Dietary Intake, Physical Activity and Energy Expenditure of Malaysian Adolescents
Dietary Intake, Physical Activity and Energy Expenditure of Malaysian Adolescents
significantly in time spent for low, medium            In Malaysia, the National Health and Morbidity         Norimah A K, PhD
                                                  Survey 2 (1996) reported that the prevalence               Associate Professor
and high intensity activities. Macronutrient
intakes differed significantly only among the      of being overweight and obese among adults is              Correspondence to:
                                                                                                             Dr Zalilah Mohd Shariff
girls where the OW group had the highest          20.7% and 5.8%, respectively(6). The prevalence of         Tel: (60) 3 8946 8551
intakes compared to UW and NW groups              overweight adults (body mass index [BMI] >25.0)            Fax: (60) 3 8942 6769
                                                                                                             Email: zalilah@
(p-value is less than 0.05). All study groups     in Malaysia appears to be higher than the levels           medic.upm.edu.my
                                                                                Singapore Med J 2006; 47(6) : 492
reported in other Asian countries, such as Thailand,           Technology and Environment. For this study, multi-
China and Japan(7). However, this health problem is            stage random sampling was utilised in the selection
not restricted only to the Malaysian adults. Among             of 14 secondary schools. Other inclusion criteria
the adolescents, the prevalence of overweight and              for the schools were: co-educational, multiracial in
obesity from independent studies ranges from 5%                composition, non-religious and non-residential.
to 26%, depending on the methods used to define                     All Secondary 1 and 2 male and female students
overweight and obesity, age, ethnicity, gender and             (n=6,555) in the age range of 11-15 years old were
locality(8-11).                                                included in the screening process where they were
    Reilly et al(12) showed that obesity in children           measured for their weight and height. BMI was
and adolescents is associated with both short-term             calculated for each respondent for the purpose of
and long-term consequences, although the latter                categorisation into underweight, overweight and
may be of a greater health concern. Short-term                 normal weight groups. These respondents were
consequences of obesity in children include low self-          then randomly sampled to obtain a total of 2,050
esteem, behavioural problems, clinical conditions              respondents for the assessment of body image. From
such as asthma, systemic inflammation and type 1                this sample, another sub-sample of 618 respondents
diabetes mellitus, and cardiovascular risk factors.            (317 female and 301 male adolescents) was randomly
Long-term consequences of obesity in childhood                 selected to complete additional measurements such
and adolescence may include adverse social and                 as three-day food and physical activity records.
economic outcomes (e.g. income, educational                    The study protocol and ethics were approved by the
achievement) and increased cardiovascular risks and            Malaysian Ministry of Education. Permissions to
premature mortality in adulthood.                              conduct the study were also obtained from the state
    The aetiology of obesity involves a complex                education departments and participating schools. The
interaction of various factors, such as genetics,              respondents were informed of the study and their
physical activity, diet, social, environment and               participation was voluntary. Those who participated
health. The roles of diet and physical activity in             were required to sign consent forms prior to the
body weight gain and body fat accumulation among               inception of the study.
adolescents have remained equivocal. While several                 The weight and height of the respondents
studies have reported on the positive associations             were measured with a TANITA digital scale and
between adiposity in children and adolescents                  a SECA body metre to the nearest 0.1 kg and 0.1
and energy intake, consumptions of high fat                    cm, respectively. Two measurements were taken for
foods and high sugar beverages and physical                    both weight and height, and the average of the two
inactivity(13-16), others have found no relationship(17-19).   values were used in the analyses. For measurement
The relationship between physical fitness and                   accuracy, the respondents were asked to remove their
adiposity has also been researched in line with the            shoes and empty their pockets, and the instruments
idea that overweight children had reduced physical             were calibrated daily. BMI was calculated based
fitness due to increased physical inactivity(20-22).            on the weight and height measurements and the
    Presently, published research on the relationship          categorisation of BMI levels were done according to
between adiposity with diet and physical activity              the age and gender-specific BMI for adolescents(23).
among Malaysian adolescents is limited. Hence, the             Thus, the BMI categories of UW, NW and OW
purpose of this study was to report on the energy              corresponded to <5th percentile, 5th - 85th percentile
and macronutrient intakes, and energy expenditure,             and ≥85th percentile, respectively.
among male and female adolescents according to                     For dietary intake, a self-administered three-
the various BMI levels, namely underweight (UW),               day food record (consecutive two weekdays and
normal weight (NW) and at risk of overweight                   a weekend) were obtained from the respondents.
(OW).                                                          Respondents were asked to record their consumption
                                                               of all foods and beverages, including snacks, and
METHODS                                                        to provide detailed descriptions of the foods and
This cross-sectional study was conducted as part               beverages, which included brand names and methods
of a multi-centre research project on “The study of            of food preparation. Food portions were estimated by
the relationship between dietary habits, physical              the respondents using standard household measuring
activity and nutritional status with body image                cups and spoons, matchbox (for meat, fish and bean
among adolescents” with financial support from                  curd), ruler (for fruit slices) and counts (for eggs,
the Intensification of Research in Priority Areas               biscuits, bread slices and fruits). Prior to that, the
(IRPA) grant of the Malaysian Ministry of Science,             researchers explained the food record form and the
                                                                                         Singapore Med J 2006; 47(6) : 493
food-measuring tools, and demonstrated the use of                   the dietary intake analysis. Dietary quality was
these instruments to the respondents. All dietary                   reported for macronutrient intakes (carbohydrate,
records were checked by researchers for accuracy                    fat and protein) as mean intakes in grammes and
and completeness. Further clarifications were sought                 percentages of energy.
from the respondents in cases where the food records                    As the data were parametric, one-way ANOVA
were incomplete or filled incorrectly. Calculation of                and chi-square analyses were conducted to assess the
energy and macronutrient intakes was done for each                  relationship between the BMI categories according
day, and the average of the three daysʼ calculation                 to gender and demographical, socioeconomic and
was taken in the final statistical analyses.                         physical measurements. The interaction between
    The respondents were also asked to record their                 ethnicity (Malay, Chinese and Indian) and household
physical activities simultaneously with their food                  income was tested with a two-way ANOVA; however,
records. This three-day activity record method                      no interaction effect was observed (F=0.65, p=0.63).
has been shown to be suitable for the estimation                    Finally, analysis of covariance (ANCOVA) was
of energy expenditure in children(24) and had been                  utilised to determine the mean differences in the
previously used among Malaysian adolescents(25).                    outcome variables among UW, NW and OW subjects
The activities including the body postures (sitting,                with statistical control of household income and
standing, walking and squatting) were recorded                      ethnicity. These covariates were included individually
every five minutes. There were a total of 42 recorded                and combined in the ANCOVA; however, the mean
activities and based on their characteristics and the               scores for all outcome variables from ANCOVA with
circumstances of their performance, these activities                individual covariate did not differ much from the
were then grouped into nine categories according                    mean scores when both covariates were included in
to energy cost or physical activity ratio (PAR) as                  ANCOVA. All statistical analyses were conducted
recommended by Torun(26). Thus, light, moderate and                 using Statistical Package for Social Sciences (SPSS)
high intensity activities were defined as activities                 version 11.5 (Chicago, IL, USA).
with PAR of 1-1.9, 2-2.9 and >3.0, respectively.
The sum of the duration (in minutes) of activities                  RESULTS
in each category was calculated and included in the                 Based on the screening sample (n=6,555), the
energy expenditure calculation(27). The calculation                 proportion of UW, NW and OW male and female
for the adolescentsʼ basal metabolic rate (BMR) in                  adolescents are presented in Table I. The prevalence
kcal/day, was based on a validated gender-specific                   of UW and OW was higher among male (14.8% and
BMR equation for Malaysian adolescents(25). Energy                  19.7%) than female (7.9% and 16.7%) adolescents.
expended for physical activity was calculated as the                The mean and range of BMI for male and female
difference between total energy expenditure and                     adolescents were 19.26 + 4.16 (10.58-45.71) and
energy expended for BMR. The reported values                        19.72 + 4.12 (10.51-43.98), respectively. Table II
for energy expenditure and physical activity were                   describes the demographical characteristics and
calculated based on the average values of the three                 anthropometric measurements of the subjects by
days of activity record.                                            gender and study group (n=618).
    The dietary intakes of the respondents were                         Self-reported energy intake and expenditure and
analysed using Nutri-Cal Professional Version 1.01                  energy balance of the subjects are shown in Table
which had the Malaysian food database(28). In cases                 III. The OW girls had significantly higher crude
where the foods or ingredients consumed were                        energy intake than the UW and NW groups (p<0.05).
not available in the database, other food databases                 Among the boys, the differences in mean crude
such as “Singapore Food Facts”(29) and “Thai Food                   energy intake were not statistically significant. When
Composition Tables”(30) were also utilised to assist                body weight was considered, the OW subjects (girls
Table I. Prevalence of underweight, normal weight and overweight male and female adolescents (n=6,555)
Gender                                              Total           UW               NW                  OW      χ2     p-value
                                                       n            n(%)             n(%)                n(%)
Male                                               3,353      498 (14.8)      2,195 (65.5)       660 (19.7)     101.6   < 0.001
Female                                             3,202        252 (7.9)     2,415 (75.4)       535 (16.7)
Total                                              6,555      750 (11.4)      4,610 (70.3)     1,195 (18.3)
BMI-for-age (WHO, 1995): <5th percentile (underweight: UW); 5th - 85th percentile (normal weight: NW);
≥ 85th percentile (at risk of overweight: OW).
                                                                                                    Singapore Med J 2006; 47(6) : 494
Table II. Characteristics of subjects by gender and body mass index (n=618).
                                                       Girls                                                   Boys
                                           UW            NW            OW           p-value        UW           NW           OW       p-value
                                         (n=72)       (n=123)       (n=122)                      (n=82)      (n=118)      (n=101)
Age (year)a                           13.0 (0.7)    13.1 (0.7)     13.2 (0.8)           ns     13.1 (0.8)   13.2 (0.8)   13.1 (0.8)       ns
Height (m)a                           1.49 (0.1)   1.51 (0.08)    1.54 (0.05)       <0.001    1.50 (0.10) 1.57 (0.09) 1.60 (0.08)     <0.001
Weight (kg)a                          32.8 (3.5)    42.6 (6.3)    64.2 (10.4)       <0.001     33.5 (5.2)   45.7 (8.3) 65.5 (11.6)    <0.001
BMI (kg/m2)a                          14.7 (0.6)    18.7 (1.9)     27.0 (3.5)       <0.001     14.8 (0.8)   18.5 (2.0)   25.5 (3.4)   <0.001
Household incomea                  1,328 (1,708) 1,082 (1,123) 1,124 (1,254)         <0.05     958 (939) 1,002 (940) 1,193 (877)       <0.01
(RM)
    0-500                              19 (26.4)     44 (35.8)     34 (27.9)                   28 (34.1)    34 (28.8)    30 (29.7)
    501-1000                           31 (43.1)     50 (40.7)     58 (47.5)                   35 (42.7)    60 (50.8)    39 (38.6)
    >1000                              22 (30.5)     29 (23.5)     30 (24.6)                   19 (23.2)    24 (20.4)    32 (31.7)
Ethnicityb                                                                           <0.05                                             <0.05
    Malay                              43 (59.7)     84 (68.3)     72 (59.0)                   51 (62.2)    56 (47.5)    48 (47.5)
    Chinese                            24 (33.3)     33 (26.8)     36 (29.5)                   16 (19.5)    46 (39.0)    43 (42.6)
    Indian                               5 (7.0)       6 (4.9)     14 (11.5)                   15 (18.3)    16 (13.5)      10 (9.9)
UW: underweight; NW: normal weight; OW: at risk of overweight
1 USD = RM 3.8; a: Mean (SD); b: n (%)
ns: not significant
Table III. Energy intake, energy expenditure and energy expended for basal metabolic rate and physical
activity by gender and body mass index (n=618).
                                                        Girlsb                                                  Boysb
                                           UW             NW            OW          p-value        UW            NW           OW      p-value
                                         (n=72)        (n=123)       (n=122)                     (n=82)       (n=118)      (n=101)
Energy intakea
Kcal/day                            1,916 (73.7) 1,903 (56.5) 2,138 (56.7)           <0.05 2,198 (92.4) 2,133 (77.1) 2,262 (84.1)          ns
Kcal/kg body weight                     59 (1.8)       46 (1.4)      34 (1.4)       <0.001      66 (2.4)      49 (2.0)     36 (2.2)   <0.001
Energy expenditurea
Kcal/day                            1,581 (24.0) 1,778 (18.4) 2,189 (18.4)          <0.001 1,917 (38.8) 2,195 (32.4) 2,871 (35.3)     <0.001
Kcal/kg body weight                     49 (0.5)       42 (0.4)      34 (0.4)       <0.001      58 (0.7)      49 (0.6)     44 (0.6)   <0.001
Basal metabolic ratea
Kcal/day                            1,091 (11.9)    1,219 (9.2) 1,500 (9.2)         <0.001 12,02 (18.8) 1,431 (15.7) 1,811 (17.1)     <0.001
Physical activitya
Kcal/day                              490 (17.7)    559 (13.6)    689 (13.6)        <0.001    715 (28.7)    763 (23.9) 1,059 (26.1)   <0.001
Energy balancea
Kcal/day                              334 (74.6)    125 (57.2)     -51 (57.4)       <0.001    281.7 (94)    -61 (79.1) -608 (86.3)    <0.001
UW: underweight; NW: normal weight; OW: at risk of overweight
a
    : Analysis of covariance controlling for ethnicity and household income
b
    : Mean (standard error)
ns: not significant
                 BMR (kJ/day)
BMR (kcal/day) = 4.184 (kJ/kcal)
and boys) had the lowest energy intake compared                                 the OW subjects (p<0.001). OW girls and boys had
to the UW and NW subjects (p<0.001). Crude                                      significantly lower energy balance (negative energy
energy expenditure and energy expended for BMR                                  balance) than NW and UW subjects (p<0.001).
and physical activity were significantly greater for                                 The mean duration in minutes of low, moderate
OW boys and girls. However, our data also showed                                and high intensity physical activities performed by
that the total energy expenditure per kilogramme of                             the UW, NW and OW adolescents is presented in
body weight for boys and girls was lowest among                                 Table IV. There was no significant difference in time
                                                                                                    Singapore Med J 2006; 47(6) : 495
Table IV. Mean duration (minutes) of low, moderate and high intensity physical activity by gender and body
mass index (n=618).
                                                  Girlsb (n=317)                                            Boysb (n=301)
Physical activity                        UW            NW              OW          p-value         UW            NW             OW        p-value
                                       (n=72)       (n=123)         (n=122)                      (n=82)       (n=118)        (n=101)
Light intensitya                   1,156 (9.4) 1,147 (7.2) 1,148 (7.2)                  ns    1,163 (9.4) 1,180 (7.8)    1,157 (8.6)          ns
Moderate intensity   a
                                     245 (8.2)     252 (6.3)       251 (6.3)            ns     207 (8.0)     205 (6.7)      218 (7.3)         ns
High intensity   a
                                      40 (3.7)      41 (2.8)        41 (2.8)            ns      69 (4.8)      55 (4.0)       65 (4.4)         ns
UW: underweight; NW: normal weight; OW: at risk of overweight
a
    : Analysis of covariance controlling for ethnicity and household income
b
    : Mean (standard error)
Light: sleeping, lying down, sitting (resting, reading, writing, playing computer and video games, watching TV, eating), standing still
(watching TV, talking, queuing)
Moderate: walking, standing with movements (washing dishes, cleaning, dusting, gardening)
High: cycling, walking up and down the stairs, running, playing sports, exercise
ns: not significant
spent in each physical activity category among the                             energy from carbohydrates (<55%).
study groups. In general, OW adolescents did not
appear to spend more time doing low to moderate                                DISCUSSION
activities compared to the UW and NW groups.                                   The high proportion of adolescents at-risk of
This, however, could also be due to misreporting                               overweight in this multi-ethnic sample was similar
of activities, especially among the overweight and                             to(9) or higher than other findings among Malaysian
obese subjects. Macronutrient intakes (carbohydrate,                           adolescents(8-11). The prevalence of at-risk overweight
protein and fat), expressed as intake in grammes and                           reported in this present study, however, may not be
as percentage of energy intake are shown in Table V.                           comparable to those reported in previous studies
When compared to the UW and NW groups, the OW                                  due to different methods and cut-offs used to
girls had the highest total grammes of macronutrient                           define overweight and obesity, age groups, ethnic
intake (p<0.05). No significant differences were                                composition and locality (urban and rural) utilised
observed for macronutrient intakes (total grammes                              in each study. Nevertheless, overweight and obesity
and percent of energy) among the UW, NW and OW                                 among children and adolescents is of a concern as
boys. All groups, however, had more than 30% of                                the problem may persist into adulthood and increase
energy from fat and relatively lower percentage of                             the risk of adult morbidity and mortality(31-33).
                                                                              Singapore Med J 2006; 47(6) : 496
    Various studies have shown that overweight or           respectively. However, The National Coordinating
obese children did not consume more energy; they            Committee on Food and Nutrition of Malaysia
consumed less energy and had higher physical                (2005), recommends that carbohydrates should
activity than their normal weight peers, yet                contribute 55-75%, fat 20-30% and proteins 10-15%
maintained their adiposity(14,17-18). However, other        of total daily energy intake.
researchers have reported that energy intake was                In comparison to the NW and UW adolescents
positively related to adiposity(13,15-16). Our findings      in this study, the OW adolescents expended more
showed that while crude energy intake did not               energy per day for physical activity and BMR.
differ significantly among UW, NW and OW male                The higher BMR among the overweight subjects
adolescents, OW female adolescents had significantly         was expected because the increase in body weight
higher crude energy intake than the other two groups.       will result in an increase in BMR(39). However, the
A mean difference in the range of 113-173 kcal/day          higher energy expended for physical activity by the
between the NW and OW male and female subjects              OW subjects remained questionable. Several studies
in this study (with the OW subjects consuming the           have shown that obese children are physically less
extra energy), could as well contribute to a weight         active than non-obese children, however, due to
gain of several pounds per year(34).                        higher body weight, the energy requirement of
    We reported that after body weight was                  the same activity in obese children is much higher
considered, the overweight subjects actually had the        than in the non-obese(40-41). Thus, the obese children
lowest energy intake compared to the subjects in the        expended more energy for physical activity than did
other two groups. Our results are similar to those of       non-obese children, yet were not necessarily more
Gazzaniga and Burns(35) in that the researchers also        active. It is also possible that the OW adolescents had
found that the 9- to 11-year-old obese children had         misreported the duration and intensity of physical
higher crude daily energy intakes but lower energy          activities which then caused an overestimation of
intake per kg of body weight than did the non-              physical activity- associated energy expenditure(42).
obese children. These findings may actually reflect               The most significant finding from this study is
systematic underreporting among the OW subjects             that when body weight is considered, energy intake
which consequently leads to the difficulty to identify       and energy expenditure are lowest among the OW
excess energy intake as the main contributor to             subjects. Gazzaniga and Burns(35) have also found
energy imbalance.                                           that among boys and girls aged 9-11 years, energy
    In children, percent of energy from dietary             intake, total energy expenditure, resting energy
fat    is    positively     related    with    increasing   expenditure and energy expended for physical
adiposity(16,19,36). Percentage of body fat has also        activity were substantially higher among obese
been shown to correlate positively with intakes of          than non-obese children; however, the total energy
total, saturated and monounsaturated fatty acids            expenditure and energy intake per kg body weight
and negatively with carbohydrate intake, even               were lower. Perhaps, among the overweight and
after adjusting for energy intake, resting energy           obese individuals, the combination of a genetically-
expenditure and physical activity among pre-                determined low fat oxidation capacity when the
adolescent children(35). Similarly, Eck et al(36) have      diet is high in fat, and a sedentary lifestyle with a
shown that children at high risk of obesity consumed        low level of energy expended on physical activities
higher percentage of fat energy but lower percentage        (contributing to a low total energy expenditure) may
of carbohydrate energy than children at low risk of         put the individuals at risk of further weight gain(43),
obesity. In contrast, Grant et al(38) reported that obese   independent of energy intake.
children did not consume significantly more energy               It is always important to highlight the limitations
from macronutrients than non-obese children.                of the study that may influence the study findings and
    In the present study, while mean total gramme           warrant caution in the interpretation of the findings.
intake of macronutrients (carbohydrate, fat, protein)       Firstly, the design of the study is cross-sectional,
was significantly higher (p<0.05) in OW than NW and          which provided information only on the overweight
UW girls, no significant differences were observed           status and not on the development of the overweight
among the OW, NW and UW boys. Unlike previous               status. The study did not obtain important information
studies, we did not find any significant difference           related to weight changes i.e. gain, loss or stable.
in percentage of energy from macronutrients by              Thus, the data could only report on the behaviours
gender and study groups. The adolescents in this            that were associated with the current weight status
study consumed 32-34%, 51-53% and 14-16% of                 and not behaviours that contribute to weight gain.
energy intake from fat, carbohydrates and proteins,         For example, excess energy intake and low physical
                                                                                 Singapore Med J 2006; 47(6) : 497
activity may be contributory factors to overweight            To promote a healthy lifestyle in children and
and obesity in adolescents, but reduced energy            adolescents, which eventually can prevent overweight
intake and high or increased physical activity may        and obesity, health promotional strategies that address
be the outcome behaviours of overweight and obese         a broad range of factors, especially environmental
adolescents in their attempts to reduce weight. The       factors that relate to eating behaviours and physical
present study, however, was not able to determine         activity, may be required. Efforts to promote healthy
the direction of these dietary and physical activity      eating habits and regular physical activities among
variables. Perhaps, future research with a longitudinal   children and adolescents must engage all segments
study design may overcome these limitations.              of the society, such as the government and non-
    Secondly, the use of three-day food and physical      government agencies, health professionals, food
activity records among the adolescents depended           industries, media, school authorities and parents, to
very much on the initiative, cooperation and honesty      help create an environment in which the children live
of the respondents to record their daily food intakes     and form their behaviours.
and activities. The act of recording food intake and
physical activity over a period of time can also lead     ACKNOWLEDGEMENT
the respondents to simplify the recording processes       The project was funded by the Intensification of
i.e. reduce the number, types and frequency of            Research in Priority Areas (IRPA) grant (project
foods and snacks eaten or types and duration of           number: 06-02-05-9005) of the Malaysian Ministry
activities performed(44). Consequently, the records       of Science, Technology and Environment.
may significantly under-report or over-report
energy and nutrient intakes and energy expenditure.       REFERENCES
Thirdly, the physical activity and energy expenditure     1. Sawaya AL, Dallal G, Solymos G, et al. Obesity and malnutrition in a
                                                              shanty town population in the city of Sao Paulo, Brazil. Obesity Res
information obtained were of crude measurements               1995; 3:107S-15S.
compared to assessments using doubly-labelled             2. Popkin BM, Udry JR. Adolescent obesity increases significantly in
                                                              second and third generation US immigrants: the National Longitudinal
water method, indirect calorimetry, heart rate
                                                              Study of Adolescent Health. J Nutr 1998; 128:701-6.
monitoring or motion sensors. In addition, the use of     3. OʼLoughlin J, Paradis G, Meshefedjian, G, Gray-Donald K. A five-
equations to calculate BMR and the assumption that            year trend of increasing obesity among elementary schoolchildren
                                                              in multiethnic, low-income, inner-city neighbourhoods in Montreal,
the energy cost for all activities in each category is        Canada. Int J Obes Relat Metab Disord 2000; 24:1176-82.
the same may introduce error in the determination         4. World Health Organization. Obesity. Preventing and managing the
of total energy expenditure.                                  global epidemic. Geneva: WHO, 1998.
                                                          5. Tee ES. Nutrition of Malaysians: where are we heading? Mal J Nutr
    Finally, the aetiology of overweight and                  1999; 5:87-109.
obesity is multi-factorial. At present, the role of       6. Lim TO, Ding LM, Zaki M, et al. Distribution of body weight, height
individual factors (e.g. dietary intake, genetic and          and body mass index in a national sample of Malaysian adults. Med
                                                              J Malaysia 2000; 55:108-28.
physical activity) and their interactions are still       7. Khor GL. Nutrition and cardiovascular disease: an Asia Pacific
inconclusive. Our study, however, did not consider            perspective. Asia Pac J Clin Nutr 1997; 6:122-42.
                                                          8. Bong ASL, Safurah J. Obesity among years 1 and 6 primary school
genetic factors which may influence the roles of
                                                              children in Selangor Darul Ehsan. Mal J Nutr 1996; 2:21-7.
diet composition, energy intake and expenditure           9. Judson JP, Jeyalingam K. Small yet large - obesity profile in
in the maintenance of overweight and obesity                  Malaysian school children. In: Ismail MN, ed. Proceedings of the 2nd
                                                              Scientific Meeting on Obesity. Kuala Lumpur: MASO, 1998: 59-68.
among the adolescents. Despite the limitations
                                                          10. Kasmini K, Idris MN, Fatimah A, et al. Prevalence of overweight
in study design and methodology, our findings                 and obese school children aged between 7 and 16 years amongst the
indicated that the overweight adolescents were not            major 3 ethnic groups in Kuala Lumpur, Malaysia. Asia Pac J Clin
                                                              Nutr 1997; 6:172-4.
consuming more energy than their non-overweight           11. Aminah A, Ain A, Suriah AR. Prevalence of obesity among Malay
counterparts, after body weight was adjusted.                 primary school children. In: Ismail MN, ed. Proceedings of the 3nd
However, compared to non-overweight adolescents,              Scientific Meeting on Obesity. Kuala Lumpur: MASO, 1999: 3-9.
                                                          12. Reilly JJ, Methven E, McDowell ZC, et al. Health consequences of
the overweight adolescents had significantly lower            obesity. Arch Dis Child 2003; 88:748-52.
energy expenditure per kilogramme of body weight.         13. Tucker LA, Seljaas GT, Hager RL. Body fat percentage of children
                                                              varies according to their diet composition. J Am Diet Assoc 1997;
Despite no significant difference in total energy
                                                              97:981-6.
contribution from macronutrients, all study groups        14. Troiano RP, Briefel RR, Carrol M, Bialostosky K. Energy and fat
had higher percentage of energy from fat (>30%)               intakes of children and adolescents in the United States: data from
                                                              the National Health and Nutrition Examination Surveys. Am J Clin
but lower percentage of energy from carbohydrate
                                                              Nutr 2000; 72(Suppl):1343S-53S.
(<55%). Our data suggested that a combination of a        15. Andersen RE, Crespo CJ, Bartlett SJ, Cheskin LJ, Pratt M.
diet high in fat (>30% of total energy intake) and low        Relationship of physical activity and television watching with body
                                                              weight and level of fatness among children. JAMA 1998; 279:938-
energy expenditure may contribute to overweight               42. Comment in: JAMA 1998; 279:959-60, JAMA 1998; 280:
and obesity among the adolescents(36,42).                     1230-2.
                                                                                                       Singapore Med J 2006; 47(6) : 498
16. Robertson SM, Cullen KW, Baranowski J, et al. Factors related to            31. Must A, Jacques PF, Dallal GE, Bajema CJ, Dietz WH. Long-term
    adiposity among children aged 3 to 7 years. J Am Diet Assoc 1999;               morbidity and mortality of overweight adolescents. A follow-up of
    99:938-43.                                                                      the Harvard Growth Study of 1992 to 1935. New Eng J Med 1992;
17. Rolland-Cachera MF, Bellisle F. No correlation between adiposity                327:1350-5.
    and food intake: why are working class children fatter? Am J Clin           32. Guo S, Roche AF, Chumlea WC, Gardner JD, Siervogel RM. The
    Nutr 1986; 44:779-87.                                                           predictive value of childhood body mass index values for overweight
18. Calderon LL, Johnston PK, Lee JW, Haddad EH. Risk factors for                   at age 35 years. Am J Clin Nutr 1994; 58:810-9.
    obesity in Mexican-American girls: Dietary factors, anthropometric          33. Must A. Morbidity and mortality associated with elevated body weight
    factors and physical activity. J Am Diet Assoc 1996; 96:1177-9.                 in children and adolescents. Am J Clin Nutr 1996; 63 (3Suppl):445S-
19. Maffeis C, Zaffanello M, Schutz Y. Relationship between physical                447S.
    inactivity and adiposity in prepubertal boys. J Pediatr 1997; 131:288-      34. Klesges RC, Klesges LM, Eck LH, Shelton ML. A longitudinal
    92. Erratum in: J Pediatr 1998; 132:747.                                        analysis of accelerated weight gain in preschool children. Pediatrics
20. Grund A, Dilba B, Forberger K, et al. Relationships between physical            1995; 95:126-30.
    activity, physical fitness, muscle strength and nutritional state in 5- to   35. Gazzaniga JM, Burns TL. Relationship between diet composition
    11-year-old children. Eur J Appl Physiol 2000; 82:425-38.                       and body fatness, with adjustment for resting energy expenditure and
21. Reybrouck T, Weymans M, Vinckx J, Stijns H, Vanderschueren-                     physical activity in preadolescent children. Am J Clin Nutr 1993;
    Lodeweyckx M. Cardiorespiratory function during exercise in obese               58:21-8.
    children. Acta Paediatr Scand 1987; 76:342-8.                               36. Eck LH, Klesges RC, Hanson CL, Slawson D. Children at familial
22. Cooper DM, Poage J, Barstow TJ, Springer C. Are obese children                  risk for obesity: an examination of dietary intake, physical activity
    truly unfit? Minimizing the confounding effect of body size on the               and weight status. Int J Obesity 1992; 16:71-8.
    exercise response. J Pediatr 1990; 116: 223-30.                             37. Obarzanek E, Schreiber GB, Crawford PB, et al. Energy intake and
23. World Health Organization. Physical status: the use and interpretation          physical activity in relation to indexes of body fat: the National
    of anthropometry. Geneva: World Health Organization; 1995                       Heart, Lung and Blood Institute Growth and Health Study. Am J Clin
    Technical Series Report No. 854.                                                Nutr 1994; 60:15-22.
24. Bouchard C, Tremblay A, Leblanc C, et al. A method to assess energy         38. Grant AM, Ferguson EL, Toafa V, Henry TE, Guthrie BE. Dietary
    expenditure in children and adults. Am J Clin Nutr 1983; 37:461-7.              factors are not associated with high levels of obesity in New Zealand
25. Poh BK, Ismail MN, Zawiah H, Henry CJK. Predictive equations for                Pacific preschool children. J Nutr 2004; 134:2561-5.
    the estimation of basal metabolic rate in Malaysian adolescents. Mal        39. Bandini LG, Schoeller DA, Dietz WH. Energy expenditure in obese
    J Nutr 1999; 5:1-14.                                                            and nonobese adolescents. Pediatr Res 1990; 27:198-203.
26. Torun B. Energy cost of various physical activities in healthy children.    40. Johnson ML, Burke BS, Mayer J. Relative importance of inactivity
    In: Schürch B, Scrimshaw NS, eds. Activity, Energy Expenditure                  and overeating in the energy balance of obese high school girls. Am
    and Energy Requirements of Infants and Children. Cambridge, MA:                 J Clin Nutr 1956; 4:37-44.
    International Dietary Energy Consultancy Group, 1989: 139-82.               41. Molnar D, Livingstone B. Physical activity in relation to overweight
27. World Health Organization. Energy and protein requirements.                     and obesity in children and adolescents. Eur J Pediatr 2000; 159
    Geneva: World Health Organization; 1985 Technical Series Report                 Suppl 1:S45-55.
    No. 724.                                                                    42. Buchowski MS, Townsend KM, Chen KY, Acra SA, Sun M. Energy
28. Tee ES, Ismail MN, Nasir MA, Khatijah I. Nutrient Composition                   expenditure determined by self-reported physical activity is related
    of Malaysian Foods. 4th ed. Kuala Lumpur: Institute for Medical                 to body fatness. Obes Res 1999; 7:23-33.
    Research, 1997.                                                             43. Astrup A. Macronutrient balances and obesity: the role of diet and
29. Department of Nutrition Singapore. Singapore food facts. Singapore:             physical activity. Public Health Nutr 1999; 2:341-7.
    Institute of Health, 2000.                                                  44. Rebro SM, Patterson RE, Kristal AR, Cheney CL. The effect of
30. Puwastien P, Raroengwichit M, Sungpuag P, Judprasong K. Thai                    keeping food records on eating patterns. J Am Diet Assoc 1998;
    food composition tables. Thailand: Institute of Nutrition Mahidol               98:1163-5.
    University, 1999.