On Tue, 6 Jun 2000, Amadeus Schmidt wrote:
> Protein and fat together with carbs,
> both seem to increase the insulin response in length.
Interestingly, protein and fat alone also cause a substantial
insulin response, even though their glycemic index is very low.
This is not surprising once it is realized that insulin has many
jobs other than lowering blood sugar.
> You forgot to include your summary.. could you post it?
I'll try to remember this time.
> >But the brain can adapt to less. Again, see Lyle McDonald's
> >comments at http://www.cyberpump.com/nutrimuscle/lyle007.html
>
> Ok, I've read it and also Lyle's posting on the LC list which you
> referenced to on your posting under the "40g..." heading.
> I see, that Lyle downestimates my 80g computation to about 40g
> (involving even higher maximum fat-fuel percentages in ketosis for the brain
> as Dr.Walsh did - 73% as opposed to 40-60% ).
Yes. Lyle is allowing for a period of adaptation, after which
the brain's ability to use ketones is greater.
> I see, that you already had the idea to include 150g carbs (abt. 500kcal)
> directly for the brain requirement. Lyle's arguments just tell that
> it will end your ketosis, and that not all will be available to the brain,
> because other tissues will also use the carbs preferentially.
That's correct.
> Ok, but only in the time when insulin is up, this means only after a meal.
> In glucagon times when blood sugar comes from the glycogen-reserves
> (or neo..) only the brain dishes on it.
I'm not sure. I think muscle glycogen is also gradually
replenished. People on zero-carb diets do eventually regain the
ability to do high-intensity exercise, but it takes time. This
is why bodybuilders tend to favor the cyclic approach, with
periodic carb loading so that they can workout more often.
> BTW ketosis doesn't mean (you may correct me soon)
> that only now fat is used.
> It is burnt as the main fuel *anyway* also without ketosis and in average
> humans. But (smellable or detectable) ketone bodies are produced
> if fat is burnt *together* with gluconeogenesis.
> (very technical at http://www.zonehome.com/met/metlipid.htm
> under header: "6. Ketone Body Production and Utilization" )
My understanding is that ketone bodies are produced when the fat
is incompletely burned, and this happens when there is no
available carbohydrate for the job. As you have pointed out,
this is happening most of the time, regardless of carb intake.
But normally the ketones are themselves promptly burned as fuel.
Ketosis is the phenomenon of unburned ketones getting dumped into
the urine, etc., where they can be measured. That means ketones
are being produced faster than they can be used. This only
happens when carb intake is very low, and under these conditions
gluconeogenesis is happening, because gluconeogenesis is part of
the body's response to ketosis.
> Fats are burnt all day long normally predominately because
> "Approximately 180 grams of glucose are oxidized per day,
> mostly by those tissues for which it is essential "
> And this is only 720 kcal. The rest must be from fats, then.
> So even prodominating carbs in the (average) diet are converted to fat
> before burning(!).
That's right.
> IMO this is because of insufficient thiamin (and related vitamins)
> available to burn them directely.
I'm not sure. It would be interesting to know if this has been
studied.
> I think this also matches very well what Lyle writes on
> *high* carb diets in you second reference:
> >Overemphasis on the wrong types of carbs: we live in a carbohydrate crazy
> >society. I read a lot of papers
> >that say things like "Chinese and other cultures eat high carbohydrate
> >diets all the time and don't gain fat,
> >therefore carbs are not the culprit." Yeah, but they don't have fat free
> >everything made out of sugar. Or more accurately, they don't eat it.
> >
> >There's a big difference in eating a diet of 60% carbs primarily from
> >veggies and eating a diet of refined, sugary garbage.
> Note: the latter lacks thiamin, riboflavin, niacin, ascorbate.
Yes. It makes sense that these vitamins would increase direct
carb utilization; I just don't know if that has been confirmed
experimentally.
> >Always read Wittgenstein with a candy bar nearby. Wovon man nicht
> >reden kann, davon muss man schweigen.
> :-)
> I like this Wittgenstein citation.
> Among other things, it tells
> that there *are* some things it is not possible to speak about.
But we speak about them all the time on this list.
> Makes a whole new feeling to read some german words, also from Thomas.
Sorry I can't help with that. I had one semester of German in
grad school, and it has mostly left me, like unused ketones. All
that's left are quotations, like the one from Wittgenstein, and
things like "Freude schoene goetterfunken, Tochter aus
Elysium..." Not very useful, I'm afraid.
> Thomas, I haven't any reference how much energy the brain uses when
> "heavily" active. The resting consume i read about was 25 watts.
> (25*60*60*24 = 2160000 WattSeconds = kjoule per day) (=516kcal).
> Probably Wittgenstein reading neads a lot more, seriously.
PET scans show increased energy utilization in parts of the brain
that are "busy", which shows that heavy thinking (Schwer denken?)
indeed burns more calories than daydreaming. But it doesn't burn
*that* much fuel, or there would be no fat philosophers.
Todd Moody
[log in to unmask]
Here's the Insulin Index piece:
"An Insulin Index of Foods: The Insulin Demand Generated by 1000-kJ
Portions of Common Foods"
American Journal of Clinical Nutrition 66: 1264-1276 1997
Susanne HA Holt, Janette C Brand Miller, and Peter Petocz
Abstract:
The aim of this study was to systematically compare postprandial
insulin responses to isoenergetic 1000 kJ (240-kcal) portions of several
common foods. Correlations with nutrient content were determined.
Thirty-eight foods separated into six food categories (fruit, bakery
products, snacks, carbohydrate-rich foods, protein-rich foods, and
breakfast cereals) were fed to groups of 11-13 healthy subjects.
Finger-prick blood samples were obtained every 15 min over 120 min. An
insulin score was calculated from the area under the insulin response
curve for each food with use of white bread as the reference food (score
= 100%). Significant differences in insulin score were found both within
and among the food categories and also among foods containing a similar
amount of carbohydrate. Overall, glucose and insulin scores were highly
correlated (r = 0.70, P < 0.001, n = 38). However, protein-rich foods and
bakery products (rich in fat and refined carbohydrate elicited insulin
responses that were disproportionately higher than their glycemic
responses. Total carbohydrate (r = 0.39, P < 0.05, n = 36) and sugar (r =
0.36, P < 0.05,n = 36) contents were positively related to the mean
insulin scores, whereas fat (r = -0.27, NS, n = 36) and protein (r =
-0.24, NS ,n = 38) contents were negatively related. Consideration of
insulin scores may be relevant to the dietary management and pathogenesis
of non-insulin-dependant diabetes mellitus and hyperlipidemia and may
help increase the accuracy of estimating preprandial insulin
requirements.
(From Table 4)
Food Glucose Score Insulin Score
% %
________________________________________________________
white bread 100 100
Breakfast Cereals
All-Bran 40 32
Porridge 60 40
Muesli 60 40
Special K 70 66
Honeysmacks 60 67
Sustain 66 71
Cornflakes 76 75
Carbohydrate-rich foods
White pasta 46 40
Brown pasta 68 40
Grain bread 60 56
Brown rice 104 62
French Fries 71 74
White rice 110 79
Whole-meal bread 97 96
White bread 100 100
Potatoes 141 121
Protein-rich foods
Eggs 42 31
Cheese 55 45
Beef 21 51
Lentils 62 58
Fish 28 59
Baked beans 114 120
Fruit
Apples 50 59
Oranges 39 60
Bananas 79 81
Grapes 74 82
Snacks and Confectionary
Peanuts 12 20
Popcorn 62 54
Potato chips 52 61
Ice Cream 70 89
Yogurt 62 115
Mars bar 79 122
Jellybeans 118 160
Bakery products
Doughnuts 63 74
Croissants 74 79
Cake 56 82
Crackers 118 87
Cookies 74 92
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