adolescence is a vulnerable period for the development of obesity and also appears to be a critical period for establishing risk factors for some chronic diseases in adulthood .
available statistics indicate that an alarming proportion of people in most arab countries suffer from obesity .
studies have revealed that the prevalence of overweight and obesity among adolescents in arab countries ranges from 18% to 44% . in general ,
overweight has been found to be more prevalent than obesity in both boys and girls .
however , the prevalence of obesity by gender at the adolescent stage ( 1018 years ) does not indicate the same trend . in countries such as bahrain , egypt , tunisia , kuwait , and qatar
obesity is also higher among adolescent girls than boys in bahrain , egypt , and kuwait . in some countries such as lebanon and the united arab emirates ( uae ) ,
obesity management is an important step in the prevention and control of chronic noncommunicable diseases , such as cardiovascular disease , diabetes , hypertension , and some kinds of cancer .
therefore , understanding the prevalence of obesity among schoolchildren is essential to any strategy for combating obesity in the community .
although , there is information about obesity among schoolchildren in some arab countries , there is a lack of such data for other countries such as algeria , djibouti , libya , somalia , sudan , palestine , and yemen .
however , there are two main reservations about using the available data on obesity among schoolchildren : ( a ) the use of such a wide age range ( 618 years ) does not take into consideration the prepuberty and puberty stages which have a significant effect on weight gain ; ( b ) the use of different reference standards and cutoffs to determine obesity in turn provide different rates of overweight and obesity . in bahrain ,
for example , al - sendi and colleagues   used three different sets of criteria to determine the prevalence of obesity among adolescents aged 1217 years , ( iotf , who , and cdc references ) .
they found that there was a considerable variation in the prevalence of obesity between these standards .
in general , the who reference standard gave a higher prevalence of obesity , but a lower prevalence of overweight than other standards .
the objectives of this study , therefore , were to provide the prevalence of overweight and obesity among adolescents within a narrower age range of 1518 years using the iotf reference standard , and to find out the cross - cultural differences in the prevalence of obesity in seven arab countries , namely , algeria , jordan , kuwait , libya , palestine , syria , and uae .
it is a part of the arab - eat project , which aims to study obesity and eating disorders , and barriers to healthy eating and physical activity in large cities in arab countries .
the target population of this study was adolescents in secondary schools ( 1518 years ) .
the minimum sample size in each city calculated as the sample size within 0.05 of the population proportion with a 95% confidence level .
a multistage stratified random sampling procedure was used to select the subjects . at the first stage , each city
was divided into administrative regions , which varied from two to five regions , depending on the countries .
were included , due to the difficulty in obtaining permission from private schools and the lack of data regarding these schools . at the second stage , classes were selected for each secondary level ( levels 10 , 11 , and 12 ) in each school using a simple random method .
therefore , the number of adolescents selected varied , based on the number of students in each class and the number of selected schools , which in turn depended on the total secondary school population in each city . to assure the accuracy and consistency of the methodology ( sampling procedure , measurements , and collection of the data ) , a standardized protocol was prepared and distributed to all the participating centres in the seven countries .
each centre was responsible for training its research team and obtaining ethical authorization and approval from the governmental institutes ( generally the ministry of education ) .
the total sample size in the seven arab countries was 4698 adolescents ( 2240 boys , 2458 girls ) , ranging from a total of 459 students in algeria to 1062 in syria .
it is worth noting that due to the difficulty in obtaining permission from one administrative region in an algiers city , the number of selected schools in that case represented two geographical regions instead of three .
height was measured to the nearest centimeter with the subject in full standing position , using a calibrated measuring rod .
data were first entered in an excel file , the entered data were then sent to the central processing station ( bahrain ) , along with the questionnaires for cleaning the data and carrying out the analysis , using the spss statistical package . the international obesity task force ( iotf )
reference standard was used to classify the adolescents into three categories : nonobese , overweight , and obese .
data for age , weight , height , and bmi were presented as means and standard deviations .
one way anova was used to determine the differences in anthropometric measurements between countries , and between males and females .
the sample sizes , means , and standard deviations for age , weight , height , and body mass index of adolescents ( 1518 years ) according to gender in seven arab cities are presented in table 1 .
the mean age is very close among the seven countries , ranging from 16.15 years in libya to 16.96 years in algeria .
significant differences in age , between sexes and among countries were revealed using one way anova . in general , males were significantly heavier than females in all countries .
kuwaiti adolescents showed the highest mean weight among both males ( 82.7  23.1  kg ) and females ( 65.1  20.5  kg ) ; whereas , the lowest mean weight for males was observed in algeria ( 64.0  10.9  kg ) , and for females was found in uae ( 54.6  14.2  kg ) .
algerian adolescent males showed the highest mean height ( 173.4  7.2  cm ) , while the highest mean for females was observed in jordan ( 162.1  5.7  cm ) .
the lowest mean height was found in libya for both males ( 167.4  7.4  cm ) and females ( 157.9  5.5  cm ) . as for bmi ,
the highest mean was found in kuwait for both males ( 28.1  7.5  kg / m ) and females ( 25.6  7.7  kg / m ) .
the differences in weight , height , and bmi were analysed using one way anova and were statistically significant between the seven countries for both genders ( p < 0.000 ) .
the prevalence of overweight and obesity among adolescents in seven arab cities using the iotf standard according to gender is shown in table 2 . among males ,
overweight was most prevalent among kuwaiti adolescents ( 25.6% ) , followed by jordanian ( 21.6% ) , and syrian ( 19.7% ) adolescents ; while among females , the highest prevalence was found in libya ( 26.6% ) , followed by kuwait ( 20.8% ) , and syria ( 19.7% ) .
regarding obesity , kuwaiti adolescents showed the highest prevalence among both males ( 34.8% ) and females ( 20.6% ) . in general , obesity was more prevalent among males than females in all countries included in this study .
figures 1 and 2 illustrate the comparison of the prevalence of overweight and obesity among adolescent males and females in the seven arab countries , respectively .
kuwaiti males showed the highest prevalence of overweight and obesity ( 60.4% ) , while the lowest prevalence was reported in algeria ( 13.4% ) .
as for females , the highest prevalence was also found in kuwaiti females ( 41.4% ) and the lowest prevalence was in palestinian females ( 16% ) .
a comparison between the iotf and cdc reference standard for the prevalence of overweight and obesity among adolescents ( 1518 years ) in seven arab countries is presented in table 3 .
in general , the cdc reference provided a lower prevalence of overweight and higher prevalence of obesity than the iotf reference .
for example , the prevalence of overweight in algerian males was 9.3% based on the iotf reference , compared with 4.6% based on the cdc reference .
  this paper has presented for the first time a comparison of the prevalence of overweight and obesity in seven arab countries using a similar methodology and reference standard ( iotf ) .
the findings have revealed a relatively high percentage of overweight among adolescents ( 1518 years ) in all countries studied , ranging from 9.3% in algeria to 25.6% in kuwait . as for obesity ,
the prevalence was higher in males than females , and ranged from 4.1% in algeria to 34.8% in kuwait .
it is difficult to compare the findings of this study with many previously published studies because of the differences in the standard used and in the age range .
moreover , there has been an absence of published data on adolescent obesity in some arab countries included in this study , such as algeria , libya , and sharjah .
however , when the results of this study are compared with those reported in kuwait for 1419 year olds using the iotf standard , we noticed that the present data showed a higher prevalence of obesity among boys ( 34.8% versus 24.8% ) , and a similar finding among girls ( 20.6% versus 20.0% ) .
as for overweight , the findings of this study were 25.6% for boys , compared with 18.8% in the previous study , and the equivalent proportions for girls were 20.8% and 25.3% , respectively .
it is important to mention that there was a 610 years gap between the two studies , and we can observe that obesity is increasing among male kuwaitis , but not among females .
similar findings were seen when we compared the present data for sharjah ( uae ) with the national data for uae adolescents aged 1019 years , using same reference standard ( iotf ) .
there was an increase in proportion of obesity among males ( 19.1% versus 13.2% ) , but a decrease in females ( 6.6% versus 11.0% ) . for overweight
nevertheless , it is difficult to reach a concrete conclusion , since we are comparing national data with regional data and a different age group .
therefore , it is necessary in any national information on obesity to show the regional differences in the obesity proportion . the high prevalence of overweight and obesity among some arab countries , especially in kuwait , could be due to rapid nutrition transition , which started earlier in kuwait than in other countries .
in addition , kuwait has the highest socioeconomic status among these countries , which may contribute to the increase in the prevalence of obesity . in general ,
the difference in the prevalence of obesity between the seven arab countries can be attributed to several factors such as ethnicity , economic status , physical activity , dietary habits , timing of puberty , and genetic admixtures [ 12 , 13 ] .
overweight and obesity were more prevalent among males in jordan , kuwait , and uae , than among females .
bmi is an expression of weight related to height , not adiposity , and there is no standard definition of adiposity or excess body fat in childhood against given bmi levels in the arab countries .
the higher prevalence of obesity among males compared to females in some arab countries may be related to the difference in timing of puberty , muscular tissue , and dietary habits between boys and girls .
the association between obesity and the timing of puberty differs among populations [ 13 , 15 ] .
the prevalence of overweight and obesity among adolescents ( using different reference standards ) in previous reports in jordan , kuwait , palestine , syria , and uae   is relatively high , which is also confirmed by this study .
this study has also suggested a high prevalence of overweight and obesity in middle - income countries , such as libya , and in poor countries , such as palestine . a plan of action to prevent and control obesity should be urgently established in the arab countries , especially among children and adolescents to combat the comorbidities associated with obesity .
this study provides comparable and useful data to build on for this plan of action .
we hope that this study will stimulate researchers in other arab countries to carry out similar surveys to compare obesity in this region .
 
 objective . 
 the aim of this study was to find out the prevalence of overweight and obesity among adolescents in seven arab countries using similar reference standard . methods . 
 a school - based cross - sectional study was carried out in seven cities in arab countries , namely , algeria , jordan , kuwait , libya , palestine , syria , and united arab emirates . 
 a multistage stratified random sampling technique was used . 
 the total sample included was 4698 adolescents aged from 15 to 18 years ( 2240 males , 2458 females ) . the international obesity task force ( iotf ) 
 reference standard was used to classify the adolescents as nonobese , overweight , and obese . results . among males , 
 overweight was highest among kuwaiti adolescents ( 25.6% ) , followed by jordanian ( 21.6% ) , and syrian ( 19.7% ) adolescents . among females , the highest prevalence of overweight 
 was reported in libyan adolescents ( 26.6% ) , followed by kuwaiti ( 20.8% ) , and syrian ( 19.7% ) adolescents . as for obesity 
 , kuwaiti adolescents showed the highest prevalence of obesity for both males ( 34.8% ) and females ( 20.6% ) . 
 conclusion . 
 there is an urgent need to establish a plan of action to combat obesity in schoolchildren in these countries . 
1. Introduction
2. Methods
3. Results
4. Discussion