FIZICKA AKTIVNOST ZNACAJAN FAKTOR U SPRECAVANJU GOJAZNOSTI U DECJEl\l UZRASTU

Transcription

1 Med Preg12009; LXII (3-4): Novi Sad: mart-april. 107 Klinika za decje bolesti Banja Luka' Institut za zdravstvenu zastitu majke i deteta, Novi Beograd Originalni naucni rad Original study UDK :613.72] DOl: 1O.2298/MPNS B FIZICKA AKTIVNOST ZNACAJAN FAKTOR U SPRECAVANJU GOJAZNOSTI U DECJEl\l UZRASTU PHYSICAL ACTIVITYASAN IMPORTANT DETERMINANT IN DEVELOPING CHILDHOOD OBESITY Gordana BUKARA-RADUJKOVIC 1 i Dragan ZDRAVKOVIC 2 Sazetak - Istrazivali smo uticaj fizicke aktivnosti. duzine gledanja televizije i rada za kornpjuterorn na indeks telesne rnase dece i adolescenata u regionu Banje Luke. Istrazivanje je obuhvatilo ucenika uzrasta od 6 do 17 godina, 578 decaka i 626 devojcica, Zajedno sa roditeljima ispitanici su popunili anketu 0 fizickoj aktivnosti. duzini gledanja televizijskog programa i duzini rada za kompjuterorn. Utvrdeno je 12.2% umereno gojaznih i 6.1% gojaznih. Pokazan je pozitivan uticaj intenzivne fizicke aktivnosti na normalan indeks telesne mase kod devojcica (p<o.ooi) i decaka (p<o.05). Sedcntarni zivotni sti!. tj. visecasovno gledanje televizije znacajno je povezano sa povisenirn indeksorn telesne mase ked devojcica (p<o.05). Upotreba kornpjutera 2 sata ria dan. povezana je sa povecanirn indeksorn telesne mase kod decaka (p<o.05). Rezultati nase studije dokazuju da su intenzivna fizicka aktivnost i sedentarni iivotni stil znacajne determinante i faktori rizika u razvoju umerene gojaznosti i gojaznosti u detinjstvu. Kljucne rec]: Indeks telesne rnase: Fizicka aktivnost: Gojaznost: Dete: Adolescent: Zivotni stil Summary - The correlation between physical activity and sedentary life style was investigated as a determinant a/the body moss index in children and adolescents in Banjaluka region. The study involved J204 children and adolescents, 6- J7 years old, 578 boys, 626 girls. B:\';[[ was calculatedfrom their height and weight using standardformula. Each child. together with their parents answered the questions considering their level ofinvolvement in physical versus sedentary activities. Physical activity was defined as involvement in sports activities, while sedentary life style was defined as time spent on computer, games, video, and TV The prevalence ofoverweight and obesity were 12.2% and 6. I % in our studv group. Increased physical activity showed strong positive correlation with normal, lower BJ11 in boy's (p<o, (5), and girls (p<ojjo I). Sedentary lifestyle, prolonged T!' watching was strongly associated with increased Blf! only in girls (p: 0.(5). However, computer lise for] hours/day WClS strongly associated with increased B.\;[j (p<o.05) onlv in boys, although computer use for more than 3 hours/day was asssociated with lower BMI in boys Physical activity and sedentary lifestyle are significant determinants ofbmi and risk factors in developing overweight and obesity in childhood, as shown in our study. Key words: Body Mass Index: Excercise: Obesity: Child: Adolescent: Life Style Uvod Gojaznost u decjern uzrastu definisana je kao postojanje viska masnog tkiva u organizmu. U decjem uzrastu sadrzaj telesne masti se menja sa rastom. Kod I 8-godisnjeg mladica iznose oko I8%, a kod devojaka od 20-25%, kod odraslih osoba sa idealnom telesnom masom iznosi 20%. Redovnom i intenzivnom fizickorn aktivnoscu smanjuje se sadrzaj masti u organizmu, a povecava se masa misicnog tkiva. Telesna masa kao i kolicina masti u telu su fizioloski kontrolisane. Gojaznost nastaje kao rezultat neravnoteze izrnedu energetske potrosnje i energetskog unosa. Energetska potrosnja moze da se podeli u tri glavne komponente: energetska potrosnja u mirovanju, fizicka aktivnost i termicki efekti hrane. Vrlo slozeni homeostatski mehanizmi nastoje da odrze ravnotezu izmedu unesene energije (hrane) i utrosene energije potrebne za odrzavanje bazalnog metabolizma, terrnickog delovanja hrane prilikom unosa, probave, termogeneze, telesne aktivnosti i rasta. Telesna masa ce biti konstantna akoje kalorijski unos jednak kalorijskom utrosku energije, ali ako je kroz duze razdoblje ishrana, tj. kalorijski unos neuravnotezeno uvecan, doci ce do povecanja telesne mase. Fizicka aktivnost dece je znacajno smanjena posljednih godina, a energetski unos hrane je previsok Introduction The definition of childhood obesity is the existence of body fat tissue in abundance. In childhood the percentage of body fat is permanently changing along with the growth. In an l S-year-old male the normal body fat percentage is 18%, whi Ie in the 18 y/o female is 20-25%. The adult person, with normal BMI has ideally 20% of body fat. It is known that regular and intensive physical activity decreases the body fat and increases the muscle bulk. The weight and the body fat is physiologically controlled. The cause of the obesity is the result of the disbalance between the energy supply and consumption. Energy consumption involves the basal energy, physical activity and dietary thermal effects. Very complex homeostatic mechanisms are involved in the maintenance of the balance in energy supply and consumption, to maintain the basal metabolism, digestion and dietary thermal effects, physical activity, and growth. The body weight would remain stable if the caloric intake is equal to consumption. The obesity is the result of the imbalance between the two. If the caloric intake is higher than consumption for a prolong period of time.~the body mass/fat will be increased, too. Adresa autora: Mr sc. med. Gordana Bukara-Radujkovic. Klinika za decije bolesii Banja Luka, Cara Dusana 3/3. [-mail: gocabrf(!inccco.net

2 108 Bukara-Radujkovic G, i sar. Fizicka aktivnosti u sprecavauju gojaznosti Skracenice ltlvl - indcks tclcsne mase u odnosu na smanjene aktivnosti. Tokom protekle dye decenije velicina prosecnih porcija hrane se vise nego udvostrucila. Izbor hrane je pod snaznirn uticajem komercijalnih televizijskih programa. Utvrdena je direktna povezanost izmedu prevalencije gojaznosti i prosecnog dnevnog vremena gledanja televizije [1]. To je povezano sa hranom bogatom mastima koju deca jedu gledajuci televiziju. Ipak, nalazi svih epidemioloskih studija ne pokazuju povezanost izmedu unosa masti I ucestalosti gojaznosti kod dece i mladih odraslih osoba. Prevalencija gojaznosti se znacajno uvecala uprkos ociglednom smanj ivanju udela masti u ukupnom kalorijskom unosu. Smanjen un os masti pracen je kornpenzatornim povecanjern potrosnje ugljenih hidrata, posebno u rafinisanom obliku - hleba. cerealija, krompira, zasladenih napitaka, kolaca i biskvita. Zbog brzog porasta potrosnje medu decom zasladeni napici zasluzuju posebnu paznju [2]. Trajna dostupnost hrane kod savremenog coveka rezultuje porastom telesne mase. odnosno gojaznoscu [1]. Slicno kao i u vecini evropskih zemalja i kod nas se zapaza trend promene nacina ishrane i stila zivota (sedentarni), sto se cdrazava i na povecanje gojazne dece, narocito u gradskim sredinama. Istrazivanja upucuju na to da su gojazna deca kandidati i za gojaznost u odraslom dobu. Buduci da je gojaznost dokazani faktor rizika za vise masovnih hronicnih nezaraznih oboljenja, pre svega kardiovaskularuih i dijabetesa melitusa tip 2, vazno je na vreme otkriti decu koja imaju povecanu telesnu masu iii Sll vee gojazna, te provoditi ciljane programe preventivnih mera kao i aktivnosti na promovisanju zdravog nacina zivljenja. Vazno je redovno pratiti stanje uhranjenosti dece i adolescenata, a u slucaju potrebe provodenja rezirna redukcije telesne mase treba angazovati tim strucnjaka, te aktivno ukljuciti i porodicu obolelog. Cilj istrazivanja bio je da se pokaze uticaj fizicke aktivnosti i sedentarnog stila zivota, tj. duzine prosecnog gledanja televizije i rada na kompjuteru na razvoj urnerene gojaznosti i gojaznosti kod dece i adolescenata u regionu Banje Luke. Materijal i metode Studija je obuhvatila ucenika od 6 do 17 godina u regij i Banje Luke. Ispitivano je 578 decaka prosecnog uzrasta 11 godina 7 meseci i 626 devojcica prosecnog uzrasta I 1,5 godina. Ispitivanje je obavljeno u februaru godine na zdravoj deci osnovne skole i Medicinske sko]e iz Banje Luke, kao i u seoskoj osnovnoj skoli Sargovac u blizini Banje Luke. Telesna masa je merena sa greskom od 500 grama upotrebljavajuci standardnu elektronsku vagu. Telesna visina je merena sa greskorn od 0,5 cm. U toku merenja sva deca su bila u donjern rublju. Indeks telesne mase izracunat je iz odnosa telesne mase i kvadrata telesne visine (ITM= kg/m). Abbreviations 8M! - body mass index Over the last two decades. physical activity in children has been decreasing. while the dietar. intake and sedentary lifestyle has been increasing. The children's meal portion is doubled. as well as time spent in front of TV. Furthermore the choice of children's meals is under the high influence of the TV commercials. The direct 'Correlation between the prevalence of the obesity and the time spent in front of TV has been shown in the study of Beunen [1]. He states that dietary high fat is the main reason. although the other epidemiological studies did not agree with that. The prevalence of the obesity has significantly increased despite the decrease in the fat percentage in the total calory intake. The decreased intake of fat is associated with the compensatory increase of carbohydrate intake. especially in refined forms of bread, cereals, potatoes, sweeten drinks. cookies. and biscuits. The consumption of sweeten drinks, sodas is significantly increasing, therefore they are of the particular interest [2]. In our country, as in most European countries. a new trend of changing lifestyle and eating habits is noticeable too. which results in increasinz obcsitv among children especially in urban areas~ Obesity in childhood is the predisposing factor for the obesitv in adults. Obesity is the confirmed risk factor foi~ the multiple chronic diseases. as cardiovascular diseases. diabetes mellitus type 2. Therefore it is important to detect the obesity in childhood and act/treat/make special programs with preventive activities ancl promote the healthy lifestyle in order to prevent obesity and chronic diseases. It is important to follow up BMI in children and adolescence. and treat the obese child using a special individualized program. which should involve the specialist and the child's family. This study was structured to compare the effects of physical activity and sedentary life style. i.e. time spent in front of TV, computer lise/pial' on the development of overweight and obesity in children and adolescents in Banjaluka region, Bosnia and Herzegovina. Material and methods The studv involved 1204 children and adolescents, 6-17 years old, in Banjaluka region. There were 578 boys, mean age 11 yrs and 7 months. and 626 girls, mean age 1 I yrs and 5 months. The stud) was done in Februarv It involved the children in elementary school' in the urban part and suburb of Banjaluka. The body weight was measured to the nearest 0.5 kg, using a standard beam balance scale. The body hc~ght V\~1S measured to the nearest 0.5 cm. During the measurement the subjects were in their underwear without shoes. The bodv mass index. was calculated as the ratio of body' weight to

3 Med Pregl 2009; LXII (3-4): Novi Sad: mart-april. 109 Gojaznost smo detlnisali kao indeks telesne mase iznad 95. percentila za odgovarajuci uzrast i pol, a indeks telesne mase izmedu 85. i 95. pecentila kao umerenu gojaznost. Indeks telesne mase (ltm) prikazan je u vidu percentilne distribucije u poredenju sa NCHS/SZO referentnim vrednostima i kriterijumima. Sva ispitivana deca i njihovi roditelji ucestvovali su dobrovoljno u anketi koja je sadrzavala pitanja 0 fizickoj aktivnosti i sedanternorn stilu zivota. Sedentarni stil zivota bio je definisan vremenom provedenim ispred TV i kompjutera u satima: I sat, 2, 3, 4, 5 i vise sati. Fizicka aktivnost deteta je definisana upraznjavanjern sportske aktivnosti, I. po malo i retko, 2. povremeno i 3. cesto i redovno. Statisticke metode Dobijeni podaci su zapisani u okviru kompjuterskog statistickog programa za obradu podataka (SPSS Windows 2000). Rezultati su izrazeni kao aritmeticka sredina sa pripadajucom standardnom devijacijom. Standardna devijacija i koeficijent varijacije racunati su za telesnu visinu, tezinu i ITM za sve uzraste od 6 do 17 godina, za rnuske, i zenske ispitanike, odvojeno. Statisticka znacajnost razlike srednje vrednosti odredivana je Studentovim t testom iii Man-Whitney testom. Za procenu stepena povezanosti dvaju parametara izra- cunat je koeficijent korelacije iii regresiona kriva. Rezultati Od svih ispitanika zabelezeno je 12,2% umereno gojaznih i 6, I% gojaznih. Jedino je kod devojcica pronadena znacajna povezanost izmedu visecasovnog gledanja televizije i stepena gojaznosti (p<0,05). Devojcice koje su pred televizijom provodile I sat imale su znacajno manji ITM od devojcica koje su pred televizijom provodile 4 i vise sati (Tabela 1). Nije nadena znacajna povezanost porasta ITM sa satima provedenim pred televizijom kod djecaka. Svi decaci koji su pred televizijom provodili I, 2, 3 sata imali su priblizno jednak ITM. Decaci koji su provodili 4 sata i vise pred TV imali su najveci ITM. Odnos vremena provedenog za kompj uterom i gojaznosti pokazao je da gotovo 50% ucenika n~ma vlastiti kompjuter kod kuce, sto je moglo uticati na dobijene rezultate. Upotreba kompjutera 2 sata na dan, povezana je sa povecanirn ITM jedino kod decaka (p<0,05). Indeks telesne mase decaka koji ne koriste kompjuter znacajno je nizi od ITM decaka koj i provode dva sata pred kompjuterom. Znacajno je napomenuti da tri i vise sati provedenih pred kompjuterom dovode do smanjenja ITM. Kod devojcica nije pronadena povezanost gojaznosti i vremena provedenog pred kompjuterom (Tabela.1). Pokazan je pozitivan uticaj intenzivne fizicke aktivnosti na normalan ITM kod devojcica (p<o,ooi) I decaka (p<0,05). Kod decaka je pronadeno da postoji znacajna razlika ITM u grupi onih koji se retko bave sportom u odnosu na grupu decaka koja se povremeno bave sportom (p<0,05). Decaci koj I se Tabela 1. Povezanost indeksa telesnc rnase ucenika sa duzinom pracenja televizije, rada na kornpjuteru. fizickorn aktivnosti Table I. Correlation of children's B\II with physical activitv, hours o(ti' watching and computer working Sati pred televizijorn n' ll'utchll1g hours 2. ::; sata/fumr.\' 3" sataj!w/l1".\ 4 4 sataj/wl!/'.\ :' S satilho"n Sati pred kompjuterom. ( 'ompnter working hours I 0 sati/holl! :: I sati//um!".' 3. :: hiluml's 121 IS.403,D 17, ,2,,3,0 17< 1",9 127 IS,D/d , :1:2,9 17, :::: ,7 0,0< NZ/l\S ')S I'J, 1,3,8 IS,i-I q hiviselho/lrsuljdlllol'e 41 IS,I±_l,1 17,1-19,1 Fizicka sportska aktivnost IT'd djecakaih:\/i III hll'., broj x± SD l):io'oly IT\I djch)lcie"ih\//:1/ g"i, 21 19,}.±.3A 17,7-20,9 IJhYSIL-'llluclll'I~~ 53 18,C):;:"--t.S J7,6-:U.3 7 l ) 20:1;.1.4 J\)-:I I. retku/sddof11 0.0:' -(ruu I 3 C"SlO/otlc'lI 282 IS 113,3 17.S-18, ,8 17,~-ISI x - aritrneticka sredina. SO - standardna devijacria. CV - kocficiicm vanjacije p- verovat- 1l0caim - I11t'(OI,.\J) - standard dcviatnnt. ('/ - c(}t~!ficlt'!i{ II1 auallon n-numher. JI cnrrclution«is.\lgm!/cwii at th«o,(}()j(().(j5j lcve! to body height square (kg/m). Assesment of chil~hood overweight was based on the standard definition for 8MI and the IOTF (International Obesity Task Force)-recomended cut-off criteria for overweight (which includes obesity) described by Cole et al. [3]. In our study, we used age and gender 8MI values for children and adolescents corresponding to 8MI values of 25 and 30 kg/me at age 18 for defining overweight and obesity. respectively, in children and adolescents aged 2-18 years [3J. The youth with 8MI values corresponding to an adult 8MI of<25.0 kg/me were classified as normal weight and the youth with 8MI values corresponding to an adult 8MI=25 kg/rn" were classified as overweight. 8MI=30 kg/me corresponding to obese groups [3J. All children together with their parents gave their informed consent for voluntary questionnaire about weight, physical activity and sedentary lifestyle. Sedentary lifestyle was defined as time spent on TV, computer/games in hours: 1, 2, 3, 4, 5 and more hours. Physical activity was defined as quantitative involvement in sports activities, l-none and/or rare, 2- seldom and irregularly. 3 often and regularly. Statistical analysis Data management and computation of descriptive statistic and prevalence were performed using SPSS software (v 12.0 for Windows 2000). All variables of the study were found to fit normal

4 110 Bukara-Radujkovic G, i sar. Fizicka aktivnosti u sprecavanju gojaznosti uopste ne bave sportom imaju interesantno manji ITM od decaka koj i se povremeno bave sportom. Najmanji ITM imaju decaci koji se cesto bave sportom (Tabela 1). Kod devojcica fizicka aktivnost je jos znacajnije povezana sa gojaznoscu (p<o,oo 1). Devojcice koje se uopste ne bave fizickom aktivnoscu imaju najvec: ITM, za razliku od devojcica koje se povremeno bave fizickorn aktivnoscu. Naj lakse su devojcice koje se cesto bave sportom (Tabela 1). Diskusija Dosadasnje studije su potvrdile znacajnu povezanost duzine pracenja televizije i gojaznosti dece i adolescenata [1]. Interesantani su rezultati dobijeni poredenjem indeksa telesne mase i duzine gledanja televizije. Jedino je kod devojcica pronadena znacajna povezanost duzine gledanja televizije i gojaznosti «0,05). Devojcice koje su pred televizorom provodile samo jedan sat imale su znacajno manji ITM od devojcica koje su pred televizorom provodile 4 sata i vise. Decaci koji su provodili pred televizorom jedan, dva, tri sata imali su priblizno jednak ITM. Decaci koji su provodili pred televizorom cetiri sata i vise imali su znacajno veci ITM. Danasnje generacije dece provode i po nekoliko sati na dan gledajuci televiziju, sto utice ne samo na smanjenje nj ihove fizicke aktivnosti, cime se povecava rizik za gojaznost, nego i na kvalitet prehrane. Serra i saradnici su, na bazi ispitjvanja prehrambenih i zivotnih navika kod dece u Spaniji i adolescenata uzrasta od 2 do 24 godine, procenili da gledanje televizije oko 2 sata na dan povecava "prehrambeni rizik" (hrana visoko energetska - grickalice) za 37%. a posebno je uoclj iv nedovoljan dnevni unos vitamina i minerala [3]. U velikom broju studija je pronadena pozitivna korelacija izmedu sati provedenih u gledanju televizije i gojaznosti. Postoje i studije sa suprotnim rezultatima [4,5]. U studij i koja je obuhvatila dece, uzrasta 6 do 11 godina i adolescenata uzrasta od 12 do 17 godina pronadcna je znacajna korelacija izrnedu sati provedenih pred televizorom i povecanja ITM [6-8]. Kod adolescenata je zabelezen porast prevalencije gojaznosti za 2% za svaki dodatni sat gledanja televizije [9]. Suprotno ovome nije naden porast ITM sa duzinorn gledanja televizije kod decaka adolescenata [10]. Prema istrazivanju Nielsen kompanije procena je da americka deca uzrasta od 6 do 11 godina gledaj u u proseku vise od 23 sata televiziju nedeljno, i uzrasta 12 do 17 godina gledaju u proseku 21 sat nedeljno. Iz iznetog, proiz.ilazi zakljucak da odnos izmedu gojaznosti i gledanja televizije moze biti rezultat porasta energetskog unosa, iii konzumiranja hrane u toku gledanja televizije iii rezultat reklamiranja hrane iii smanjenje potrosnje energije, odnosno smanjenje fizicke aktivnosti [9]. Nasa anketa u vezi sa korelacijom gojaznosti i sati provedenih pred kompjuterom takode Je dala interesantne rezultate. Vise od 50% ucenika jos nema vlastiti kompjuter. Kompjuter su cesce koristili dedistribution. Means. standard deviation scores (m±sd) and coefficient of variation scores were calculated for height, weight and 8MI for each year for the 6 to 17 year age groups. A P-value of 0.05 was used to determine significance. Results Among 1204 subjects. we found 12.2% overweight and 6.1 obese chi ldrcn. There was significant correlation between girls' obesitv and sedentary lifestyle. i.e. time spent in front ot' TV (p<o.05). The girls with lower 8MI spent only I hour in front of TV, while the girls who spent more than 4 hours in front of TV had a significantly higher 8MI (Table 1). In male group there was no such correlation. No significant difference was found in 8MI in boys that spent 1, 2, 3 hours in front of TV, although the boys that watched TV more than 4 hours had the highest 8M!. Computer use for more than 2 hours was strongly associated with increased 8M!. onlv in bovs (p<0.05). although computer use for more than - 3 hours/day was associated with lower 8M!. In the female group there was no correlation between computer use and obesity. Half of involved chi Idren had a personal computer. Increased physical activity showed a strong positive correlation with a normal, lower 8MI in boys (p<0.05), and girls (P<O.OO l). There was a significant difference in between the boys who were involved in physical activities in group 1 (rare) and 2 (seldom) (p<0.05). The lowest/ normal 8Ml was found in the boys involved in rezular sports activities (Table I). - Female obesity is strongly associated with physical activity (p<o.oo 1). The girls involved in regular physical activities had the lowest/normal 8MI, compared to the girls involved in irregular physical activities. The girls with no physical activities had the highest 8MI (Table I). Discusion Almost all previous studies have shown a significant correlation between obesity and sedentary lifestyle, that is usually defined prolonged TV viewing and/or time spent in front of computer [1]. Nowadays. children and adolescents spend more time in front of TV and/or computer that results in significantly decreased involvement in physical activity. Furthermore. prolonged TV viewing usually includes constant snacking at the cost of normal d ietary intake. These factors significantly increase the risk of obesity. Serra et al shown in their study that the risk of dietary fat intake is increased to 37% of daily caloric intake in Spanish children and adolescent who are in front of TV for 2 hours. not to men

5 Med Pregl 2009; LXII (3-4): Novi Sad: mart-april. 111 caci. Mozda je to i razlog da smo nasli znacajnu pozitivnu korelaciju povisenog ITM sa satima provedenim pred kompjuterom jedino kod dec aka (p<0,05). Indeks telesne mase decaka, koji su pred kompjuterom provodili jedan sat, bio je znacajno nizi od ITM decaka koji su pred kompjuterom I?rovodili dva sata. Znacajno je napomenuti da decaci koji pred kompjuterom provode tri sata i vise su imali manji ITM u odnosu na decake koji su pred kompjuterom provodili do dva sata, ali i dalje su imali visi ITM u odnosu na decake koji uopste nisu koristili kompjuter. Ova zabelezena razlika ITM zavisno od duzine sati pred kompjuterom moze se objasniti time kako je za rad na racunaru neophodno koristenje ruku, sto onernogucava istovremeno uzimanje hrane. Takode, ne sme se zaboraviti i potrosnja energije za intelektualni rad. Treba skrenuti paznju kako koristenje kompjutera u kontinuitetu duze od 3 sata, sigumo oriernogucuje kvalitetnu ishranu i dovoljnu fizicku aktivnost u toku dana. Kod devojcica nismo pronasli povezanost ITM i sati provedenih u radu racunarorn. Moguci razlog takvih rezultata je to sto vee ina devojcica provodi najvise jedan sat pred kompjuterom. Fizicka aktivnost je vazan regulator telesne mase. Fizicka aktivnost je najprirodniji nacin trosenja energije, koja je u razvijenim zemljama zbog tehnoloskog napretka postala vrlo ogranicena. Rezultati istrazivanja 0 uticaju fizicke aktivnosti na telesnu masu su razliciti. Svima im je zajednicko da je redovna fizicka aktivnost kod oba pola povezana sa manjim postotkom masnoce u ukupnom telesnom sastavu. Razlike u kolicini masnoca u telu medu fizicki aktivnim i fizicki neaktivnim vece su kod devojcica nego kod decaka [12]. Intenzivniji procesi fizickih aktivnosti uticu na promene u nemasnom delu tela. Treba naglasiti specificnost uticaja razlicitih vrsta intenzivnijih fizickih aktivnosti. Misicna hipertrofija je primamo povezana sa treninzima snage. Mehanicka opterecenja uticu na modeliranje kostiju, a fizicka aktivnost povecava gustinu kostiju. Redovna fizicka akivnost dece dovodi do bolje kondicije/aerobne izdrzljivosti i viseg nivoa funkcionalno-motorickih sposobnosti (posebno misicne izdrzljivosti i brzine trcanja) [I]. Motoricke sposobnosti se s odrastanjem povecavaju. Devojcice postizu "plato" motoricke sposobnosti oko 14. godme, a decaci koju godinu kasnije. Deca mlada od 10 godina, nezavisno od pola, vrlo malo poboljsavaju svoju kondicionu/aerobnu sposobnost pod uticajem treninga. Ne preporucuju se vezbe snage moci pre puberteta jer postoji velika opasnost od povreda. Uticaj fizicke aktivnosti na regulaciju telesne mase i funkcionalno-rnotoricku sl?osobnost dece je evidentan te je veoma vazna fizicka aktivnost dece i omladine, prvenstveno za razvoj pozitivnog odnosa i navika redovnih fizickih aktivnosti kao i za razvoj motorickih i funkcionalnih sposobnosti. Pri vrednovanju uticaja fizicke aktivnosti na ITM treba napomenuti da kod devojcica u vreme puberteta postoji yoveeanje kolicine i procenta masnog tkiva, kod decaka smanjenje lipoproteina visoke gustoce, kod oba pola povisenje krvnog pritiska i smanjenje osetljivosti na insulin. Istrazivanja fizicke aktivnosti tion the insufficient intake of vitamins and minerals [3]. A largest study that involved 6965 children, 6-11 years old, and 6671 adolescents, years old showed the direct correlation between obesity and TV watching. According to the Nielsen's study, the American children 6-11' years old spend on average more than 23 hours per week, while the adolescents years old spend 21 hours per week [9]. They speculated that obesity is caused by the increase of total caloric dietary intake as well as decreased physical activity during prolonged TV watching. In adolescents, every 1 hour of TV watching increases the obesity prevalence by 2% [9]. Contrary, there are only a few studies that have not found such a correlation between obesity and sedentary lifestyle. In our study, the significant correlation of obesity and prolonged TV watching was found only in girls (p<0.05), although the boys watching TV for more than 4 hrs had the highest 8M!. Computer use for 2 hours was associated with obesity only in boys (p<0.05), and not in girls. This is most likely because in our study only 50% of subjects had their own personal computer at home, and boys were using computer more than the girls, who usually spent only 1 hr in front of computer. The boys using computer for more than 3 hours per day had lower 8MI than the boys that spent 1-2 hrs. This can be explained by the fact that the computer use requires both hands and active motor interaction. Physical activity is the most natural way of energy consumption and an important regulator of body mass. Regular physical activity is associated with a lower fat percentage in both genders. However, the higher percentage of body fat is found in physically inactive girls than in physically inactive boys [12]. Hormonal changes in puberty furthermore increase fat percentage in girls, while decreasing the HDL in boys. Regular physical activity in children results in better aerobic capacity, a higher level ofmotor functioning especially fast running and better endurance [I]. Motor functioning increases along with the growth. Girls reach the maximum of their motor functioning at the age of 14, and boys a few years later. Children younger than 10 years, regardless of gender can increase their aerobic capacity very little during an intensive physical activity. Therefore, a powerful intense physical activity/training is not recommended before puberty because of a high risk ofsports injury. Studies ofphysical activity in European and American children and adolescents showed the increase in physical activity by early adojescence and significant decline thereafter. This de ~!ine is more prominent in boys than in girls,

6 112 Bukara-Radujkovic G, i sar. Fizicka aktivnosti u sprecavanju gojaznosti evropske i severnoarnericke dece i omladine poka-.zala su da se aktivnost skolske dece povecava do rane adolesccncije, kad pocinje opasno da se smanjuje. To smanjivanje fizicke aktivnosti u fazi kasne adolescencije izrazenije kod decaka nego kod devojcica, mada su decaci fizicki aktivniji od devojcica [1 1]. U nasoj studiji pokazan je pozitivan uticaj intenzivne fizicke aktivnosti na normalan ITM kod devojcica (p<o,oo1) i decaka (p<0,05). Decaci koj i se uopste ne bave sportom imaju manji ITM od decaka koji se povremeno bave sportom. Najmanji ITM su imali decaci koji su se cesto bavili sportom iii bili aktivno ukljuceni u sportske klubove. U nasoj anketi zabelezili smo pozitivan uticaj redovne (najmanje 3 puta sedmicno po 1 sat) fizicke aktivnosti na normalan ITM decaka. Najveci indeks telesne mase imale su devojcice koje se ne bave fizickom aktivnoscu, Devolcice koje su se povremeno bavile fizickorn aktivnoscu imale su manji ITM od devojcica koje se uopste nisu bavile fizickorn aktivnoscu, ali veci ITM su imale od devojcica koje su se cesto bavile fizickorn aktivnoscu. Najmanji ITM (odnosno norrnalnu telesne masu), imale su devojcice koje su cesto fizicki bile aktivne. Objavljeni su i brojni radovi u kojima nije pronadena korelacija izmedu gojaznosti i fizicke aktivnosti kod decaka iii devojcica [12]. U literaturi, ['0 eravilu, gojazna deca manje ucestvuju u snaznirn fizickim akfivnostima i umerenim vezbama. Oni su manje u formi od mrsavih. Go~azni cdrzavaju svoju telesnu masu neaktivnoscu 11-,]. Huttunen i saradnici su pronasli razliku u duzini vremena koje mrsavi i debeli provode u fizickirn aktivnostima [14]. Ovi rezultati su slicni nasim rezultatima. Gojazna deca su rede clanovi zvanicnih sportskih klubova od normalno uhranjene dece. Iz navedenih istrazivanja moze se zakljuciti da je fizicka aktivnost veoma vazan faktor u prevencij i gojaznosti i odrzavanju normalne telesne mase. Zakljucak Pokazan je pozitivan uticaj intenzivne i redovne fizicke aktivnosti na normalan indeks telesne mase kod devojcica (p<o,oo I) i decaka (p<0.05). Najmanji indeks telesne mase imaju devojcice koje se cesto bave sportom. Najmanji indeks telesne mase medu decacima imaju oni decaci koji se uopste ne bave sportorn. Oni decaci koji se cesto bave sportom imaju dobro razvijenu misicnu masu i spadaju u grupu decaka sa normalnom telesnom masom. Sedentarni zivotni stil, tj. visecasovno gledanje televizije, bilo je znacajno povezano sa povisenim indeksom telesne mase jedino kod devojcica (p<0,05). Upotreba kompjutera 2 sata na dan, povezana Je sa povecanim indeksom telesne mase jedino kod decaka (p<0,05). Decaci koj i koriste kompjuter 3 sata i vise postaju laksi od decaka koji koriste kompjuter 2 sata, ali su i dalje tezi od decaka koji uopste ne koriste kompjuter. Rezultati nase studije dokazaju da su smanjena fizicka aktivnost i sedentarni zivotni stil, znacajne determinante i faktori rizika u razvoju umerene gojaznosti i gojaznosti u detinjstvu. although boys in general are more physically active than girls [11]. In our study, we found the significant positive correlation between physical activity and obesity in girls (p<0.001), and boys (p<0.05). The lowest/normal 8MI was in boys who were involved in regular and intense physical activity (at least I hour duration three times per week). These boys had well developed muscle mass and normal 8MI. Contrary, the lowest 8MI was found in inactive boys who were malnourished with atrophic muscles for their age. Hunter et al showed similar results [14]. The highest 8MI was found in physically inactive girls, while the girls who went in for a regular physical activity had the lowest/normal 8MI. Obese children, in general maintain their weight by decreased or no physical activity [13]. Obese children are less frequently members of an official sports' association and participants at a competition than children with normal 8MI. All these results suggest that physical activity is an important factor in prevention ofoverweight and obesity in children and adolescents. In addition, decreasing or controlling time spent in front ofty and computer, as well as balanced dietary intake can promote healthy lifestyle from childhood to adolescence. Conclusion Regular physical actrvrty correlates positively and strongly with normal 8MI in girls (p<o.oo I) and boys (p<0.05). The lowest/normal 8MI was found in girls involved in regular physical activity. Similarly, boys involved in regular sports activities have well developed muscle mass and normal 8MI. Sedentary lifestyle, prolonged TV viewing (more than 4 hi's) correlates positively and strongly with the obesity only in girls (p<0.05). Computer use for 2 hi's per day was associated with obesity only in boys (p<0.05). This is probably significant only for our study since only 50% of subjects had a personal computer and boys were using computer more often and longer than girls. Results of our study have shown that sedentary Iifestyle and decreased physical activity are important risk factors for developing overweight and obesity in children and adolescents.

7 Med Pregl 2009; LXII (3-4): Novi Sad: mart-april. 113 Literatura I. Beunen G, Malina R, Renson R, Simons J. Ostyn M. Lefevre J. Physical activity and growth, maturation and performance: a longitudinal study. Med Sci Sports Exerc 1992;24: Mokdad AH. Serdula MK, Dietz WHo Bowman BA. Marks JS, Koplan JP. The continuing epidemic of obesity in the United States. JAMA 2000:284: Serra-Majern L. Ribas L. Perez-Rodrigo C. Garcia-Closas R, Pena-Quintana L, Aranceta J. Determinants ofnutrient intake among children and adolescents: results from the enkid study. Ann Nutr Metab 2002:46: Armstrong CA, Sallis JF, Alcaraz JE, Kolody B, McKenzie TL, Hovell MF. Children's television viewing, body fat and physical fitness. Am J Health Pro mot 1998; 12: Myers L, Strikrniller PK, Webber LS, Berenson GS. Physical and sedentary activity in school children grades 5-8: The Bogalusa Heart Study. Med Sci Sports Exerc 1996;28: Andersen RE, Crespo CJ, Bartlett SJ, Cheskin LJ, Pratt M. Relationship of physical activity and television watching with body weight and level of fatness among children: results from the Third National Health and Nutrition Examination Survey. JAMA 1998:279: Robinson TN, Killen JD. Ethnic and gender differences in the relationships between television viewing and obesity. physical activity. and dietary fat intake. J Health Educ 1995:26: S91-S Obarzanek E, Schreiber GB. Crawford PB, Goldman SR, Barrier BM, Frederick MM, et a!. Energy intake and physical activity in relation to indexes of body fat: the National Heart. Lung, and Blood Institute Growth and Health Study. Am J Clin Nutr 1994;60: Dietz WH, Gortmaker SL. Do we fatten our children at the television set? Obesity and television viewing in children and adolescents. Pediatrics 1985;75: Rad je primljen 23. VIII Prihvacen za stampu 29. IX BIBLID :(2009):LXII:3-4: Tucker LA. The relationship of television viewing to physical fitness and obesity. Adolescence 1986:21 : Malina RM, Bouchard C. Growth. maturation and physical activity. Champaign. IL: Human Kinetics: Krassas GE. Tzotrzas TH, Tsametis C. Konstantinidis T. Prevalence and trends in overweight and obesity. among children and adolescents in Thessaloniki. Greece. J Pediatr Endocrinol Metab 200 I: 14(Suppl 5): Fogelholm M, Nuutinen O. Pasanen M, Myohanen E. Saatela T. Parent-child relationship of physical activity patterns and obesity. Int JObes Relat Metab Disord 1999;23: Huttenen NP, Knip M, Paavilainen T. Physical activity and fitness in obese children. Int JObes Relat Metab Disord 1986; I0: Maffeis C, Zaffanello M. Schutz Y. Relationship between physical inactivity and adiposity in prepubertal boys. J Pediatr 1997; I31 : Birch LL, Fisher JO. Development of eating behaviors among children and adolescents. Pediatrics 1998; 10 I(Suppl): Bouchard C. Current understanding of the etiology of obesity: genetic and nongenetic factors. Am J Clin Nutr 199 J; 53:156IS. 18. Fidanza F. Nutritional status assessment. London: Chapman and Hall; 1992: Gortmaker SL. Dietz WH. Sobol AM. Wehler CA. Increasing pediatric obesity in the United States. Am J Dis Child 1987;141: James PT, Leach R. Kalamara E. Shayeghi M. The worldwide obesity epidemic. Obes Res 2001 ;9:228S-33S. 2 I. Krassas GE. Tzotzas T, Tsametis C, Konstantinidis T. Determinants of body mass index in Greek children and adolescents. J Pediatr Endocrinol Metab 2001:14(Suppl 5):