I was wondering if anyone knew how much glycogen is derived from gluconeogenesis based on grams of fat and the breakdown of protein. Also, how much glycogen is required by the body each day? I am so busy right now so I was looking for this information as I would do some research but also some information from some people who might know as this would be valuable.
Also, does going Keto stress certain parts of the body and raise cortisol? I know it is beneficial as well. And, does converting protein to glycogen create negative effects on the body as this seems to be a unique process. Thank you for anyone who has any advice or who has tried to help.
I don't think there is an exact answer to your question about #grams of fat and protein in gluconeogenesis, but here are some thorough reviews you may enjoy
Some of the highlights are
little postprandial hepatic glycogen synthesis takes place if gluconeogenesis is inhibited
approx 40% of liver glycogen repletion could be from lactate
the availability of lactate or its uptake by the liver determines the rate of glycogen synthesis, within the range set by the glucose concentration
A maximum of 27% of glycogen repletion occurred via the direct pathway, with most of the remainder contributed by compounds such as lactate, alanine, and glycerol
alanine is the substrate of choice for the liver, glutamine is the choice for the kidney
under normal re- feeding conditions the bulk of liver glycogen is formed by an indirect pathway involving the sequence glucose- lactate- glucose-6-P - glycogen, whereas muscle glycogen is formed by the conventional, direct pathway: glucose - glucose-6-P - glycogen.
it also depends on the person, in obese patients: a) fractional gluconeogenesis is increased; b) overall endogenous glucose production is unchanged due to a proportional inhibition of glycogenolysis; c) liver glycogen concentration is increased.
Body needs about 100 grams of glucose per day when not keto adapted and it WILL get it.
Amount of carbohydrate required by brain ~100 Breakdown of 180 grams of TG 18 Breakdown of 75 grams of protein 75 Total carbohydrate produced per day 93 in the liver
Once keto-adapted the brain will use much less glycogen and instead use ketones.
Keto-Adapted brain needs less than 40 grams/day. 180 grams of fat = 18 grams of glucose 20 grams of protein = 20 grams of glucose
and there you have it.
Conversion of protein to glucose is as normal as any other bodily function and occurs when dietary protein is consumed or during glucose 'starvation' from muscle stores.
For the stress and cortisol question, please see this question and my answer to it: Why do people consider ketosis “stressful” to the body?
Barry Groves' site, Second Opinions, has an article, by Professor John Yudkin, which contains this paragraph:
Dietary proteins are converted to glucose at about fifty-eight percent efficiency, so approximately 100g of protein can produce 58g of glucose via gluconeogenesis.[v] During prolonged fasting, glycerol released from the breakdown of triglycerides in body fat may account for nearly twenty percent of gluconeogenesis.[vi] Body fats are stored as triglycerides, molecules that contain three fatty acids combined with glycerol. The fatty acids are used directly as a fuel, with the glycerol stripped off. This is not wasted. As the glycerol is nearly ten percent of triglyceride by weight and two molecules of glycerol combine to form one molecule of glucose, this also supplies a source of glucose.
Link to article, "Why Low Carb Diets Must Be High Fat"
There are some fascinating papers listed in the references. I'm enjoying going through them.
In terms of meeting glucose needs through gluconeogenesis from fat-derived glycerol, your standard long chain fatty acid triglyceride is ~10% by weight of glycerol.
I've not found radiolabel tracer studies that quantify the contributions of various substrates for gluconeogenesis. We do recycle lactate and such too, so the contribution from amino acids is less than most estimate, but even fully keto-adapted you do require soe protein to sustain this process.
So, 58% protein can be converted to glucose and only about 10% fat? If you're working out and emptying your glycogen stores daily on VLC diet, does this mean you should eat above maintenance calories from protein/fat? VLC metabolic advantage?