When you're in ketosis, what does your body do with the few carbs you do take in?

[ad_astra]

When you're in ketosis you are burning fat for fuel. What does your body do with the limited amount of carbs you do take in? (The incidental carbs, carbs you take in that don't knock you out of ketosis).

I'm just curious as this thought occurred to me today.

[saintsparrow]

If the carb can be converted to glucose it will be

[jgrecbets]

When you're in ketosis you are burning fat for fuel. What does your body do with the limited amount of carbs you do take in? (The incidental carbs, carbs you take in that don't knock you out of ketosis).

I'm just curious as this thought occurred to me today.

converted to glucose and used for fuel as well. Your body can't run on 100% fat and ketones, and still does need some glucose to operate. I believe your brain in particular uses something like 75% ketones and 25% glucose once it is fully adapted to ketosis if I recall correctly.

Even on ZERO carbs, your body still finds ways to create glucose (protein can be converted to glucose)

[MikeK46]

When you're in ketosis you are burning fat for fuel. What does your body do with the limited amount of carbs you do take in? (The incidental carbs, carbs you take in that don't knock you out of ketosis).

I'm just curious as this thought occurred to me today.

Your body maintains a very narrow range of blood sugar. When you're in ketosis due to low carb intake, your liver is constantly trying to keep up with maintaining blood sugar through conversion of glycerol (from breakdown of fat) to glucose. This is called gluconeogenesis. A few ingested carbs will simply supplement the glucose that is produced via this process, thereby very slightly decreasing the rate of gluconeogenesis for a short period of time, but not enough to stop it. Enough ketones will still be produced to keep you in ketosis. Or, if these incidental carbs are few and complex enough (with a very low glycemic index), they may not have any effect on gluconeogenesis/ketone production at all, since there will not be a high enough influx of glucose from the ingested carbs to trigger any insulin from the beta cells in the pancreas.

[ad_astra]

Thanks for the responses guys. You guys are so knowledgeable.

MikeK -- just a quick question. So even if you are eating a limited # of carbs (say under 30g) if they're not very low GI they still trigger an insulin response? Is this bad?

[MikeK46]

Thanks for the responses guys. You guys are so knowledgeable.

MikeK -- just a quick question. So even if you are eating a limited # of carbs (say under 30g) if they're not very low GI they still trigger an insulin response? Is this bad?

It's absolutely normal. The average sized meal, regardless of carb content, will trigger additional insulin response and raise blood insulin levels. While not to the degree of carbs, fat and especially protein are insulogenic as well, despite not raising blood sugar. Certain protein rich foods can produce as much of an insulin spike as carb rich foods!

For example, 300 calories of cream result in a 10 picomole per liter (pmol/L) increase in blood insulin concentration, while 300 calories of casein protein will almost triple the baseline insulin levels.

Check out the discussion in this thread:

http://board.crossfit.com/showthread.php?t=43093





http://high-fat-nutrition.blogspot.c...-dr-davis.html

Here's one study on insulin response after ingestion of fat:

http://www.ajcn.org/cgi/content/full/88/3/638

Insulin response after ingestion of protein:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC292828/

http://jn.nutrition.org/cgi/content/full/135/6/1547S

http://ebm.rsmjournals.com/cgi/content/full/224/3/159

Insulin secretion after digestion of common foods:

http://www.ajcn.org/cgi/reprint/66/5/1264