Prevalence and sociodemographic correlates of stunting, underweight, and overweight among Palestinian school adolescents (13-15 years) in two major governorates in the West Bank

Malnutrition during adolescence has important short and long-term health implications. Adolescent obesity has been associated with adverse cardiovascular [1], metabolic [2] and psychological outcomes [3]. Tracking of obesity from adolescence to adulthood has been shown to be high [4], and obesity in adulthood is associated with chronic diseases and increased mortality [5]. At the same time, undernutrition during childhood has been linked to higher risk of obesity and chronic diseases in adulthood [6].

The rise in obesity and chronic diseases worldwide has been linked to urbanization, which entails nutrition transition and sedentary lifestyle [7]. Compared to western societies, Middle Eastern countries experienced a later but faster-paced nutrition transition [8]. Palestinian society has also been undergoing nutrition transition [9], where studies have shown nutrition-related chronic diseases and their risk factors such as heart diseases, hypertension, diabetes, cancer, smoking, sedentary lifestyle and obesity to be prevalent among Palestinians [9]. One study among adults estimated combined prevalence of overweight and obesity to be 58.7% among men and 71.3% among women [9]. At the same time, stunting which is associated with chronic undernutrition, has been increasing among Palestinian children younger than 5 years of age from 7.2% in 1996 to 10.2% in 2006 [10].

Studying various aspects of the nutritional status of Palestinian adolescents (10-19 years) is important as they represent about one-quarter of the Palestinian population [11]. Studies exploring nutrition-related aspects of Palestinian adolescents in the West Bank are few. One national study which was part of the Health Behaviour in School aged Children Survey (HBSC) was conducted in the West Bank and the Gaza Strip in 2003/2004. In that survey, prevalence of overweight/obesity (using International Obesity Task Force (IOTF) criteria) was estimated at 20.4% for boys and 13.0% for girls [12]. However, calculation of body mass index (BMI) in that survey was based on self reported weights and heights rather than on actual measurements. Moreover, undernutrition (stunting and underweight) was not assessed. To our knowledge, no population based studies have reported actual measured anthropometric data for underweight, overweight, obesity and stunting among adolescents in the West Bank. Therefore, there is a need to conduct such studies to be able to identify the vulnerable groups and plan proper intervention programs.

The West Bank in the occupied Palestinian territory (oPt) is an area of 5655 square Km with 2 350 583 inhabitants and is composed of 11 governorates (governorate is official administrative division of the oPt) [11]. This study was conducted in two main governorates in the West Bank (Ramallah and Hebron governorates) chosen for their contrasting demographic and lifestyle features and for their importance in terms of economic status and population size. Ramallah governorate is located in the middle of the West Bank with 279,730 inhabitants in 2007 [11]. It has 6 urban and 69 rural localities with 34.1% and 59.5% of the population, respectively [13]. Ramallah city is a cultural, political, and administrative center of the Palestinian Authority. Hebron, which is the largest governorate in terms of population size, is located in the southern part with 552,164 inhabitants in 2007 [11]. It has 10 urban and 144 rural localities, with 67.0% and 30.2% of the population, respectively [13]. In a comparison of demographic and lifestyle characteristics such as fertility levels, age of women at marriage, education levels, types of employment, and the availability of modern household amenities, Ramallah and Hebron cities represented two distinctive modes of urban life with Ramallah being more modernized and having a higher standard of living [14]. Corresponding rural areas showed similar pattern with those of Ramallah having better indicators than those of Hebron. The differences between the cities and their rural areas in these indicators were more pronounced in Ramallah than in Hebron [14].

The objective of this article was to assess the prevalence of stunting, underweight, overweight, and obesity using actual measured weights and heights among school-based adolescents (13-15 years) in 2 major governorates (Ramallah and Hebron) in the West Bank in the oPt. It also aimed to study the associations between these anthropometric measurements and selected sociodemographic characteristics such as residential factors (region, urban-rural), age, gender, educational level of the parents, aspects of household economic situation, and food availability.

Results of selected height and weight measurements for assessing nutritional status and their sociodemographic covariates in a sample of Palestinian adolescents aged 13-15 years from the two major West Bank governorates, Ramallah and Hebron, are reported. The findings revealed that conditions related both to overnutrition and undernutrition are present in these two governorates. Higher prevalence of overweight/obesity was found among Ramallah adolescents compared to their counterparts in Hebron and a higher prevalence among girls than boys in both governorates is reported. The prevalence rates of underweight and stunting were higher among boys than among girls in both governorates.

Girls were slightly over-represented in the sample because there were slightly more girls than boys in these two grades in schools. Most of the students were in the 13 and the 14 years age groups because these are the most common age groups attending the 8^th and the 9^th grades. Fewer of the 9^th grade students, and less frequently 8^th grade students, would be in the 15 years age group. The proportion of the younger age group (age group 13) was slightly higher and that of the older age groups (14 and 15 years age groups) was slightly lower in Ramallah than Hebron because the proportion of 8^th grade students in Ramallah governorate was higher than that in Hebron governorate.

In our study, indicators of both present and past family wealth were used. Closures of Palestinian areas, and recurrent curfews since the second Intifada in 2000 have led to a rise in poverty [20] with 34% of Palestinians reported to be food insecure in 2006 [21]. The STL index, reflecting past wealth, is amenities-based and is similar to what has been used in other surveys on adolescents [17, 22]. It is thought to be useful in this age group as many are unable to provide substantive information on their parents' occupation and income [23]. The amenities included in this index are culture specific for Palestinians and are listed among those used by PCBS for assessment of material standards of living [24]. In contrast, the present household economic situation index, reflecting recent deterioration in wealth, was based on reports of current economic hardships and financial coping mechanisms. The weak correlation between STL and the present household economic situation index (0.42) suggests that they reflect different aspects of family affluence.

Affluence and urban lifestyle are associated with a higher prevalence of overweight in lower and middle income developing countries [7]. This was the case in this study where adolescents in Ramallah governorate had a higher prevalence of overweight/obesity than in Hebron; probably due to higher standards of living [14]. Adolescents in Ramallah had better indicators of economic situation such as STL index and the present household economic situation index. They also had better social indicators such as smaller family size. Furthermore, the prevalence of overweight/obesity was higher in urban areas and among those with high STL and this was more pronounced among boys. Similar associations of overweight among boys with high family affluence scale were found in the Palestinian HBSC study [12].

Overweight/obesity was higher among girls than boys. In Palestine, boys are reported to be more physically active than girls [25]. Cultural restrictions on girls imply that they spend more time indoors and thus have easier access to food. These findings are similar to those found in a 2002 North Gaza Strip study, in which 15.4% of the boys and 20.2% of the girls aged 12-15 years were found to be overweight/obese (using the 2000 CDC reference) based on measured weights and heights [16]. However, the validity of this comparison may be questionable now as the economic situation has deteriorated considerably in Gaza since 2002 [20]. An opposite trend in gender difference was found in the Palestinian HBSC survey conducted among adolescents aged 12-18 years in 2003/2004 in the West Bank and the Gaza Strip. This survey reported overweight/obesity (using IOTF criteria) of 20.4% among boys and 13.0% among girls [12], while in our study the corresponding percentages by the same criteria were higher in girls (22.2% in Ramallah and 16.9% in Hebron) than in boys (18.5% in Ramallah and 13.1% in Hebron). One explanation might be that the Palestinian HBSC study used self-reported weights and heights. Self-reported data tend to underestimate overweight prevalence, especially among girls [26]. Moreover, the age groups were different between the HBSC study and our study, and the sample in our study was selected from only two governorates in the West Bank while the HBSC study was a national-level study in the West Bank and the Gaza Strip. In the Palestinian HBSC study, 27.5% of the data was missing for BMI. In contrast, there was no missing data in our study.

A 2003-2004 national survey of Jewish and non-Jewish Israeli school adolescents (aged 11-19 years) found that among boys, the prevalence of overweight/obesity (using the 2000 CDC reference), based on measured heights and weights, was 19.6% for Jews and 22.6% for non-Jews (mostly Arabs and Druze) while in girls it was 15.7% for Jews and 20.3% for non-Jews [27]. Also in this case, the gender difference was opposite to the findings in our study. Such a comparison should also be taken with caution because of a much wider age range and sampling frame in this study compared to our more limited study. In Lebanon, boys in private schools (aged 12.5-15 years) in 2002-2003 were found to have higher rates of overweight and obesity than girls using measured weights and heights. The prevalence of overweight and obesity (using IOTF criteria) among boys was 29.2% and 8.7%, respectively. The corresponding figures for girls were 18.7% and 3.7%, respectively. Western feminine self-image and fears of obesity were more marked among Lebanese girls than boys [28].

Studies in the Gulf areas, enjoying higher standards of living than the West Bank, showed a higher prevalence of overweight/obesity than our figures. Some of these studies showed higher prevalence of overweight/obesity among boys and other studies showed higher prevalence among girls. A study in 2003-2004 among Qatari adolescents aged 12-17 years found a prevalence of overweight and obesity based on measured weights and heights (using IOTF criteria) of 28.6% and 7.9% among boys, respectively and 18.9% and 4.7% among girls, respectively [29]. In contrast, studies in 2000 in Bahrain among adolescents aged 12-17 years found a higher rate of overweight and obesity among girls based on measured weights and heights. The prevalence of overweight and obesity among boys (using IOTF criteria) were 15.3% and 14.9%, respectively while the corresponding figures for girls were 24.5% and 17.9%, respectively [30].

As reported in other studies [22], overweight/obesity was associated with family size. The mean family size in the West Bank is 5.5 [11]; however, it was larger in our study (8.1 in Ramallah and 8.9 in Hebron) as the sample represents a selected segment of families that have progressed further into their life cycle.

The prevalence rates of underweight were lower in Ramallah than in Hebron. Multivariate regression analysis showed that underweight was negatively associated with residence in Ramallah among girls and with high STL among boys. Stunting rates were similar in both governorates. Both underweight and stunting were higher among boys than among girls in both governorates. The same pattern between boys and girls of higher underweight (7.0% versus 3.8%) and higher stunting (13.7% versus 6.2%) among boys was reported in the 2002 Gaza study [16]. Similar patterns of higher underweight [29] and higher stunting among boys [31, 32] have been also found in other developing countries. Higher stunting among Palestinian boys might indicate that they suffer from micronutrient deficiencies as they are prone to make less healthy food choices [25], or it could be due to age-specific differences in catchup growth between the sexes [33]. Stunting might also be associated with parasitic infections as suggested by some studies in developing countries [34]. A recent study from Gaza strip showed that the prevalence of intestinal parasites was 34.2% in children aged 6-11 years [35]. Since we neither could find recent data nor collected such data in the West Bank, we may only speculate if the higher prevalence of stunting in boys could be due to higher risk of infections as boys spend more time outdoors than girls. The prevalence of stunting among girls was low in general, but it was relatively high among girls living in rural areas and among those with low STL. Short stature may have an impact on girls and their reproductive outcomes; this may be even more important in the Palestinian context given the young median age of first marriage of 18 years and the high total fertility rate of 4.6 [10]. Onset of puberty was positively associated with overweight/obesity and negatively associated with stunting and underweight. This might be explained by a larger proportion of the well nourished amongst those who have reached puberty in the sample. Similar association of overweight/obesity with onset of puberty has been found in other studies [16, 22]. Although asking about Tanner stage would have given a more precise measure of sexual maturation, cultural taboos did not permit this.

The study had certain limitations such as not including adolescents out of schools. The sample was not a national sample which makes it difficult to generalize the results to the whole of the oPt and limits the opportunity to compare our findings with similar data from other countries in the region. The sample was based on 8^th and 9^th grade students and the results reflect the prevalence of anthropometric measures in these two grades only. The corresponding age groups were mainly 13 and 14 years old, while the age group of 15 years was relatively small. Weights and heights were taken only once by one field worker, so that some measurements errors might not be accounted for.

The student's questionnaire was not validated, but some questions were taken from the validated HBSC questionnaire [17] and field workers were present when administering the questionnaire to explain questions when needed. A pilot study was done and unclear questions were modified. Moreover, the questionnaire was tested for reliability (a 1-week test-retest). The measures for the onset of puberty and household amenities had very high agreement between test and retest. The 1 week test-retest for the onset of puberty showed consistent answers in 92.3% in boys and 95.2% in girls, and that of the ownership of household amenities showed consistent answers ranging between 86.1% and 99.1%. Other strengths of the study include the fact that actual measurements of the weights and the heights were taken, its relatively large sample size, single stage cluster sampling method, the urban/rural distribution, and the high response rate. We also studied the association with certain sociodemographic characteristics to identify the vulnerable groups for malnutrition.

Our findings suggest that both overnutrition and undernutrition coexist in the study areas. This stage of nutrition transition is similar to low income economies where both under- and overnutrition coexist [36] and where overnutrition is more prevalent among the more affluent strata of the society [7]. Both conditions may predispose to chronic diseases later in life. Urbanization, poverty, limited mobility and cultural restrictions on girls may all play a role.

Future studies should address causes of overnutrition and undernutrition among Palestinian adolescents with relevance to preventive measures that could be instituted by the Palestinian health system given its limited resources. There is urgent need to improve nutrition to combat stunting, and to raise awareness about overweight and its associated health risks.