obesity is considered one of the most remarkable medical and social problem in western societies . in particular , childhood obesity is rapidly emerging as a global epidemic with a great variation in secular trends across countries [ 1 , 2 ] . it is estimated that in the near future over 26 million children in the european countries will be overweight or obese . this trend will have profound public health consequences since obese children tend to become obese adults [ 4 , 5 ] . a review of the literature related to the years 19701992 revealed that 4263% of obese children in the usa have become obese adults . childhood obesity is associated with a plethora of psychosocial disorders   and health risks including cardiovascular disease risk factors [ 8 , 9 ] . in italy , the national institute of research on food and nutrition ( inran ) carried out with the collaboration of local public institutions a survey to assess the prevalence of overweight and obesity among 810 years old children of 6 regions distributed from north to south during the years 20002002 . the study demonstrated that 23.9% of children were overweight and 11.1% of the sample were obese , highlighting one of the highest prevalence in the european countries . the distribution of obesity was not homogeneous , showing a higher prevalence in the southern areas compared to that of the northern areas . such trends were confirmed by the results of the national survey carried out recently on children of the same age and that showed the following prevalence of overweight and obesity : 23.6% and 12.3% . paediatric obesity in european countries is a common problem and studies were performed to identify risk factors and action plans for obesity prevention and treatment [ 11 , 1315 ] . the aetiology of obesity is extremely complex , and it is generally linked to many factors that are not only of genetic type . most of the time personal lifestyle choices as well as cultural , environmental , and behavioural factors , significantly influence obesity [ 16 , 17 ] . research findings have shown that many dietary habits are highly correlated to obesity , and physical activity or other lifestyle behaviours are important covariates . they are considered  universal  risk factors for overweight youth   and are identified in the increasingly toxic and obesogenic environments of our societies , specially of developed countries , although their relative causal significance is not well understood [ 20 , 21 ] . in particular , the eating habits of italian school aged children and adolescents are involved in a changing process from the more traditional mediterranean diet , to more westernized eating models , rich in animal proteins , fat , and with low intake of complex carbohydrates and fiber [ 2224 ] . this , together with a decrease in energy expenditure , probably , contributes to the increase of the obesity prevalence [ 15 , 25 ] . however , most of the studies performed in italy on school children focused on the estimation of the prevalence of overweight and obesity [ 11 , 12 ] or on the estimation of the average food and nutrient intakes [ 22 , 23 ] . the purpose of the present pilot study was to provide data on the association of paediatric overweight and obesity with possible risk factors . in the years 2004/2006 , we studied 756 adolescents ( 391 males and 365 females ) , mean age 12.4  0.9 , belonging to three public middle schools of a roman urban area . prior to their acceptance , the adolescent 's parents or others caregivers were fully informed about the objectives and methods of the study and signed a consent form which included self - reported   weight and height and children 's weight at birth and if the child had been or not breastfed . height and weight were measured in triplicate in the school setting , in the morning according to who international guidelines . weight was measured in underwear by a regularly calibrated battery - operated digital scale ( seca 8129 ) to the nearest 0.1  kg ; height was measured by a portable stadiometer ( promes ) to the nearest 0.1  cm . to assess levels of overweight and obesity , we used international obesity task force ( iotf ) cut offs . we used bmi because it can be at group level an appropriate index to define overweight in children and adolescents . information concerning the time dedicated to organized sport activities   and to other after school physical activities   such as running , jumping , bicycle riding , or playing soccer , and the estimation of the time spent at the computer or watching tv were obtained by means of a questionnaire by an in - depth interview to the students during the anthropometric measurement sessions . the physical activity questions were based on those used for the validated adolescent physical activity recall questionnaire , to investigate on organized sport and nonorganized physical activity out of school and during weekends . the sedentary activity questions we adopted match the ones of the validated adolescent sedentary activity questionnaire [ 30 , 31 ] . the dietary assessment was based on a 24-hour dietary recall assisted by food records : this method is considered adequate when sample size is sufficiently large . the delivery of the  form  was the occasion to gather through recall data on the last meal consumed ( breakfast ) and for training the adolescents in advance on how to keep complete and accurate records of all food and beverages as they were consumed through the day , without quantification of the portion size . this food registration served solely as a memory prompt during the recall   conducted by well trained and standardized dieticians the day after . during the face - to - face interview , the dietician estimated the amount of each food eaten , with the assistance of a visual support that reported standard household measures or portions of the common italian foods . another task of the dietician was to collect further details about recipes , food description , preparation practices , and information about students being or not on a diet . the calendar of the food survey was organized in order to represent an adequate proportion of weekdays and weekend days . dietary data were carefully checked and entered by interviewers into a nutrition software system inran - diario 3.1 developed by inran . this system translates the amount of food eaten into individual energy and macronutrients and assigns consumed foods into food groups and subgroups . the bmi values were initially recoded into three categories : normoweight , including underweight and normal weight children ( the number of underweight children was very small ) , overweight , and obese . associations between overweight status and physical / sedentary activities ( sports activities outside of school , hours of sports activities , hours of playing outside of home , hours of watching tv ) , lifestyle characteristics ( eating breakfast , number of meals per day , being on a diet ) , energy and macronutrients intakes , and other information ( birth weight , breastfeeding , overweight / obesity status of mother and father ) were also investigated . only two categories of bmi values were considered to study these associations , namely , normoweight and overweight , arranging overweight and obese in a single category . the associations between bmi categories and each numerical variable were tested by the kruskal - wallis test , while the chi - square test evaluated the associations with categorical variables . all reported probability values ( p values ) were compared to a significant level of  .05 . multiple logistic regression [ 35 , 36 ] was used to estimate the relationship between students ' food habits , lifestyle , and other information , and their likelihood of being overweight by calculating the odds ratios ( or ) and the corresponding 95% confidence intervals ( cis ) ; p values associated with tests for linear trend in the or were also provided . a first logistic regression model evaluated to what extent the intakes of different food categories were associated with overweight status . for this purpose , tertiles of food intake were calculated for each distribution and the levels of each food item were recoded into low consumption if lower or equal to the inferior tertile , medium if between the inferior and the superior tertile , and high if equal or higher than the superior tertile . or and associated 95% ci are presented for each level of the variables in comparison with the high referent level . correlation of each food group with other food groups entered in the model was calculated and the presence of high multicollinearity was excluded . a second logistic regression model evaluated to what extent lifestyle characteristics , energy and macronutrients intakes , birth weight , breastfeeding , being on a diet and parent bmi were associated with overweight status . the number of meals per day was recoded into three categories : 2 - 3 , 4 - 5 , and 6 - 7 . hours of sports and hours of watching tv were both recoded into two categories ( 03 and more than 3 , 02 and more than 2 , resp . ) . both mother 's and father 's nutritional status were recoded into normoweight ( including underweight and normal ) and overweight ( including obesity ) . tertiles of distribution were calculated for total daily energy , fats , proteins , and carbohydrates intakes and the levels were recoded into low , medium , and high as described above for food intake . variables that showed an association with bmi status in the previous univariate analysis were included in the models , some other independent variables were included through forward selection . table 1 presents the distribution of bmi categories by age , stratified by gender . overall , 28% of the boys and 24% of the girls were overweight ; 9% of boys and 7% of girls were obese . overweight / obesity status showed high rates in 12 and 13 aged boys while it tended to decrease with age in the girls group . fewer overweight boys played sports outside of school compared with normoweight ones ; moreover , overweight students of both genders spent less time in sport activities with respect to the normoweight ones ; overweight girls spent more time watching tv ; overweight boys ate a little less frequently ( 4.5 meals a day ) than the normoweight ones ( about 5 meals a day ) ; fewer overweight boys regularly ate breakfast and more overweight students of both genders were on a diet compared with normoweight subjects . more overweight boys and girls had overweight mother and father compared with the normoweight ones . overweight boys and girls showed lower intakes of total energy and macronutrients ( fat , protein and carbohydrates ) than normoweight ones . table 3 reports the mean consumption levels of several food categories in relation to children overweight status . overweight boys reported lower consumption of bread , pasta , salt bakery , milk and yoghurt , sugar - sweetened drinks and sweets , chocolate and jam compared to normoweight ones ; overweight girls reported lower consumption of milk and yoghurt compared to normoweight girls . results of the logistic regression examining the associations between overweight and food consumption habits are presented in table 4 . the tertiles of intake for each food group entered in the model are reported in table 5 . there was a negative association ( p < .05 ) between bread and pasta intake and bmi in boys such that those presenting low and medium level of bread intake were , respectively , 2.76 and 2 times as likely to be overweight than boys presenting high bread intake ; similarly , boys presenting low and medium level of pasta intake were , respectively , 1.83 and 2.45 times as likely to be overweight than those presenting high pasta intake . there was a negative relationship between overweight condition and the intake of salt bakery and milk and yoghurt in both genders such that with decreasing consumption there were greater odds of being overweight ; similarly , with decreasing intake of meat and meat product ( boys only ) , cheese and eggs ( girls only ) , sugar - sweetened drinks , and sweets chocolate and jams ( boys only ) , there were greater odds of being overweight . there was a positive association between the overweight status of students and their parents ' bmi ( table 6 ) , such that boys with a normoweight mother and father were 0.50 times as likely to be overweight than those with overweight parents ; girls with normoweight mother were 0.20 times as likely to be overweight than those with overweight mother , and girls with normoweight father were 0.50 times as likely to be overweight than those having overweight father . there was a negative association between carbohydrates intake and bmi in boys such that those with low intake were 2.5 times as likely to be overweight as those with high intake . no significant associations were found between bmi categories and physical activities , lifestyle characteristics , levels of energy , fat and protein intakes . the results show a high prevalence of overweight and obesity in the group of adolescents studied . in particular , the mean overweight / obese rates were 37% in boys and 31% in girls with a trend to increase with age in boys ( 28% at 11 years and 30% at 1417 years ) and to decrease in girls ( 39% at 11 years and 19% at 1417 years ) . the trend of prevalence of overweight / obesity in roman adolescents reaffirms what other authors have observed in similar population groups [ 38 , 39 ] . however , the prevalence rates are quite high and underscore the need for public health campaigns aimed at preventing and reducing overweight and obesity in roman youth . in this study , overweight status was associated with decreased physical participation ( table 2 ) , highlighting the role that physical activity plays in the childhood obesity epidemic . these results are consistent with the growing body of evidence implicating sedentary activities as one of the leading factors in adolescent overweight [ 40 , 41 ] . moreover , our findings showed also associations for hours of television viewing but for girls only , and for sporting activities outside of school for boys only . strong direct association was also observed between overweight of mother and father and their children , confirming the results of other studies [ 42 , 43 ] . regarding birth weight , hirschler et al . have shown that a high birth weight is linked to a higher risk of becoming obese during childhood , but in our study no relationship was observed between these two variables . as far as breastfeeding is concerned , we did not observe any association with obesity risk reduction ; however , since we did not collect information about the duration of breastfeeding , this could be a limit . nevertheless , on this issue there are contrasting data in the literature [ 45 , 46 ] . we observed in normoweight subjects a more common habit to have breakfast , but the association is statistically significant only for boys . our findings could be in accordance with the growing body of evidence supporting the role of this meal in decreasing body weight . breakfast skipping can lead to overeating later in the day , as it was shown by a study conducted in young healthy men . the result showed the lower frequency of meals consumed associated with the prevalence of overweight status in males , and this agrees with that of other investigators who showed that adolescents with a consistent meal pattern were leaner than those with an inconsistent one . however , this aspect is still controversial [ 50 , 51 ] . in the present study , the percentage of overweight adolescents who stated to be on a diet is high and it is statistically significant ( p < .001 ) when compared with normoweight boys and girls of the same age . we found a negative relationship between energy , macronutrients intakes , and bmi , so that such consumptions were surprisingly higher in normoweight adolescents , than overweight ones , especially in boys . first , although the normal subjects eat more than overweight students , they have also higher physical activity levels with possible consequent higher energy expenditure . second , a significant difference resulted in this study between adolescents being on a diet and not being on a diet ; 29% and 27% , respectively , of overweight boys and girls reported to be on a diet versus only 3 and 7% of the normoweight ones . presumably the subjects on a diet had reduced food consumption during the period of the dietary recall . moreover , as observed in other studies , obese individuals tend to underestimate their food intakes and overestimate their physical activity patterns . possible underreporting of the studied subjects was preliminary assessed using the criteria defined by goldberg et al . . the resting metabolic rate ( rmr ) for each subject was calculated using the prediction equation developed by commission of the european communities   ( rmr[mj / day ] for boys = 0.068  weight [ kg ] + 0.57  height [ m ] + 2.16 ; rmr[mj / day ] for girls = 0.035  weight [ kg ] + 1.95  height [ m ] + 0.84 ) . besides , the mean energy intake was lower in overweight non - underreporting subjects than in normoweight ones . several food groups ' mean intake was lower in overweight / obese than in normoweight non - underreporting subjects showing almost the same results observed in the whole group of subjects . changes in dietary patterns in the past few decades , such as an increase in the consumption of high fat and sugar foods , have been also implicated in the increase in obesity . indeed , in the present study the consumption of food categories or single food items was almost always higher in normoweight boys and girls and it was particularly higher for  milk and yoghurt ( table 3 ) . in this study , a low  milk and yoghurt daily consumption was associated with overweight status ; this result is on line with several epidemiologic studies where an inverse association has been found between milk and dairy consumption and risk of being overweight . there is an increasing body of literature suggesting that dairy calcium may play a role in maintaining stable body weight . intake of sugar - sweetened drinks was lower in overweight adolescents . on this matter , evidence implicating a high intake of soft drinks in promoting weight gain is still controversial . most of our overweight adolescents were on a diet and this could justify the lower consumption of most food items , including sweetened beverages . the multiple logistic regression analyses of food consumption behavior of boys and girls in relation to overweight status confirmed some of the associations found through the analysis of variance . boys with a low / moderate consumption of bread , pasta , meat and meat products , sweets , chocolate and jam show a higher tendency towards overweight status with respect to the subjects with high consumption . in both genders , the tendency towards being overweight grows with decreasing intakes of salt bakery and milk and yoghurt . as previously observed , such trends could be explained with the tendency of overweight subjects to be on a diet . whitaker and colleagues have reported that parental obesity increased the risk of childhood obesity by twofold to threefold at all ages , most likely because the influence of parental obesity is the result of a mixture of genetic and environmental influences . a positive correlation between adiposity of children and parents was observed , confirming the results obtained by the logistic regression analysis ; in particular the tendency towards overweight was 50% lower for students having normoweight father ( both genders ) and mother ( boys only ) with respect to those with overweight parents . in conclusion , the results of this pilot study on adolescents showed a high percentage of overweight / obesity . such nutritional status in both genders was associated with parental obesity , low physical activity level , and being on a diet . the possible consequence of being on a diet is the lower consumption in overweight students of most food groups compared to normal weight subjects . moreover , direct associations were observed between bmi and the more common habit to skip breakfast and a reduced meal frequency ( boys only ) . from the study emerged some critical features related to the dietary profile and lifestyle of the roman normal and overweight adolescents studied . it is our intention to deepen and broaden the investigation in order to provide further data useful for identifying specific and preventive public health actions . d. d'addesa conceived , coordinated , participated in the design of the study and drafted the manuscript . d. martone participated in the design of the study and to the collection of data . l. censi conceived and participated in the design of the study and coordinated the collection of anthropometric data . g. cairella participated in the design of the study and to the selection of the studied subjects .
purpose . to evaluate the relationship between overweight / obesity and dietary / lifestyle factors among italian adolescents . methods . on a total of   756 adolescents with mean age 12.4  0.9 
 , body mass index , food consumption , and time dedicated to after school physical activities and to tv viewing were determined . 
 the data were analysed according to age , nutritional status , and gender . 
 the analysis of variance and multiple logistic regression analysis were performed to investigate the association between dietary / lifestyle factors and overweight / obesity . 
 results . 
 the percentages of overweight and obesity were , respectively , 28% and 9% among boys , 24% and 7% among girls . the overweight / obesity condition in both genders was associated with parental overweight / obesity ( p < .001 
  for mother ) , less time devoted to physical activity ( p < .001 for boys and p < .02 for girls ) and being on a diet ( p < .001 ) . 
 direct associations were also observed between bmi and skipping breakfast and the lower number of meals a day ( boys only ) . conclusions . 
 this pilot study reveals some important dietary and lifestyle behaviour trends among adolescents that assist with identification of specific preventive health actions .