Gość: Doki
IP: *.246-200-80.adsl-fix.skynet.be
09.07.03, 17:04
Nasz dyzurny promotor zywienia optymalnego znowu sie
uaktywnil.
Tak sobie poczytalem i co znalazlem, to wklejam.
Pierwszy artykul: byc moze zywienie optymalne to powrot
do zrodel, do czasow gdy nasi przodkowie siedzieli w
jaskiniach:
Colagiuri S, Brand Miller J. The 'carnivore
connection'--evolutionary aspects of insulin
resistance. Eur J Clin Nutr. 2002 Mar;56 Suppl 1:S30-5.
ABSTRACT: Insulin resistance is common and is
determined by physiological (aging, physical fitness),
pathological (obesity) and genetic factors. The
metabolic compensatory response to insulin resistance
is hyperinsulinaemia, the primary purpose of which is
to maintain normal glucose tolerance. The 'carnivore
connection' postulates a critical role for the quantity
of dietary protein and carbohydrate and the change in
the glycaemic index of dietary carbohydrate in the
evolution of insulin resistance and hyperinsulinaemia.
Insulin resistance offered survival and reproductive
advantages during the Ice Ages which dominated human
evolution, during which a high-protein low-carbohydrate
diet was consumed. Following the end of the last Ice
Age and the advent of agriculture, dietary carbohydrate
increased. Although this resulted in a sharp increase
in the quantity of carbohydrate consumed, these
traditional carbohydrate foods had a low glycaemic
index and produced only modest increases in plasma
insulin. The industrial revolution changed the quality
of dietary carbohydrate. The milling of cereals made
starch more digestible and postprandial glycaemic and
insulin responses increased 2-3 fold compared with
coarsely ground flour or whole grains. This combination
of insulin resistance and hyperinsulinaemia is a common
feature of many modern day diseases. Over the last 50 y
the explosion of convenience and takeaway 'fast foods'
has exposed most populations to caloric intakes far in
excess of daily energy requirements and the resulting
obesity has been a major factor in increasing the
prevalence of insulin resistance.
Ciekawe, prawda? Ci, ktorym dieta optymalna sluzy to
byc moze po prostu ludzie, ktorzy maja trudnosci z
adaptacja do zmienionej po ustapieniu lodowcow diety...
Co jednak sadzic o tych dietach dzis? Pomoc moze ten
artykul:
Bravata DM, Sanders L, Huang J, Krumholz HM, Olkin I,
Gardner CD, Bravata DM. Efficacy and safety of
low-carbohydrate diets: a systematic review. JAMA. 2003
Apr 9;289(14):1837-50.
ABSTRACT: CONTEXT: Low-carbohydrate diets have been
popularized without detailed evidence of their efficacy
or safety. The literature has no clear consensus as to
what amount of carbohydrates per day constitutes a
low-carbohydrate diet. OBJECTIVE: To evaluate changes
in weight, serum lipids, fasting serum glucose, and
fasting serum insulin levels, and blood pressure among
adults using low-carbohydrate diets in the outpatient
setting. DATA SOURCES: We performed MEDLINE and
bibliographic searches for English-language studies
published between January 1, 1966, and February 15,
2003, with key words such as low carbohydrate,
ketogenic, and diet. STUDY SELECTION: We included
articles describing adult, outpatient recipients of
low-carbohydrate diets of 4 days or more in duration
and 500 kcal/d or more, and which reported both
carbohydrate content and total calories consumed.
Literature searches identified 2609 potentially
relevant articles of low-carbohydrate diets. We
included 107 articles describing 94 dietary
interventions reporting data for 3268 participants; 663
participants received diets of 60 g/d or less of
carbohydrates--of whom only 71 received 20 g/d or less
of carbohydrates. Study variables (eg, number of
participants, design of dietary evaluation),
participant variables (eg, age, sex, baseline weight,
fasting serum glucose level), diet variables (eg,
carbohydrate content, caloric content, duration) were
abstracted from each study. DATA EXTRACTION: Two
authors independently reviewed articles meeting
inclusion criteria and abstracted data onto pretested
abstraction forms. DATA SYNTHESIS: The included studies
were highly heterogeneous with respect to design,
carbohydrate content (range, 0-901 g/d), total caloric
content (range, 525-4629 kcal/d), diet duration (range,
4-365 days), and participant characteristics (eg,
baseline weight range, 57-217 kg). No study evaluated
diets of 60 g/d or less of carbohydrates in
participants with a mean age older than 53.1 years.
Only 5 studies (nonrandomized and no comparison groups)
evaluated these diets for more than 90 days. Among
obese patients, weight loss was associated with longer
diet duration (P =.002), restriction of calorie intake
(P =.03), but not with reduced carbohydrate content (P
=.90). Low-carbohydrate diets had no significant
adverse effect on serum lipid, fasting serum glucose,
and fasting serum insulin levels, or blood pressure.
CONCLUSIONS: There is insufficient evidence to make
recommendations for or against the use of
low-carbohydrate diets, particularly among participants
older than age 50 years, for use longer than 90 days,
or for diets of 20 g/d or less of carbohydrates. Among
the published studies, participant weight loss while
using low-carbohydrate diets was principally associated
with decreased caloric intake and increased diet
duration but not with reduced carbohydrate content.
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