3 days in Japan. In terms of physicalactivity assessment, previous research has shownthat with the minute-by-minute activity record
method, the 7-day study period gives reliable results(10). However, in Japan, the Japanese Ministry of
Education applied the physical activity record
method for three non-consecutive days (11).
Therefore, most of the studies on physical activity ofJapanese children were conducted over a nonconsecutive 3-day period and were found to bereliable. In other words, the difference in study
period does not affect the results of this study. The
two studies in Vietnam and Japan were all conductedaround October-November of the year and insuburban area to reduce spatial and temporal errors.
This allowed us to rule out differences in exercisethat might be caused by season.
Regarding physical activity, the present study
indicates that the level of physical activity of Tokyo
children is higher than that of Hanoi children of both
sexes, with a big difference especially among boys.
The sleep duration of Japanese children was about
554 min/d in girls and about 572 min/d in boys.
Sleeping time of girls and boys in Tokyo suburban
were significantly shorter than those of Hanoi
suburban at 67 and 39 min, respectively. Thisdifference may be due to the nap habits ofVietnamese. In Vietnam, after lunch, children haveabout 45-60 minutes to take a nap before theafternoon class starts. In the present study, 100% ofchildren in Tokyo suburban walked to school while
the percentage of children in Hanoi suburban walked
or cycled to school only about 50%. A crosssectional study in 2020 reported that 53% of school
children (aged 5-15 years) used active transport toand from school in Hanoi city (12). Promotion ofactive school travel (e.g., walking and cycling
to/from school) may be a way to improve children’s
health due to its association with levels of physicalactivity (13). In Japan, more than 90% of children
travel to school on foot, which may partly contributeto the relatively low prevalence of childhood obesityand being overweight (14). According to the 2018
Report Cards on Physical Activity for Children andYouth from 49 countries (also known as the Global
Matrix 3.0) (15), Japan was highly rated as “A-” (i.e.,
80–86% prevalence) for active transportation (16).
Previous research has shown that active school travel
was positively associated with neighborhood
physical and social environments, safety,
walkability, and neighborhood social interactions,and negatively associated with travel distance andcar ownership (17), (18). In particular, safety has
been identified as the core concept of school travel
policies (19), (20), most studies have focused on
traffic safety (21), (22). In the present study, theaverage time children walked to school about 30
minutes was an appropriate time because normally,
the walking distance to school ranges between 2 and4 kilometers for elementary school (3). In Vietnam,
to increase the rate of children walking to school, it
is necessary to improve the level of traffic safety as
well as social security.
The difference in physical activity levels
between children in Tokyo and Hanoi is mainly due
to the difference in time spent on moderate tovigorous physical activities. A survey conducted in
2021 in Japan revealed that almost 55% of girls andclose to 62% of boys aged between 4 and 11 years
28Asian Journal of Dietetics, 2024
participated in sports teams and clubs (23). Besides
sports clubs, schools often also offer clubs for
cultural activities, such as playing music instruments(23). In Vietnam, percentage of students who were
physically active for a total of at least 60 minutes per
day on all seven days during the past seven days was
13.6% (6). Additionally, for female students aged
10-11 years old showed that in 2012 only 11.9% of
the grade 5 students in Ho Chi Minh City
participated in active play after school (6). Timespent for moderate to vigorous physical activity ofgirls and boys in Tokyo suburban was significantly
higher than those of Hanoi suburban at 68 min/d and78 min/d, respectively. Consistently, the previous
studies indicated that more than half of the children
participated in organized sports for at least 60
minutes per day (4).
The evidence suggests that Vietnamese children
had low levels of physical activity. Physical activity
initiatives in Vietnamese children are largely
focused on enhancing physical education in schools(24). Public health policy initiatives should focus
more on community-based programs and promoting
physical activity environments for children outsideschool settings (6). As recommended by the WHO
ACTIVE toolkit, countries should focus on four
policy action areas: changing the population's
perception of the importance of physical activity;
providing safe and well-maintained facilities andgreen areas for physical activity; encouraging peopleof all age groups to engage in regular physicalactivity, and to build a strong leadership andgovernance system to support successful policy
implementation (6).
The present study has several limitations tonote. In terms of physical activity, the present study
was conducted in suburban areas of two big cities inVietnam and Japan at the same time of year.
However, the effects of the covid-19 pandemic may
affect children's physical activity in both countries.
A study to be conducted after the covid-19 pandemic
is needed. In addition, the cross-sectional designused in the present study could not determine
causality. Therefore, cohort studies should be
conducted among Vietnamese and Japanese children
in the future.

2)

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6)

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11)

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13)

ACKNOWLEDGMENTS
The authors are grateful to the all participants
for their cooperation and the staffs of Asian
Nutrition and Food Culture Research Center for theirassistance. We would like to thank Andrew Durkin,
Prof. Emeritus of Indiana University, for editing ourEnglish.

14)

15)

CONFLICT OF INTEREST
The authors has no conflicts of interest to
disclose.

1)

16)

REFERENCES
Ministries of Foreign Affairs of Japan.
Disasters and disaster prevention in Japan.
https://www.mofa.go.jp/policy/disaster/21st/2.
html#:~:text=Japan%20is%20particularly%20

17)

29

vulnerable%20to,of%20natural%20disasters%
20in%20Japan. Accessed June 22, 2023.
Baek Y, Owen AJ, Fisher J, Tran T, et al.
Lifetime impact of being underweight or
overweight/obese during childhood in
Vietnam. BMC Public Health 22(1):645. 2022.
Wang Y, Lobstein T. Worldwide trends inchildhood overweight and obesity. Int J Pediatr
Obes 1(1):11-25.2006.
Senauer B, Gemma M. Why Is the Obesity
Rate So Low in Japan and High in the U.S.?
Some Possible Economic Explanations.; 2006.
Tanaka S. Status of physical activity inJapanese adults and children. Ann Hum Biol
46(4):305-310. 2019.
Mori N, Armada F, Willcox DC. Walking to
School in Japan and Childhood Obesity
Prevention: New Lessons From an Old Policy.
Am J Public Health,102(11):2068. 2012.
Nguyen P, Nguyen DX, Khanh-Dao Le L, etal. Results from Viet Nam’s 2022 report cardon physical activity for children and youth. J
Exerc Sci Fit, 21(1):52-57. 2022.
Ainsworth B.E., Haskell W.L., Leon A.S., etal. Compendium of physical activities:classification of energy costs of humanphysical activities. Med Sci Sports Exerc
25(1): 71–80. 1993.
Haskell W.L., Lee I.M., Pate R.R., et al.
Physical Activity and Public Health: Updated
Recommendation for Adults from theAmerican College of Sports Medicine and theAmerican Heart Assocoation. Med Sci Sports
Exerc 39(8): 1423–1434. 2007.
Elliott S.A., Baxter K.A., et al. Accuracy of
Self-Reported Physical Activity Levels in
Obese Adolescents. J Nutrition andMetabolism. 2014.
Strath S.J., Kaminsky L.A., Ainsworth B.E., etal. Guide to the Assessment of Physical
Activity: Clinical and Research Applications.
Circulation, 128(20), 2259–2279. 2013.
Bouchard Three-Day Physical Activity
Record. Med Sci Sports Exerc 29(6):1924.1997.
Nguyen MH, Pojani D, Nguyen TC, et al. The
impact of Covid-19 on children’s active travelto school in Vietnam. J Transp Geogr,
96:103191. 2021.
Yoshinaga M, Miyazaki A, Aoki M, et al.
Promoting physical activity through walking totreat childhood obesity, mainly for mild tomoderate obesity. Pediatr Int, 62(8):976-984.
2020.
Ikeda N, Nishi N. First incidence andassociated factors of overweight and obesityfrom preschool to primary school: longitudinal
analysis of a national cohort in Japan. Int J
Obes (Lond), 43(4):751-760. 2019.
Coppinger T, Milton K, Murtagh E, et al.
Global Matrix 3.0 physical activity report cardfor children and youth: a comparison acrossEurope. Public Health, 187:150-156. 2020.
Tanaka C, Tanaka S, Inoue S, et al. Resultsfrom the Japan’s 2018 report card on physicalactivity for children and youth. J Exerc Sci Fit,
17(1):20-25. 2019.

Physical Activity of Vietnamese and Japanese Children18) Smith M, Ikeda E, Hawley G, et al. An
integrated conceptual model of environmental
needs for New Zealand children’s active travelto school. J. Transport Health, 16:100814.
2020.
19) Ikeda E, Hinckson E, Witten K, et al.
Associations of children’s active school travelwith perceptions of the physical environmentand characteristics of the social environment:
A systematic review. Health Place, 54:118131. 2018.
20) Aranda-Balboa MJ, Huertas-Delgado FJ,
Herrador-Colmenero M, et al. Parental barriers
to active transport to school: a systematic
review. Int J Public Health, 65(1):87-98. 2020.
21) Ikeda E, Mavoa S, Cavadino A, et al. Keeping
kids safe for active travel to school: A mixed
method examination of school policies andpractices and children’s school travel
behaviour. Travel Behav Soc, 21:57-68. 2020.
22) Rothman L, Buliung R, To T, et al.
Associations between parents ‫ ׳‬perception of

traffic danger, the built environment andwalking to school. J. Transport Health,2(3):327-335. 2015.
23) Giles-Corti B, Wood G, Pikora T, et al. Schoolsite and the potential to walk to school: theimpact of street connectivity and traffic
exposure in school neighborhoods. HealthPlace, 17(2):545-550. 2011.
24) Japan: children’s participation rate in sports
teams or clubs by gender 2021. Retrieved on
November
28,
2022
from
<https://www.statista.com/statistics/922647/japan-children-participation-ratesports-team-clubs-by-gender/>.
25) To QG, Wharton L, Gallegos D, et al. Schoolbased physical education: Physical activity andimplementation barriers in Vietnameseelementary schools. Eur Phy Educ Rev,
26(2):587-606. 2020.

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