moi lien quan gi^ta nang luong va phan tram

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TC.DD&TP10(2)-2Q14 MOI LIEN QUAN GI^TA NANG L U O N G VA PHAN TRAM

NANG LlTdNG Ttf CAC CHAT DINH DTTSNG V 6 I BMI:

NGHIEN CUtJ THUAN TAP THlTC HIEN TREN HOC SINH TRUNG HOC Cd s 6 THANH PHO HO CHI MINH

Nguyen Hoang Hanh Doan Trang', Tdng Kim Hdng' Muc tieu:Danh gia sir thay doi cua nang luong va cac chat dinh duong trong khau phan an a hoc sinh trung hgc ca sa (THCS) TPHCM trong 5 nam va m6i Hen quan voi BMI.

Phircng phap: Mot nghien cuu thuan tap dugc thuc hien trong 2004-2009. BMI, thai gian danh cho boat dgng the luc, xem TV va cac chat dinh duong an vao duoc khao sat hang nam tren 759 hoc sinh THCS. Muc do tuong quan giua nang lugng, chSt dinh duong trong khau phan an cua nam 1 va nam thir 5 dugc danh gia bang he s6 Spearman va chi so Kappa. Mo hinh GLLAM dugc dung de khao sat moi lien quan giua nang lugng va phan tram nang lugng tu protein, glucid va chdt beo voi BMI. Ket qua: Theo doi sir thay doi d tijng ca nhan qua 5 nam chiing toi thay su tuong quan thap nhat la phan tram nang lugng tir glucid va protein, cao nhat la lugng chat beo an vao (he so tuong quan va chi so Kappa la 0,38 & 0,29 doi voi nam, va 0,29 & 0,27 doi vai nG). Mo hinh tuyen tinh da tang cho thay khong co bien so dinh duong nao lien quan co y nghTa voi BMI vi chi so BMI con phu thugc vao tieu hao nang lugng va thoi gian ng6i ttnh tai (dugc trinh bay trong mgt bao cao khac). Ket luan: Su thay doi lugng chat dinh duong an vao rat dao dgng cho thay rang viec can cu vao tinh hinh dinh duong ca nhan trong nam dau kho co the tien doan dugc nang lugng va chat dinh dudng trong khau phan an sau 5 nam o hgc sinh THCS.

Tir kfaoa: BMI, chdt dinh duang, ndng luong, tre vi thdnh nien I- D ^ T VAN D E

Nhihig nam gan day, ty le thira can- beo phi a tre em va tre vi thanh nien TPHCM tang dang kk. Tir nam 2002 dkn 2004, ty le thua can tang gap doi: tu 5,0% 16n 11,7% trong khi ty le beo phi tang g i p ba: th 0,8% d i n 2,0% [1]. Nhieu nghien cihi da cho thay r3ng beo phi 6 tre vi thanh nien lam tang nguy c a beo phi o nguai Ion [2]. Vi vay, can co khao sat de hieu va ngan ngira thua can va beo phi a tre vi thanh nien va lam han che sir gia tang thira can va beo phi o nguoi Ion trong nhi^u nam sap toi.

Vi thanh nien la giai doan ma nhimg

hanh vi an uong co the co anh huong rat Ion len su beo phi o giai doan truong thanh va len kha nang mac benh man tinh trong nhirng nam ve sau. Vi thanh phan cac chat dinh duong nhu chat beo, protein CO the dong vai tro quan trgng trong sir beo phi o tre em, chiing ta nen thuc hien viec danh gia lugng chat dinh duong trong khau phan an tu tuoi vi thanh niSn d8n tuoi day thi de xem viec duy tri tuang doi cac chat dinh duong trong khdu phan an anh huong the nao den hanh vi an uong theo thoi gian vi che do an uong dugc hinh thanh trong giai doan dau doi co the anh huong den su tien ' TS.BS - D?i hoc Y khoa Pham Nggc Thach

Email: [email protected] 2 TS.BS - Dai hoc Y khoa Pham Nggc Thach

Ngay giri bai: 20/6/2014 Ngay phan bien nhan xet: 15/7/2014 Ngay dang bai: 25/7/2014

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TP n n & T P 1 0 f 2 ) - 2 0 1 4 triln ciia benh man tinh. Cho den nay, co

mot s6 nghien cuu theo doi dgc da khao sat muc do duy tri lugng chdt dinh duong an vao tir do tu6i vi thanh nien den do tu6i day thi nhung cho kk qua kh6ng gidng nhau. Hon nGa, chiing ta deu biSt beo phi la do su mdt can bang giira nang lugng an vao va nang lugng tieu hao [3], do do cdn phai danh gia moi Henquan giiia nang lugng toan phan va phan tram nang lugng tit cac chat dinh duong nhu protein, bgt duong va chdt beo voi tinh trang beo phi 6 tre vi thanh nien. Nhieu nghien cuu da dugc thuc hien de danh gia m6i lien quan nay nhimg ket qua khong th6ng nhat va hau het thiet ke nghien cuu la cdt ngang [4-7], Trong bai bao nay, chiing toi danh gia sir duy tri nang lugng va chat dinh duong trong khdu phdn ana hgc sinh trung hgc co so (THCS) trong mgt nghien cuu thuan tap 5 nam tai TPHCM va khao sat moi lien quan giita nang lugng va phan tram nSng lugng tir cac chat dinh duong vol BMI 6 cac em nay.

II. DOI TlTONG VA PHirONG PHAP Ddi tuang nghien cuu

Mgt nghien ciiru thuan tap 5 nam dugc thuc hien tir nam 2004 din 2009, voi mau dugc nit ra tir nghien ciju cat ngang (dimg ky thuat chgn mlu cum nhieu giai doan theo phuong phap PPS de khao sat tinh trang thua can-beo phi va cac hanh vi CO lien quan voi thira can-beo phi) o hgc sinh THCS TPHCM vao nam 2004.

Tir 31 trudng dugc chgn trong nghien cuu cat ngang, chimg toi su dung phuong phap chgn ngau nhien he thong de chgn ra 18 truong. Trong moi truong, chgn mgt lap thugc kh6i 6-7. Co 759/784 hgc sinh dong y tham gia nghien cuu doan

he. Chi tiet vk nghien cuu nay da dugc cong bo truac day[8].

Thu thdp so lieu

CJ m6i idn thu thap s6 lieu hang nam, chiing toi do cac s6 do nhan trac cimg vdi cac ykn tk tilp xiic. Chieu cao hgc sinh dugc do bdng thuoc do chiiu cao dung (Microtoise) va can nang hgc sinh dugc do bang can dien tii (Tanita). Cac chat dinh duong trong khau phan an va hanh vi an u6ng dugc danh gia qua bang cau hoi (BCH) tdn sudt tieu thu thuc pham d5 dugc kilm dinh [9]. BCH nay bao g6m nhiing cau hoi ve tan suat tieu thu ciia 160 mon an trong 6 thang qua. Nang lugng toan phan va thanh phSn protein, glucid,chdt beo trong cac thuc phSm dugc tinh bdng phan mem EIYOKUN v.l[10]. T6ng lugng chat dinh duong trong khau phan an hang ngay dugc tinh bdng each lay tdng gia tri rieng le tir tan sudt thuc an tieu thu nhan voi gia tri trung binh cua lugng an vao va lugng chdt dinh duong cho moi lOOg. Chiing toi loai nhirng truong hgp co nang lugng hdp thu khong hgp ly (<500kcal/ngay hoac >5000kcal/ngay) theo khuyen cao cuaRocket[ll].

Xicly so lieu

Kit qua dugc trinh bay voi trung binh

± do lech chudn nlu dii' lieu phan ph6i binh thuang. Do hau het cac phan phoi chat dinh duong bj lech phai ve phia gia tri cao hon, nen cac phan phoi nay dugc trinh bay voi trung vi va tii phan vi (in- terquartiles). Wilcoxon signed-rank test dugc sir dung de kiem dinh su khac biet vl gia t4 trung binh cua nang lugng toan phdn va phdn tram nang lugng tir protein, glucid va chat beo giiranam 2004 voi nam 2009. He s6 tuong quan Spearman cung dugc tinh de kiem tra su tuong quan giira cac so do lugng chdt dinh

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TC. DD&TP 10 (2)-2014 duong trong khdu phdn an tgi thoi dilm

bat dau nghien cuu va sau 5 nam theo doi. Chiing toi dimg gia tri dilm cdt 0,2 de ket luan la co thay d6i theo thai gian hay khong [12]. Ngoai ra, trong nghien cuu nay, nang lugng hoac chdt dinh duong trong khau phdn an hdng ngay dugc xem la duy tri t6t theo thoi gian nlu cac doi tugng co miic nang lugng hay chat dinh duong trong khau phan an

"thap", "trung binh" hoac "cao" a nam 2004 vdn duy tri miic xip hang do a nam 2009. De chiing minh dilu nay, chiing toi da chia nang lugng va chdt dinh duong trong khau phan an thanh cac tam phan vj: thap nhat (L), trung binh (M) va cao nhat (H), va tinh chi s6 Kappa hieu chinh (k). Sir duy tri dugc dinh nghia la t6t nlu cac doi tugng van trong ciing cac tam phan vi, ca thoi diem nen lan sau 5 nam theo doi. Neu cac doi tugng chuyen sang tam phan vi lien ke, sir duy tri dugc xem nhu o miirc trung binh. Va nlu ho di chuyen ngau nhien vao bat ky cac tam phan vi khac trong nhirng nam sau, su duy tri dugc xep loai kem. Kruskal-Wal- lis test dugc sir dung de khao sat su khac biet cua nang lugng toan phan, cac chat dinh duong va phan tram nang lugng tir cac chat dinh duong giGa cac tu phan vi ciia BMI. Trong nghien cuu nay, chiing toi con khao sat moi lien quan cua nang lugng toan phan va phan tram nang lugng tir protein, glucid va chat beo voi BMI. Mo hinh tuyen tinh da bac dugc stir dung dl kilm soat cho anh huong cua viec chgn mau cum (voi don vi cum la truong) va su tuong quan trong chinh ban than moi doi tugng khi do lap di lap lai trong nghien cuu theo doi dgc bang mo hinh GLLAMM trong STATA 12.

Chiing toi chay mo hinh rieng biet cho tung gioi tinh. BMI dugc su dung thay cho BMI z-score nhu mgt so tac gia de nghi doi voi nghien cuu theo doi doc [13].

III. KET QUA VA BAN LV^N:

Vao liic bat dau nghien ciiu, 759 trong s6 784 hgc sinhTHCS (dugc chgn tu nghien ciru cat ngang) dong y tham gia nghien cuu. Trong so nay, co 7 d6i tugng dugc loai ra khoi phan tich do co trung binh nang lugng an vao <500kcal/ngay bay >5000kcal/ngay, vi vay chi con 752 hgc sinh co du lieu ve an uong dugc phan tich. Den nam 2009 chi con 533 hgc sinh CO du dG lieu ve an uong va cac chdt dinh duong hap thu. Dac diem ciia d6i tugng nghien curu a tai thai diem bdt ddu nghien ciiu va sau 5 nam theo doi dugc mo ta trong Bang 1. Trung binh BMI, nang lugng toan phan va lugng protein, glucid, chat beo trong khau phan an khac nhau mgt each co y nghia giGa nam va nu. Tu nam 2004 din 2009, BMI tang dang kl 6 ca 2 gioi (tir 20,lkg/m- len 23,5kg/m^ d6i voi nam va 18,lkg/m^len 20,6kg/m^d6i vai nu). BMI cua nam cao ban cua nu (p

< 0,001). Moi nam BMI deu tang, nhung tang 6 nam nhieu hon 6 nu.

Bang 1 cung cho thay nam co trung binh nang lugng va cac chat dinh duong trong khau phan anhang ngay cao ban nu. Nhin chung qua 5 nam theo doi trung binh nang lugng va cac chat dinh duong deu tang mgt each co y nghTa theo tuoi (p < 0,001) a ca nam lan nu. Nang lugng cung cap tu glucid chiem ty le cao nhdt, roi den nang lugng cung cap tir chat beo - 6 ca nam lan nu.

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TC. DD&TP 10 (2)-2014

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TC. DD&TP 10 (2)-2014 He so tuong quan Spearman va chi so

Kappa the hien su tuong dong va tuong thich cua cac gia tri nang lugng va chat dinh duong - danh gia tren cac doi tugng trong vong 5 nam nghien cim - dugc th§

hien trong Bang 2. Nhin chung, he s6 tuong quan cho thay nang lugng va chat dinh duong trong khau phan an dao dgng tu muc kem den trung binh giGa nam 2004 va 2009 6 ca nam idn iiG, thdp nhdt la tuong quan cua nang lugng tu protein

va nang lugng tu CHO, cao nhat la tuong quan cua nang lugng toan phan, cua protein va chat beo trong khau phan an.

Tuong quan ciia glucid deu thap ban tuong quan cua protein va chat beo. Voi chi so Kappa, chat beo va protein cung cho gia tri Kappa cao nhat, tiep theo la phdn tram nang lugng tir glucid. Trong hdu hit truong hgp, gia tri Kappa hieu chinh cao a nam hon 6f nG, dac biet la voi bien so phan tram nang lugng tir glucid.

Bang 2: He sd tirffng quan Spearman vd chi so Kappa hieu chinh danh gid su tirffng ddng vd tirffng thich trong 5 nam cua ndng lirffng todn phdn vd ndng lirffng tit cdc chdt dinh dir&ng trong khau phan dn theo gidi

Nanglugng Protein Glucid Chat beo Nanglugng Nang lugng Nanglugng Nanglugng Protein Glucid Lipid Nanglugng Nang lugng Nanglugng

tir protein tu glucid tCr chat beo

tir protein tir glucid tir chat beo

Nam , He so titang

quan 0,27 0,30 0,20 0,38 0,12 0,15 0,30 Gid tri Kappa

0,19 0,23 0,16 0,29 0,07 0,20 0,22

KTC 95%

0,17; 0,37 0,20; 0,40 0,09; 0,30 0,27; 0,46 0,01; 0,22 0,05; 0,26 0,20; 0,29 KTC 95%

0,16; 0,25 0,17; 0,29 0,09; 0,19 0,22; 0,34 0,03; 0,08 0,17; 0,26 0,17; 0,24

Nu He so tirtmg

quan 0,37 0,38 0,30 0,37 0,12 0,10 0,18 Gia tri Kappa

0,26 0,28 0,20 0,27 0,06 0,16 0,05

KTC 95%

0,27; 0,45 0,29; 0,46 0,21; 0,39 0,30; 0,47 0,02; 0,21 0,00; 0,20 0,08; 0,27 KTC 95%

0,22; 0,27 0,23; 0,32 0,16; 0,25 0,21; 0,34 0,01; 0,10 0,09; 0,21 0,02; 0,06 Khi cac d5i tumg nghien ciiu dugc

phan chia theo tit phari vi cua BMI, test Kruskal-Wallis cho thSy tre co BMI cao han (tvr phan vi cao) co nang lugng trong khiu phjn an tuong d6i nhiiu han han nhom co BMI thap hon (tii phan vi thip). Tuy nhien, luOng protein, glucid, chdt beo cung nhu phan tram nang

lugng tu protein, glucid va chat beo tuong tu nhau. Tai thai diem bit dau nghien ciiu, khong co su khac biet vl nang lugng toan phin va cac chit dinh duong trong khau phan an cung nhu phan tram nang lugng tir protein, glucid va chat beo giira cac nhom tii phan vi cua BMI(Bang 3).

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TC. DD&TP 10 (2)-2014 Bang 3: Trung binh ndng lu-ong, chdt dinh dirffng trong khdu phdn dn vd ty le nang lirgng tir cdc chat dinh dir&ng theo tieph

Toan bp mdu BMI (TB ± SD)

N5ng lirpng (truna vi, [25%, 75])

Protein (trung vj. [25%, 75]) Glucid (trung vi, [25%, 75]) Lipid (trung vj, [25%. 75]) NL tir protein (tmng vi, [25%.

751)

NL tir glucid (tmng vi, [25%, 75J)

NL Lipip (trung vj, [25%, 75]) IVdml

BMI (trung binh ± Dp l?ch chuSn) Nang lU(mg (trung vi, [25%, 75J)

Protein (trung vi, [25%, 75]) Glucid (trung vj, [25%, 75]) Lipid (tning vj, [25%, 75]) NL tir protein (trung vi, [25%, 75])

NL tir glucid (trung vi, [25%, 75])

NL tir Lipid (trung vj, [25%, 75])

^ttm S

BMI (trung binh ± DQ l^cll chuan) Nang ]ui?ng (trung vj, [25%, 75])

Protein (trung vi, [25%, 75]) Glucid (o-ung vi, [25%, 75]) Lipid(trtmgvi, [25%,75]) NL tir protein (trung vi, [25%, 75])

NL tir glucid (trung vi, [25%.

75])

NL Lipid (tning vi, [25% 75])

Quartile 1 16,9±1,4 2409,7 [1933.7; 3095,9]

99,2 [75,3; 125,9]

290,2 [196,2; 399,6]

59.3 [39,8; 80,8|

0,16 [0.15; 0,17]

0,47 [0,39; 0,54]

0,21 [0,18; 0,25]

11-241 16,8 ±1,3

2369,1 [1711,4; 2931,9]

88,1 [61,9;116,41

249,7 [185,3; 352,2]

573 [40,1; 81,8]

0,15 [0,14; 0,17|

0,44 [0,38; 0,52]

0,22 [0,19; 0,28]

n-113 17,2 ±1,4

2560,7

•[2029,9; 3356,1]

100,7 [84,0; 148,9]

324,6 [225,1; 481,8]

66,4 [51,3; 106,2]

0,16 [0,15; 0,18]

0,49 [0.44; 0,58]

0.23 [0,22; 0,29]

an vj cda BMI

Quartile 2 19,9 i 0,7 2516,9 (1954,4; 3223,1]

99,7 [76,6; 132,2]

291,3 [211.7; 419,0]

59,6 [41,1:88,3]

0,16 [0,15; 0,18]

0,47 [0,40; 0,54[

0,22 (0.18; 0,25]

n - 1S3 19,8 ±0,7 2378,8 [1813,7; 2988,7]

88.9 [64,1; 124,2]

250,0 (188,0; 411,9]

57,5 [38,1,87,1]

0,15 [0,13; 0.16]

0,45 [0,38; 0,54]

0,23 [0,18; 0,26]

n '130 20.0 ±0,7

2598,8 [2044,8; 3223,1]

101,5 (80,5; 128,8]

324,7 [234,2; 461,4]

71,9 [51,3; 90,1]

0,16 [0,15; 0,17]

0,50 [0,44; 0,57]

0,24 [0,21:0,28]

Quartile 3 22,4 ±0,8

2546,5 [1972,7; 32273]

101,1 (76,8; 130,0]

306,3 (222,0; 437,5]

60,3 [43,2; 88,9]

0,17 [0,14:0,18]

0.48 [0,42; 0,58]

0,22 [0,19:0,26]

n = 17I 22,3 ± 0,9

2383,7 (1773,3: 3435,7]

89,8 [63,3; 139,2]

251,0 [185,0:459,3]

59,9 [38,8:97,4]

0,16 [0,14:0,17]

0,46 [0,38; 0,54]

0,24 [0,18:0,28]

n-147 22,5 ±0,8

2684,8 [2129,1:3433,7]

102,2 [84,7; 148,2]

326,2 [247,9:515,4]

72,8 [54,0; 109,2]

0,17 [0,15; 0,18]

0,51 [0,45: 0,58]

0.26 [0,22; 0.28]

Quartile 4 27,3 ±3,1

2590,1 [2134,0: 3325,5]

101,7 (78,7; 135,9]

310,4 [326.3:449,4)

60,7 [45,5:91,7]

0,17 [0,14:0,19]

0,49 [0,44; 0,571

0,23 [0,19,0,26]

11 = 157 27,6 ±3,0

2393,3 (1957,0; 2980,1]

90,3 [68,8:115,3]

252,0 [209,1:383,7]

60,1 [40,6: 79,2]

0,16 [0,13:0,17]

0,46 [0,40; 0,52]

0,25 [0,18:0,26]

n-U3 27,9 ±3,4

2791,8 [2292,3; 3562,8]

102,6 (86.2; 142,8]

327,0 (285,2; 400,7]

74,2 [54,1:99,41

0,17 [0,14; 0,18]

0,52 (0,47; 0,58]

0,30 10,21:0,31]

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TC. DD&TP 10 (2)-2014 Chung toi cung chay mo hinh tuyen

tinh da bSc voi BMI la bi^n s6 phu thuoc va cac bien s6 khac: phan tram nang luong tir dam, glucid va chat beo duoc dua vao mo hinh cimg mot liic nhu la cac bi6n s6 dgc lap. Kit qua cho thay khong CO bien so dinh duong nao co lien quan mot each co y nghTa voi BIVII ngoai tru thoi gian danh cho van dong the luc va thoi gian danh cho man anh nho (so lieu khong trinh bay trong bai bao nay).

BAN LU^N

Cac ket qua nghien cuu cho thay: o muc do chung toan nhom nghien cuu, nang lugng va chat dinh duong trong Idiau phan an thay doi mgt each dang ke sau 5 nSm. O muc do ca nhSn, nhin chung thi nang Iucmg va chat dinh duong trong khau phan an chi duy tri 6 muc do kem den trung binh the hien qua he so tuong quan tuong doi thap. Co the vi 5 nam la khoang thai gian du dai de tao ra s\r thay doi trong thoi quen an u6ng nen kha nang giu: nguyen lugng chit dinh duong trong khdu phdn an la r4t ihkp [14]. Hon nua, lugng dam va glucid thay doi nhieu trong khi luong chit beo thay d6i it co the la do tre chiu anh huong boi thoi quen an uong cua ban be. Do vi khi tre Ion len va di hgc thi se gkn gui voi ban be hon trong khi luc tre con nho va 6 nha - chu yeu an do an do cha me chuan bi ma cac loai thuc phim "ben ngoai" lai co lugng chat beo va phin trSm nang lugng tu chat beo cao hon - nhu mgt nghien cuu tren vi thanh nien Viet Nam da tung bao cao [15]. Tir do dua den viec duy tri lugng chit beo an vao va nang lugng tu chit beo cao hon cac chat dinh duong khac.

Trong nghien cuu nay chung toi khong thiy moi lien quan gii5a nang

lugng toan phanva phan tram nang lugng tir chat beo voi BMI. That ra, m6i lien quan nay khong phai la hang dinh.

Co nhieu nghien cuu da chung minh dugc rang cac chat dinh duong sinh nang lugng (protein, chat beo, glucid) dong vai tro quan trong trong tinh trangbeo phi o tre em [4, 16], nhung ciing CO nhiing nghien cuu khac lai khong tim thay su lien quan nay [7], hoac tham chi con chung minh ngugc lai [17]. Nhieu tac gia cho rang nguyen nhan khong tim thay moi lien quan co the la do lugng thuc pham an vao dugc khai it hon thuc te [18]. Trong nghien cuu nay chung toi da toai trir cac gia tri (nang lugng) bat hgp ly ra khoi phan tich, do do moi lien quan giua chat dinh duong sinh nang lugng va BMI khong dugc tim thay trong nghien cuu nay khong phai la ket qua true tiep cuaviec khai it ban thuc te ma la do nang lugng toan phan co anh huong den tinh trang thira can-beo phi nhieu hon la phan tram nang lugng tir cac chat dinh duong rieng le. Nghien cihi hien tai chi thay co moi lien quan giira thoi gian danh cho van dgng the luc va thai gian danh cho man anh nho voi BMI, con moi lien quan giita chat dinh duong vdi BMI thi khong thay. Dieu nay co the la do su thay d6i hanh vi, thoi quen trong an u6ng cua cac em bi thira can beo phi lam cho m6i lien quan nay khong virng ben. Hon nua, nghien cuu cua chung toi thuc hien tren hgc sinh THCS la nhiing d6i tugng de bi tac dgng boi cac thoi quen an u6ng va cac hinh thiic van dgng tinh (nhu chai game, xem TV, ngoi hang gio sir dungintemet)tir ban be va dl thay d6i.

Chinh vi vay moi lien quan giiia thoi quen an uong/lua chgn thuc an trong nghien cuu ciia chiing toi cang it on dinh hon dan den viec duy tri nang lugng va 83

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T C . D D & T P 1 0 f 2 ) - 2 0 1 4 chat dinh duong trong khau phan an sau

thai gian 5 nam chi 6 muc do kem den trung binh.

Nghien ciiu cua chiing toi co mgt so diim m^nh. Truac tien, day la thiet ke nghien ciiu theo doi dgc cho phep theo d5i dugc su thay doi ciia nang lugng toan phan va chat dinh duong trong khau phan an trong thoi gian 5 nam va moi lien quan voi BMI, co kiem soat cho yeu to nhu: su day thi va phat trien ciia CO the. Thii hai, nghien ciiu nay chi thuc hi§n tren hgc sinh lop 6-7 va vi vay chiing toi co dieu kien thuan Igi trong viec theo doi chat che cac em trong vong 3-4 nam, truoc khi cac em chuyen qua truong cap 3 (kho theo doi chat che ban). Thii ba, chiing toi sir dung nhieu phuong phdp khac nhau de danh gia nhu tinh h$ s6 tuong quan, phan tram thong nhat giiia s6 do nam 1 va so do nam 5, chi so Kappa... Vi vay sir thay doi (hay giu nguyen) cua nang lugng va c h i t dinh duong trong khau p h i n an trong 5 nam da dugc so sanh mgt each c i n than.

Tuy vSy, nghien cuu ciing co mgt s6 han che: So lieu thu thap dugc tuy thugc vao kha nang n h a lai va viec khai vk mgt s6 lugng thuc p h i m bi tac dgng boi xu huang xa hgi (vi du mgt s6 mon an bi cho la "co hai" thi cac em khai it lai). Vi vay, diSu nay co t h i gop p h i n vao viec lam su duy tri m6t so thanh p h i n dinh duang chi dat miic do kem den trung binh. Ngoai ra, co mgt so bien so tam ly xa hgi khong dugc thu thap trong nghien ciiu nay va nhiing bien s6 nay co t h i anh huang d i n su thay d6i vk an uong va BMI cua tre.

IV. KET LUAN

Day la mgt trong s6 it nhirng nghien ciru danh gia su duy tri lugng chitdinh duong qua mgt thai gian dai thuc hien

tai TPHCM. Dac biet thai gian theo doi trong nghien ciiu nay den 5 nam. Su thay d6i nang lugng, c h i t dinh duong trong k h i u p h i n an r i t dao dgng cho thay rang viec can cii vao tinh hinh dinh du&ng ca nhan trong nam dau thi kho co the tien doan dugc nang lugng va chat dinh duang trong khau phan an a nam cuoi. Vi vay can mgt s6 chinh sach theo doi chat che lugng chat dinh duang trong khau phan an cua tre de kip thoi phong ngira tinh trang thira can-beo phi ngay cang gia tang 6 tre vi thanh nien TPHCM ngay nay.

L&i cdm ffn

Chiing toi xin trSn trgng cam on su iing hg cua Ban Giam hieu trudng Dai hgc Y khoa Pham Nggc Thach va Ban Giam d6c Trung tam Dinh duong TPHCM trong v i | c trien khai d i tai. S6 lieu thu th^p trong nghien ciiu nay d u g c thuc hien voi su tai trg cua T6 Chiic Nestle - Thuy sT.

TAI LIEU THAIM K H A O 1. Hong TK, Dibley MJ, Sibbritt D, Binh

PN, Trang NH, Hanh TT. Overweight and obesity are rapidly emerging among adolescents in Ho Chi Minh City, Viet- nam, 2002-2004. Int J Pediatr Obes.2(4):194-2D1.2007.

2. Dietz WH, Gortmaker SL. Preventing obesity in children and adolescents.

Annu Rev Public HeaIth.22:337-53.

2001.

3. Swinburn B, Egger G, Raza F. Dissect- ing obesogenic environments: the devel- opment and application of a framework for identifying and prioritizing environ-

mental interventions for obesity. Prev Med.29(6Pt l):563-70. 1999.

4. Maillard G, Charles MA, Lafay L, Thibult N, Vray M, Borys JM, et al' Macronutrient energy intake and adi- posity in non obese prepubertal children 84

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TC. D D & T P 10 ( 2 ) - 2 0 1 4 aged 5-11 y (the Fleurbaix Laventie Ville

Same Study). Int J Obes Relat Metab Disord.24(12):1608-17, 2000. Epub 2000/12/29.

5. MagareyA, Daniels L,BoultonT.Preva- lence of overweight and obesity in Aus- tralian children and adolescents:

reassessment of 1985 and 1995 data against new standard international defi- nitions. Med J Aust. 174:561 - 4. 2001.

6. Trichopoulou A, Gnardellis C, Benetou V, Lagiou P, Bamia C, Trichopoulos D.

Lipid, protein and carbohydrate intake in relation to body mass index. Eur J Clin Nutr.S6(l):37-43. 2002. Epub 2002/02/13.

7. Elliot SA, Tmby H, Lee A, Harper C, Ab- bott RA, Davies PS. Associations of body mass index and waist circumference with:

energy intake and percentage energy fi-om macronutrients, in a cohort ofaustralian children. Nutrition Journal.10{l):58-64.

2011.

8. Trang NH, Hong TK, Dibley MJ. Cohort profile: Ho Chi Minh City Youth Cohort- changes in diet, physical activity, seden- tary behaviour and relationship with overweight/obesity in adolescents. BMJ Open.2(l):e000362. 2012. Epub 2012/02/18.

9. Hong TK, Dibley MJ, Sibbritt D. Validity and reliability of an FFQ for use with adolescents in Ho Chi Minh City, Viet- nam. Public Health Nutr.l3(3);368-75.

2010. Epub 2009/08/27.

lO.Patterson E, Wamberg J, Kearney J, Sjostrom M. The tracking of dietary in- takes of children and adolescents in Swe- den over six years: the European Youth Heart Study International Journal of Be- havioral Nutrition and Physical Activ- ity.6Cl):91.2009.

11 .Rockett HR, Breitenbach M, Frazier AL, Witschi J, Wolf AM, Field AE, et al. Val-

idation of a youth/adolescent food fre- quency questionnaire. Prev Med.26{6):808-16. 1997.

12.Li J, Wang Y. Tracking of Dietary Intake Patterns Is Associated with Baseline Characteristics of Urban Low-Income African-American Adolescents. The Jour- nal of Nutrition.l38(l):94-100. 2008.

B.Berkey CS, Colditz GA. Works Better Than Change in BMlz Score for Longitu- dinal Studies. Annals of Epidemiol- ogy.l7(l):44-50.2007.

l4.Robson PJ, Gallagher AM, Livingstone MB, Cran GW, Strain JJ, Savage JM, et al. Tracking of nutrient intakes m adoles- cence: the experiences of the Young Hearts Project, Northern Ireland. Br J Nutr.84(4):541-8. 2000. Epub 2000/12/05.

IS.Lachat C, Khanh LNB, Khan NC, Dung NQ, Van Anh ND, Roberfroid D, et al.

Eating out of home in Vietnamese adoles- cents: socioeconomic factors and dietary associations. The American Journal of Clinical Nutrition.90(6):1648-55. 2009.

16.McGloin AF, Livingstone MB, Greene LC, Webb SE, Gibson JM, Jcbb SA, et al.

Energy and fat intake in obese and lean children at varying risk of obesity. Int J Obes Relat Metab Disord.26(2):200-7.

2002. Epub 2002/02/19.

17.Hassapidou M, Fotiadou E, Maglara E, Papadopoulou SK. Energy intake, diet composition, energy expenditure, and body fatness of adolescents in northern Greece. Obesity (Silver Spring).14(5):855-62. 2006. Epub 2006/07/21.

I S.Huang TT, Howarth NC, Lin BH, Roberts SB, McCrory MA. Energy intake and meal portions: associations with BMI per- centile in U.S. children. Obes Res.l2(ll):1875-8S. 2004. Epub 2004/12/17.

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TC. DD&TP 10 (2)-2014 Summary

THE ASSOCIATIONS BETWEEN ENERGY INTAKE, PROPORTION OF EN- ERGY FROIVI MACRONUTRIENTS AND BMI: A COHORT STUDY OF JUN-

IOR HIGH SCHOOL STUDENTS IN HOCHIIMINH CITY

Objective: To explore the relationships between energy, proportion of energy from macronutrients and BMI in junior high school students of HCMC. Methods: A cohort study was conducted between 2004 and 2009. Data on BMI, time spent for physical activity, TV watching habit and dietary intake were collected annually among 759 junior high school students. The extent of tracking of energy and macronutrient was investigated using Spearman correlation coefficients and weighted kappa statistics. Generalized Linear Latent and Mixed Models were used to investigate the association between energy intake and proportion of energy from protein, carbohydrate and fat with BMI. Results: Tracking of energy and macronutrient nutrient intakes at individual level was lowest for the percentage of energy from carbohydrate and from protein and highest for fat intakes (correlation coefficients and Kappa values were 0.38 & 0.29 for boys, and 0.29 & 0.27 for guls, respectively). The linear multi-level models showed that none of variables were signifi- cantly associated with BMI. Conclusions: The varied tracking observed in this cohort suggests that individual dietary patterns exhibited at the first year are unlikely to be pre- dictive of energy and nutrient intake at the last y«ar.

Keywords: BMI, nutrients, energy, adolescents

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