Bai 4
NHU CAU DINH DUONG CHO NGUOl BENH
MUC Tieu
1. Trinh bay diidc nhu cau dinh diidng cua con ngiidi va vai trb tac dung cua cac
chat sii dung lam thiic an.
2. Ke diidc cac loai thiic pham dang sii dung 6 Viet Nam.
3. Neu diidc nhiing dieu chu y khi sit dung thiic pham.
Cd the song du d trang thai nghi ngdi cung phai tieu hao mot so n&ng
ltfdng nh&m cung cap cho hoat dong cua cac cd quan. Khi hoat dong n&ng
ltfdng tieu thu tang len gap boi. De dap ting nhu cau ve n&ng ltfdng, cd the
phai sti dung vat chat cua chinh ban than minh va phai dtfdc bu d&p thtfdng
xuyen. Thtic an chinh la nguon vat chat chu yeu de bo xung vao phan nang 1-
tidng tieu had.
Dap ting nhu cau dinh dtfdng cua con ngtfdi chinh la l&p dtidc khau ph£n
an cua mot ngtidi dtfa tren stf hieu biet ve vai tro tac dung, nhu c&u cac ch£t
sii dung lam thtic sin.
1. NHU CAU DINH DlTClNG VA VAI TRO TAC DUNG CUA CAC CHAT
SIT DUNG LAM THIJfC AN
1.1. Nhu cau dinh dtfdng cua con ngtfdi
1.1.1. Nhu cau ve nang luting (calo)
- Nhu cau ve n&ng ltidng la de dap ting nhu c iu cua chuyen hoa cd ban
(duy tri sti song). Ngoai ra nhu cau ve n&ng ltidng con de dap ting hoat
dong cua cd the.
- Nhu cau nang ltidng tuy thuoc dac diem phat trien tting thdi ky cua con ngtfdi,
vi du: tre sd sinh: 110 calc/kg, tre 16n: 2100 - 2500 calo/ng&y, ngtfdi
trtfclng thanh: nam 3.600 calo/ngay, nil: 2.400 calo/ng&y.
- Phu nti c6 thai va ngtfdi lao dong n&ng nhu ciu n&ng ltfdng cao hdn ngtfdi
binh thtfdng.
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- Phan bo nhu cau nang ltfdng: Protein cung cap 15 - 20% nhu cau nang
ltfdng, lipid cung cap 30%, Gluxit cung cap 50 - 60% nhu cau nang ltfdng
hang ngay.
1.1.2. Nhu cau ve thiic an
- Trong qua trinh song, cd the luon luon trao doi chat vdi moi trtfdng ben ngoai,
dUa thiic an vao cd the va dao thai cac chat can ba ra ngoai moi trtfdng.
- Muon dap ling nhu cau nang ltfdng, cd the con ngtfdi phai lay nguon thiic
an lam nguon chinh: thiic an dtfdc chia lam 3 loai:
+ Thiic an huiu cd: bao gom thiic an co ban chat protid, glucid, lipid.
+ Thiic an vo cd: ntfdc va muol khoang.
+ Thiic an co nhieu vitamin: A, B (Br B2 -B6 ...), C, D, E.
1.2. Vai tro tac dung cua cac chat sii dung lam thiic an
1.2.1. Thiic an hitu ca
• Thiic an co ban chat protid.
- Nguon goc: co nhieu trong thit, ca, triing, tom, cua, oc, dau...
- Cau tao:
+ Protid la hdp chat hQu cd dtfdc cau tao bdi bon nguyen to hoa hoc: C, H, 0,N.
+ Acid amin la ddn vi cau tao va la nguon san pham thuy phan.
+ Co khoang 20 acid amin trong do co 12 loai co the ttf tong hdp con 8
loai acid amin khong thay the" nhat thiet phai dtfdc bo sung tii thiic an.
- Vai tro cua protein doi v6i cd the.
Dung nhii Angels da viet “Sii song la phtfdng thiic ton tai cua cac the
Protid”. That vay protein rat quan trong doi v6i cd the song, no la cd sd cua tat
ca cac qua trinh song xay ra d cd the d6ng vat va thiic vat.
- La thanh phan cua nhan va nguyen sinh chat cua moi te bao.
- Tham gia dieu khien hoat dong sinh ly cua cd the (cac hormon).
- Xuc tac cac qua trinh chuyen hoa (men).
- Bao ve cd the (khang the).
- Qua trinh ho h&p: tham gia tao nen Hemoglobin.
- Chuyen hoa: sau khi vao cd the thiic an co cau tao protid, dtfdi tac dung
lien tiep cua nhieu men tieu hoa khac nhau (pepsin, chymotripsin,
tripsin, minopeptidase) dtfdc thuy phan thanh acid amin ho&c thanh
peptid ng&n, dtfqfc hap thu qua niem mac ruot (nhd hien ttfdng khuyech
tan v& photphoryl ho&) v^o mau qua gan vdi he thong men khii amin,
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khtf carboxyl, transaminase hon hop acid amin dupe dieu chinh cho phu
hdp vdi nhu cau cua cd the (bo sung vao stf doi mdi cua protein bo phan,
te bao hoac tong hdp thanh albumin va globulin cua huyet tUdng) neu
thtfa acid amin se bi khtf amin de dtfa vao than chuyen hoa chung. San
pham cuoi cung cua protid la NH3, H20 , C 0 2 NH? dtfdc ket hdp vdi acid
glutamic de tao thanh glutamin. Glutamin dtfdc van chuyen bdi mau tdi
gan va than, d do no dtfdc thuy phan thanh acid glutamic va NH3 (nhd
men glutaminase) NH3 dtfdc giai phong bien thanh ure hoac dao thai qua
ntfdc tieu dtfdi dang muoi amoni.
- Binh thtfdng khi chuyen hoa 1 gam protid cho 4 calo.
- Nhu cau protid ngtfdi binh thtfdng trung binh ttf l-l,5g/kg/ngay, toi thieu
la 0,6 gam, dtfdi mtfc do se gay thieu protid.
- Trong do ty le protid dong vat/protid thtfc vat 50 - 60%.
Hinh 1. Cac there an giau dam
• Thiic an co ban chat lipid.
- Nguon goc: co nhieu d md dong vat, dau ca, dau lac, dau vtfng, dau o liu...
- Cau tao:
+ Lipid la este cua acid beo va cua alcol ho&c la din suat cua acid beo.
+ Co 2 loai lipid:
- Lipid thuan (este cua alcol va acid beo).
- Lipid tap (ngoai thanh phan tren can them nhom NH2 phosphat sulfat,...)
- Vai tro:
+ Cung cap nang ltfdng cao.
+ Chtfa nhieu loai vitamin tan trong dau va nhieu loai acid beo bao hoa
rat can thiet cho cd the.
+ Lipid la nguon dtf trtf nang ltfdng cho cd the.
- Chuyen hoa: thtfc in lipid sau khi dtfdc tieu hoa chu y£u d ruot nhd men
lipase cua tuy cho san pham thuy phan cua nhu ttfdng md gom acid beo
va glycerol. Nhtfng hat nhu ttfdng rat nho dtfdc h£p thu qua m&ng ruot
(nhd phan tfng phosphoryl hoa va vai tro cua tuy£n thtfdng thAn noi tiet
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lam tang hap thu). Sau do lipid dtfdc tong hdp lai d te bao mang ruot roi
vao he tu&n hoan. Dtfdc van chuyen dtfdi dang lipoprotein tdi cac to chtfc
md de dtf trtf (dtfdi dang triglycend) hoac tdi gan.
- San pham chuyen hoa cuoi cung la H20 ; C 0 2 va cung cap nang ltfdng.
- Binh thtfdng khi chuyen hoa hoan toan 1 gam lypid cho 9 kcalo.
- Nhu cau binh thtfdng cua con ngtfdi la 0,7 - 2g/kg/ngay.
• T h iic an co ban chat glucid
- Nguon goc: co nhieu trong gad, ngo, khoai, san, lua mi...
- Cau tao: la hdp chat htfu cd chtfa cac nguyen to" C, H, O ma trong phan tii
chtfa mot hay nhieu monosaccharid.
- Vai tro:
+ Cung cap nang ltfdng (chiem 2/3 tong nang ltfdng).
+ Tao hinh.
+ La thanh phan cau tao mot so" chat quan trong nhtf acidnucleic, gluco
protein, glucolipid...
- Chuyen hoa: thtfc an sau khi vao cd the nhd cac men tieu hoa (maltose, HC1,
dich tuy, dich ruot) trd thanh cac monosaccarit (glucose fructose, galactose)
dtfdc hap thu vao mau nhd qua trinh phosphoryl hoa d niem mac ruot) theo
tinh mach vao gan va bi gitf lai phan 16n d day de tao ra glycogen dtf trtf cho
cd the, mot phan co the cung cap nguyen lieu de tong hdp thanh cac chat
khac (protid, lipid) hoac dot chay de cung cap nang ltfdng.
+ San pham chuyen hda cuoi cung la H20 , C 0 2 va nang ltfpng. Binh
thtfdng khi chuyen hoa hoan toan 1 gam glucid cho 4 calo.
- Nhu cau binh thtfdng cua con ngtfdi la 5 -7g/kg/ngay.
1.2.2. Thiic an vo cct
• Ntfdc:
- Vai tro cua ntfdc trong cd the:
+ Tham gia vao cau tao cua cd the ntfdc chiem 70% trong ltfdng cd the
nhtfng phan bo" khong deu.
Vi du: ntfdc:
. Khu vtfc te" bao chiem 50%
. Khu vtfc gian bao chiem 15%
. Khu vtfc long mach 5%
. Ho&c trong gan, nao, da chiem 70%
. Tim chiem ’ ' 7 6- 80%
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. Than, phoi, mo lien ket 80 - 84%
. Mau 83%
. Cac dich sinh vat khac (ntfdc tieu, mo hoi, ntfdc bot) 95 - 99%.
+ Tham gia vao cac phan ting ly hoa cua cd the: phan tfng thuy phan,
phan ling hydrat hoa.
+ La dung moi hoa tan cac chat vo cd va htfu cd.
•* °
+ Van chuyen cac chat dinh diidng va cac chat can ba (san pham chuyen
hoa).
+ Gitf vai tro dieu hoa than nhiet.
+ Tham gia bao ve cac mo va cd quan (dich khdp, dich nao tuy).
- Nhu cau ve ntfdc cua cd the:
+ Phu thuoc vao can bang xuat nhap ntfdc, nhu cau ve ntfdc cd the dtfdc
dam bao bang hai cach: mot phan ldn do thtfc an, mot phan do qua
trinh chuyen hoa cac chat.
+ Nhu cau trung binh mot ngtfdi can 1,5 - 2 lit/ngay.
(Chu y: neu nhiet do moi trtfdng qua nong hoac lao dong qua nang nhoc
thi nhu cau ve ntfdc co the tang hdn).
• Cac chat muoi khoang
- Tac dung:
+ Gitf vai tro quan trong trong stf hoat dong va phat trien binh thtfdng
cua cd the.
+ Muoi chiem 4 - 5% the trong, tham gia vao thanh phan cua tat ca cac
te bao va mo cd the.
+ Muoi khong tan chiem ltfdng nhieu nhat, tham gia ca'u tao xtfdng.
+ Muoi hoa tan trong cac dich thtfdng phan ly thanh ion tac dung gay
nen ap suat tham tha'u (NaCI).
+ Tham gia vao he thong dem (H2C03/NaHC0) - t .l
+ Co tac dung dac biet vdi trang thai ly hda cua protein trong cac te bao
va mo.
+ Cd tac dung tfc che va hoat hda cac men.
- Nhu cau ve muoi:
+ Natri (Na+) la cation chinh cua dich ngoai bao, no cd vai trd trong viec
phan bo" dich ngoai bao va noi bao.
■ Nhu cau binh thtfdng (ngtfdi ldn) 6g («110 mEq).
• Neu an uong binh thtfdng nhu cau nay se dtfdc thoa man.
• Nguon cung cap Na: muoi NaCI, ca bien, tom bi£n...
> Neu thtfa ion Na se lam tang ap ltfc tham thtfu dich ngoai b&o, lim te
bao mat ntfdc, ngtfdi benh cd cam giac khat ntfdc.
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