Newsgroup: it.salute.alimentazione
Titolo: [Alimentazione a Zona] novità?

Salve
leggo spesso quest ng
ed in passato si è parlato di Alimentazione a Zona (Brian Sears)
volevo chiedere se ci sono novità ;-)
semplificando (molto)
è un'alimentazione che prevede un aumento di proteiene e grassi
una diminuzione dei carboidrati (specialmente quelli con indice glicemico 
alto)
inoltre indica che ogni pasto deve contenere una certa percentuali delle tre 
grandi classi
sono uno sportivo
e vedo che in questo mondo molti si avvicinano a questo tipo di 
alimentazione
ci sono studi recenti sulle possibili complicazioni nel tempo?
chi è contrario (tra cui molti nutrizionalisti, medici e allenatori 
italiani) dicono che questa allimentazione appesantisce il lavoro del fegato
ed alla lunga non può che fare male
grazie 

 Alimentazione a Zona (Brian Sears)
Brian? Barry! :)
-- 
Enrico C
* cut the ending "cut-togli.invalid" string when replying by email *

 ed alla lunga non può che fare male
non so dirti di studi fatti.
Io e mio marito stiamo seguendo questo regime da più di 5 anni
ormai, e stiamo benone... però non vuol dire molto!
Ciao 

 ed alla lunga non può che fare male
Dove l'hai letto?
Ci sono degli studi sui rischi per il fegato ma non della Zona...
della Atkins, che è più bassa di carb e alta di grassi... Cmq si
tratta di studi su topi e conigli, non so se ce ne sono anche sugli
uomini...
===
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed
Pol Arch Med Wewn. 2005 Mar;113(3):213-22. 	
    [Effect of high-fat diet, rosiglitazone on lipid profile, insulin
resistance and liver steatosis development]
    [Article in Polish]
    Tacikowski T, Nowicka G, Bujko J, Walewska-Zielecka B,
Dzieniszewski J.
    Klinika Chorob Metabolicznych i Gastroenterologii Instytutu
Zywnosci i Zywienia.
    The effect of diet on the development of liver steatosis is a
rarely analyzed problem. No effective methods of treatment of
nonalcoholic steatohepatitis have been developed, either. The aim of
the study was to assess the effect of high-fat diet and rosiglitazone
administration on (1) lipid parameters in the serum, (2) insulin
resistance and (3) development of liver steatosis. MATERIALS AND
METHODS: The material comprised 60 adult male Wistar rats. The animals
were divided into 5 main groups. The first three groups (AT, AR and
AL) were fed with high-fat diets (63% energy from fats, 23% from
carbohydrates), the animals in the remaining two ones (KH and KL)
received low-fat diet (10% energy from fats, 57% from carbohydrates).
Rats from the AL and KL groups received rosiglitazone (10 micromol/ kg
b.w.) through a gastric tube. After 9 weeks, the experiment was
terminated in groups AT, AL, KL whereas in the AR group high-fat diet
was replaced with low-fat diet after 9 weeks and the experiment was
terminated after further 7 weeks. RESULTS: The highest rates of liver
steatosis were observed in groups receiving high-fat diet, both in the
group where rosiglitazone was administered (10/12; 83.3%) and in the
group fed with high-fat diet only (8/12; 66.6%). In group AR, as well
as in both KH and KL groups no cases of liver steatosis were observed.
Group AT demonstrated the highest mean levels of total cholesterol in
the serum in comparison with AL (p<0.01), AR (p<0.001), KH (p<0.00001)
and KL (p<0.00001). Simultaneously, significantly higher triglyceride
level was found in group AT as compared with AL (p<0.001) and KL
(p<0.01). In the AL. vs. AT group, besides lower glucose level, lower
concentrations of insulin (p<0.0001), peptide C (p<0.000001), as well
as lower insulin secretion index (p<0.0001) and insulin resistance
(HOMA) (p<0.001) were also observed. A comparison of groups AT and KH
revealed a significant increase of mean glucose level (p<0.0001) and
peptide C (p<0.05) in group KH in comparison with AT. CONCLUSIONS: 1.
High-fat diet promotes the development of unfavorable lipid profile
changes (hypercholesterolemia, hypertriglyceridemia), insulin
resistance, as well as the development of liver steatosis. 2.
Rosiglitazone exerts a favorable effect on both lipid profile and
regulation of insulin secretion, but it does not reduce the risk of
liver steatosis.
    PMID: 16128278 [PubMed - indexed for MEDLINE]
===
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=16340038&query_hl=11&itool=pubmed_docsum
: J Physiol Pharmacol. 2005 Dec;56 Suppl 6:45-58. 	
    Metabolic and antioxidative changes in liver steatosis induced by
high-fat, low-carbohydrate diet in rabbits.
    Birkner E, Kasperczyk S, Kasperczyk A, Zalejska-Fiolka J,
Zwirska-Korczala K, Stawiarska-Pieta B, Grucka-Mamczar E.
    Department of Biochemistry, Medical University of Silesia, Zabrze,
Poland. 
skasp...@slam.katowice.pl
.
    Significantly decreased amounts of carbohydrates and increase of
fat in diet (Atkins' diet, Jan Kwasniewski's diet) may interfere with
liver metabolism because main source of liver energy are
carbohydrates. Large amount of fatty acid in diet may induce
overproduction of reactive oxygen species in mitochondria because of
increased oxidation and may cause steatosis. The influence of
high-fat, low-carbohydrate diet (contained 14 g% protein, 25 g% fat, 8
g% carbohydrate) and compared to usual habitual diet (13 g% protein, 3
g% fat, 28 g% carbohydrate) as a control on liver function was
examined in adult male rabbits. Fodder and water was ad libitum. The
experiment lasted 24 weeks. At the beginning and every six weeks
rabbits were weighed and blood was taken. Plasma glucose and
cholesterol concentration, activity of glutamate dehydrogenase,
alanine and aspartate in plasma and liver did not change.
Concentrations of triacylglycerols (TG) in plasma were lower in the
study group. Activity of aldolase increased in plasma and in liver in
the study group while activity of sorbite dehydrogenase decreased in
plasma at the end of the experiment. Malondialdehyde (MDA)
concentration increased in aorta with no changes in liver and
erythrocytes. Activity of glutathione peroxidase increased in
erythrocytes and liver while total SOD increased only in the liver.
High-fat, low-carbohydrate diet despite the lack of growth of the body
mass, modifies significantly the homeostasis of carbohydrates and
antioxidants in liver and enhanced production of TG in this organ,
resulting in its steatosis.
    PMID: 16340038 [PubMed - in process]

 Ci sono degli studi sui rischi per il fegato ma non della Zona...
Vale naturalmente l'AFAIK, cioč per quanto ne so. Chi ne sa di piů ben
venga :)
