underweight and overweight are two spectrums of nutritional disorders that result from under- and over - nutrition , respectively . due to the experience of nutrition transition in developing countries ,
while overweight and obesity in childhood as a global crisis have been linked to insulin resistance , type 2 diabetes , hypertension and coronary artery disease in adulthood , underweight in earlier life has been associated with the incidence of infection , hypertension and obesity in adulthood .
about 33% of world adult population were obese in 2005 and the projections for 2030 are that about more than 57% of adult population would be affected . in iran , national estimates indicate that almost 16% and 22% of 15 - 35 years old people are overweight and obese , respectively . published data about under - nutrition and wasting among iranian children and adolescents are scant and updated results are present for underprivileged areas .
a nationwide study concluded that 17.3% and 17.7% of iranian school students were underweight and overweight or obese , respectively .
therefore , it seems that iran faces double burden of disease ; a phenomenon that has been known in many other developing countries .
this is particularly important in deprived districts of the country zabol , a city which is located in sistan va baluchestan province , south eastern of iran .
iranian national anthropometrics nutritional indicators survey in 1988 showed that under - nutrition ( stunting ( 34.5% ) , under - nutrition ( 22.5% ) and wasting ( 7.5% ) is the major problem of this province .
another study done in 2009 showed that the prevalence of underweight , overweight , and obesity based on centers for disease control ( cdc ) are 16.2% , 8.6% and 1.5% respectively , in adolescent girls living in this province .
these rates were calculated using world health organization ( who ) , first national health and nutrition examination survey ( nhanes i ) , and international obesity task force criteria ( iotf ) , and were similar to those obtained based cdc criteria .
this study was , therefore , undertaken to estimate the prevalence of underweight , overweight , and obesity among adolescents in zabol by the use of an age - specific national and three international references ( cdc 2000 , who 2007 and iotf ) .
in this cross - sectional study , 837 adolescent ( 483 girls and 354 boys ) with the mean age of 13.2 years were selected by the use of a clustered random sampling method from adolescents studying in nine zabol guidance schools .
demographic data about age , parents education and occupation was gathered using a questionnaire filled by participants .
weight was measured by a digital scale ( seca , germany ) to the nearest 0.1 kg , without shoes and minimum clothes .
height was measured with a non - stretchable tape meter which was located on a vertical wall to the nearest 0.1 cm .
body mass index ( bmi ) was calculated as weight in kilograms divided by height in meters squared .
underweight , overweight , and obesity were defined based on suggested cut - points by four different criteria .
we used cdc 2000 , recently published cut - points by who , and iranian national cut - points . based on these cut - points ,
underweight was defined as those with bmi < 5 percentile , overweight as those with bmi between 85 and 95 percentile and obesity as those with bmi  95 percentile .
underweight , overweight , and obesity were also defined by the use of iotf suggested cut - points for bmi in 2000 and 2007 .
furthermore , mean prevalence of underweight , overweight , and obesity was compared between different criteria using analysis of variance ( anova ) and difference between each two criteria was examined using bonferroni post hoc test .
in this cross - sectional study , 837 adolescent ( 483 girls and 354 boys ) with the mean age of 13.2 years were selected by the use of a clustered random sampling method from adolescents studying in nine zabol guidance schools .
demographic data about age , parents education and occupation was gathered using a questionnaire filled by participants .
weight was measured by a digital scale ( seca , germany ) to the nearest 0.1 kg , without shoes and minimum clothes .
height was measured with a non - stretchable tape meter which was located on a vertical wall to the nearest 0.1 cm .
body mass index ( bmi ) was calculated as weight in kilograms divided by height in meters squared .
underweight , overweight , and obesity were defined based on suggested cut - points by four different criteria .
we used cdc 2000 , recently published cut - points by who , and iranian national cut - points . based on these cut - points ,
underweight was defined as those with bmi < 5 percentile , overweight as those with bmi between 85 and 95 percentile and obesity as those with bmi  95 percentile .
underweight , overweight , and obesity were also defined by the use of iotf suggested cut - points for bmi in 2000 and 2007 .
demographic differences were searched for by the use of chi - square test . furthermore , mean prevalence of underweight , overweight , and obesity was compared between different criteria using analysis of variance ( anova ) and difference between each two criteria was examined using bonferroni post hoc test .
mean age and its standard error of the studied population was 13.14  1.04 year and mean bmi was 18.5  0.13 kg / m . in the whole population ,
girls were significantly older than boys ( p < 0.05 ) while mean bmi was not significantly different among genders ( p = 0.9 ) [ table 1 ] .
overall , fathers were mostly government or self - employed and mothers worked as labor or farmer .
most of fathers in this population had high school diploma or had lower education , and this was true for males too , although this was not true for girls mothers , who were mostly illiterate .
general characteristics of zaboli adolescents * prevalence of underweight , overweight , and obesity , separately by sex are indicated in table 2 .
the highest prevalence of underweight was seen by the use of national iranian cut - off points ( 27.2% ) followed by iotf cut - off points ( 25.8% ) and their difference was not significant .
national criteria indicated that the prevalence of underweight is significantly higher among boys than that in girls ( p = 0.03 ) while this was not true for iotf criteria ( national : 31.8% vs. 25.4% ; iotf : 23.6% vs. 27.6% ) .
the use of both cdc 2000 and who 2007 cut - offs revealed a significantly lower prevalence compared to national and iotf criteria ( about 18% ) underweight while the prevalence is not statistically significant among genders ( cdc 2000 : 18.2% vs. 17.5% ; who 2007 : 17.4% vs. 19.7% ) [ table 2 ] . prevalence of underweight , overweight and obesity among zaboli adolescents based on different criteria * the use of iotf criteria revealed that over weight is prevalent among 10.8% of adolescents , without any significant difference among genders ( 9.7% vs. 11.7% ) [ table 2 ] .
when we used national , cdc 2000 and who 2007 cut - off points , we reached 2.4% , 9.4% and 8.8% prevalence rates of overweight respectively ( 2.5% vs. 2.3% for national , 8.5% vs. 10% for cdc 2000 and 10% vs. 7.9% for who 2007 ) and males did not have difference in overweight prevalence with females . using these criteria , overweight did not differ in prevalence among boys and girls while prevalence rate shown by national cut - offs was statistically different compared to other criteria [ table 2 ] .
the highest prevalence of obesity was obtained by the use of who 2007 criteria ( 7.5% for total population ) with a significant difference with other cut - offs .
although , obesity was more prevalent among boys than girls , the difference was not significant ( 8.5% vs. 6.8% ) .
obesity was significantly more prevalent in boys than girls based on all other criteria ( 4.2% vs. 0.6% for iotf , p < 001 ; 5.7% vs. 2.3% for iotf , p = 0.01 , and 2.5% vs. 0.6% for national , p = 0.02 ) .
figure 1a presents the age categorized prevalence of underweight , overweight , and obesity based on who cut - offs .
as shown the prevalence of underweight was highest among 15 years old ( 23.1% ) while overweight and obesity was mostly prevalent in 11 year adolescents ( 11.8% and 8.8% respectively ) . for
cdc 2000 cut - offs [ figure 1b ] , underweight , overweight , and obesity had the highest prevalence in 14 year ( 19.6% ) , 11 year ( 17.6 ) and 14 year ( 4.1% ) adolescents , respectively .
considering iotf cut - offs [ figure 1c ] , highest prevalence of underweight , overweight and obesity was among 15 ( 33.3% ) , 11 ( 17.6% ) and 15 year ( 3.8% ) adolescents while for national cut - offs [ figure 1d ] the prevalence was highest among 11 year ( 41.2% ) , 15 year ( 5.1% ) and 15 year ( 3.8% ) adolescents , respectively .
prevalence of underweight , overweight and obesity based on age using world health organization ( a ) centers for disease control ( b ) international obesity task force ( c ) and national ( d ) criteria
our findings indicated that underweight is prevalent among almost 18.4% and 18.7% of zaboli adolescents by the use of cdc 2000 and who 2007 cut - off points , respectively .
the prevalence rates reached 25.8% and 27.2% by iotf and iranian national criteria , respectively .
the highest prevalence of overweight was obtained by iotf cut - points ( 10.8% ) followed by cdc 2000 criteria ( 9.4% ) , while who 2007 and national iranian cut - points resulted in 8.8% and 2.4% respectively .
7.5% of the studied population were found to be obese by who 2007 definition , while this rate was 3.4% , 2.2% and 1.5% by cdc 2000 , iotf and national iranian cut - points , respectively .
our analysis also showed that iotf and national criteria reveal significantly higher prevalence of underweight , while national criteria shows a significantly lower rates of overweight , while who 2007 tend to approximate higher rates of obesity compared to other criteria in this sample .
last published report on this region of iran ( sistan va baluchistan province ) , slides back to 2009 , by montazerifar et al .
, in which they stated that prevalence of underweight is 16.2% and 10.1% based on cdc and who criteria respectively .
the prevalence of overweight was reported to be 8.6% , 8.8% and 8.4% using cdc , iotf and who criteria respectively while obesity prevalence was similar based on all mentioned criteria and was reported as 1.5% . in comparison to our results
, the prevalence of underweight , overweight , and obesity is increased , and this raise is tangible particularly for underweight .
this shows that underweight is still the major nutritional problem in adolescents living in that district of iran , while overweight and obesity are becoming more prevalent too , showing that double burden of malnutrition is becoming a problem and implementing a preventive strategies are necessary .
while underweight has its own negative consequences on health and quality of life , overweight , and obesity has long been considered as a predisposing factor that affects individual 's health . yet
, the importance of obesity and overweight among children has not been accentuated as much until recently .
overweight children and adolescents are at greater risk of being overweight as adults , and adults who are overweight are at higher risk of numerous health problems including hypertension , coronary heart disease , gallbladder disease , non - insulin dependent diabetes , and some cancers . in iran , an increasing trend in the prevalence of obesity has recently been documented in youth , and adults .
furthermore , it has been reported that the prevalence of metabolic syndrome among iranian children is comparable to those in western societies .
a high prevalence of the hypertriglyceridemic waist phenotype among iranian children has also been documented , which could make them to cluster metabolic abnormalities .
therefore , childhood obesity is a major crisis in iran that should be taken into account by health sector to use a preventive approach in this regard .
there is a lack of agreement about the definition of overweight and obesity in childhood and adolescence , and the absence of a universal definition has led to inability to monitor the worldwide development of childhood obesity .
distribution - based cut - off values , such as 85 and 95 percentiles of bmi has been proposed and used most often in literature . who has released the updated cut - off points for percentiles of bmi in 2007 . in may 2000 ,
the iotf childhood obesity working group published standard definitions for overweight and obesity in childhood .
these cut - off points were , however , not chosen on the basis of their empirical relation to risk factors ; rather , they were derived by identifying age- and sex - specific bmi values corresponding to cut - offs for overweight ( bmi = 25 ) or obesity ( bmi = 30 ) in adults .
the results of previous reports from iran and other middle eastern countries , have always been difficult to interpret as they have relied on different definitions and until now there is no report on the prevalence of overweight comparing iranian national cut - points with those of who 2007 , cdc 2000 and iotf in children and adolescents ; the dorosty et al .
study , however , did compare iranian national reference cut - points with those of iotf but this was done only in children aged 2 - 5 years residing in rural provinces of iran .
therefore , the information provided by this study shed light to some extent on the magnitude of the problem based on different definitions .
our findings reflect the difference in prevalence estimates based on different definitions . in the whole population , estimates of underweight obtained from cdc 2000 cut - points were lower than those obtained by using national or iotf , while no significant difference in the estimates was found between cdc 2000 cut - points and who 2007 cut - offs . getting back to the prevalence of overweight and obesity , estimates obtained by the use of iranian cut - points were lower than those found by cdc 2000 , iotf and who 2007 cut - offs .
other investigators have also showed a discrepancy in estimates based on different criteria in other countries .
showed that prevalence of overweight and obesity are always lower with iotf criteria than the national criteria , even in usa .
. showed that the prevalence of overweight by using iotf cut - points was significantly higher in the 2 - 3 years iranian children than when using iranian cut - points .
however , we have no children aged 2 - 3 years in the present study .
the recently recommended cut - off points for bmi in iranian children have provided us the opportunity to identify prevalence based on national criteria .
our study gives appropriate data against which estimates from other studies in middle eastern countries and elsewhere can be compared with the same methodology .
the double burden of disease we found in the current study is not unique for iranian children . among turkish adolescent girls , the prevalence of underweight , overweight , and obesity
have been reported to be 11.1% , 10.6% and 2.1% , respectively . in a similar study in qatari adolescent girls ,
the prevalence of underweight among chinese youngsters aged 15 - 20 was has been reported to be 35.9 . therefore , despite the rising trend of obesity worldwide , problems of malnutrition and nutrient deficiencies still dominate the public health nutrition agenda in our area .
first , using a population representative sample of zabol , we found the coexisting high prevalence of underweight and overweight in iranian population of children and adolescents .
second , the lack of definition - based comparative studies from this part of the world makes our study findings interesting .
our participants were selected only from zabol one of the big cities of sistan va baluchistn province , while the situation may be different particularly in rural areas .
studies with bigger sample size which cover both urban and rural areas of this economically deprived province are recommended .
this study indicates the coexisting high prevalence of underweight and overweight among guidance - school students of zahedan , iran . because nutritional patterns and physical activity behaviors develop during childhood , preventive approaches addressing children and adolescents are required to deal with the problem of underweight , overweight , and obesity .
 background : obesity and overweight are the major health problems in iran . the aim of this study was to determine the prevalence of overweight and obesity among adolescents living in zabol settled in sistan va baluchistan , one of economically underprivileged provinces in south eastern of iran , based on four different definitions.methods:this cross - sectional study was accomplished among a sample of 837 zaboli adolescents ( 483 males ; 354 females ) aged 11 - 15 years . 
 anthropometric measurements including weight and height were measured and body mass index ( bmi ) was calculated . 
 sex - specific bmi - for - age reference data of the iranian national data , centers for disease control data ( cdc 2000 ) , international obesity task force data ( iotf ) and recent world health organization ( who ) data was used to define overweight and obesity.results:mean age of the studied population was 13.14 year . 
 underweight was prevalent among almost 18.7% and 18.4% of adolescents by the use of who 2007 and cdc 2000 cut - off points . 
 the prevalence rates reached 25.8% and 27.2% by iotf and iranian national criteria , respectively . 
 the highest prevalence of overweight was obtained by iotf cut - points ( 10.8% ) followed by cdc 2000 criteria ( 9.4% ) , who 2007 ( 8.8% ) while national iranian cut - points resulted in the lowest prevalence ( 2.4% ) . 
 7.5% of the studied population were found to be obese by who 2007 definition , while this rate was 2.2% , 3.4% and 1.5% by iotf , cdc 2000 and national iranian cut-points.conclusions:almost all definitions revealed coexistence of underweight , overweight , and obesity among zaboli adolescents . 
 huge differences exist between different criteria . to understand the best appropriate criteria for iranian adolescents , future studies should focus on the predictability of obesity - related co - morbidities by these criteria . 