Gluconeogenesis: I keep hearing that it's only demand driven, can that be right?

(mole person) #1

I’ve read hundreds of posts now on Keto forums where people tell others not to worry about overeating protein, even by up to four times the recommended amount, because gluconeogenesis is demand and not supply driven. I’m having a problem squaring this with the fact that I know the body can’t store much in the way of amino acids and can only use so much protein in a given time period. If gluconeogenesis is demand driven then what is happening to all that surplus protein?

(Bacon is a many-splendoured thing) #2

Yes, the process of gluconeogenesis is driven by demand, not supply.

The protein you eat is broken down into its constituent amino acids, which go into the labile pool for use in constructing new proteins, gluconeogenesis, and other purposes. The remainder stays in the labile pool until needed. Truly excessive quantities (above 3 grams per kilo of body weight, according to Richard) get broken down into ammonia and carbohydrate. If the ammonia is produced at too great a rate to be excreted, ammonia toxicity can be fatal.

(Ron) #3

I know you said you have researched a lot so you might have already seen this -

(mole person) #4

Thank you. I’d heard so often that excess protein turns to glucose I thought that this “demand driven” thing had to be wrong. This will change how fussy I am about my exact protein load.

(mole person) #5

No! I haven’t seen this. And I happen to have insomnia at the moment so an extra long and sciencey blog fits the bill perfectly. :grinning:

(Bacon is a many-splendoured thing) #6

The experts are divided. Ben Bikman advises more protein as we age, because our ability to absorb it declines, whereas Ron Rosedale advises less protein as we age, because too much protein stimulates the mTOR pathway, with deleterious effects. I’d like to sit them in a room and lock the door until they sort it out, lol!

(Karen) #7

I’ve upped my protein a bit. Seems I can over eat anything including fat. I’ve heard Fung advise moderation on fat bombs, especially for women. Haven’t tried them yet but I like me some buttah.

K

(Jennifer Kleiman) #8

GNG is demand driven. For an extreme example listen to Jimmy Moore’s account of eating 270g protein daily as an experiment for a week, haha. His blood sugar remained pretty stable or if anything dipped a little low, despite consuming 6 chicken breasts at a sitting.

(Diane) #9

The following link shows Dr. Ben Bikman giving a presentation regarding gluconeogenesis and how it is affected by whether you are a carb burner or not. I find it fascinating and it put my mind at ease (somewhat) regarding how my protein intake might affect insulin. The meat of the argument starts about 10 minutes in, but he’s a great presenter and the set up helps to understand the issue.

(Brian) #10

I don’t think I could do that if I tried. Wow.

Last night, my wife and I split a large chicken breast between us. That was not all we had for supper, also had a bit of leftover chuck roast an a few veggies, but six chicken breasts? That’s a lot more than I could eat at a sitting.

#11

Can you tell (write) me more about that “labile pool”?

I was thinking you need to digest protein 24/7 to have constant supply of protein to maximize muscle growth when lifting.

(I came for the weight loss and stayed for my sanity... ) #12

As far as I understood gluconeogenesis is demand driven, but the insulin response is not. (Was it half of that from carbs?! :thinking:)
But i would not go tooo crazy about it. make sure your protein is fatty enough and eat to satiation whenever possible…

(Ron) #13

The liver is a major storage organ of iron, in which excess iron is stored as ferritin and hemosiderin. In addition to these proteins, an additional fraction of free iron is present in the form of the labile iron pool (LIP) within cells. The LIP is biologically active in intracellular metabolism via oxidation–reduction reactions, cell proliferation, and cell signaling.

#14

I’m not afraid of protein like many are, on lifting days I consume plenty of it BUT I also have issues with the demand/supply answer allowing a protein free for all for many. Before people like Ben Bikman went a little insane with it we had our “anecdotal” aka REAL LIFE experiences of millions showing that when we ate excess protein we’d stall out, gain weight, feel like crap etc. I can eat 200g on lifting days no problem, if I do that on a rest day I’ll completely go to crap, as will many others with the same symptoms of a carb binge. You cant hop on the supply/demand band wagon without coming up with a reason for so many of us with spiked blood sugar and carb like responses to protein when we knowingly consume more that we need. We know we can’t store it like glycogen and we know the process for burning off what we can’t use. That’s always convienently ignored when this gets brought up.

I’ll agree all day long that when it comes to GNG making glucose for our brains that’s demand driven, buts that’s very different argument than what happens when our dietary protein is too high for our needs.

(Todd Allen) #15

By dexa I’m just under 50 kg lean mass.

At 60 g of protein daily after a few days my 12 hour fasted blood sugar is roughly 70 mg/dl. At 120 g protein daily my fasted blood sugar is around 80 mg/dl. Averaging 180 g protein for a few days my fasted blood sugar is about 90 mg/dl and after a couple weeks I start experiencing symptoms I had on a high carb diet when I was prediabetic such as elevated body temp, night sweats and restless sleep. The higher I raise my protein level the more I have to restrict carbohydrates to sustain a given level of ketosis. I haven’t tried going to 240 g protein, but I expect it would get worse.

I’m not interested in debating what the theory is or what the typical results are for others. What I care about is how my body reacts. Fortunately it is simple to test and see.

(mole person) #16

After reading more about this I don’t think you’d expect any spike in blood glucose even if protein consumption was causing an uptick in gluconeogenesis. Gluconeogenesis is both demand driven AND increases with added protein.

It’s the rationale that was wrong. It’s no happening because the body is turning excess protein to glucose, but rather that the insulin response to protein is causing glucose to get shunted from the blood into the cells and thus there IS a actual demand for more blood glucose to prevent hypoglycemia and that’s why there is an increase in glucagon when you eat protein. You actually have a NEED for gluconeogenesis.

(mole person) #17

I’d watched this before but it was great and worth a second viewing. Honestly, I may give it a third go to really cement the content in my brain.

#18

Was this an intended pun? Bravo! :smile:

(mole person) #19

I’m interested in this as well.

(Jennifer Kleiman) #20

That’s almost exactly right to my understanding, except that the protein consumption triggers glucagon response directly, rather than the glucagon being triggered by low blood glucose. That’s why I see a glucose spike from drinking a 50g whey protein shake, the whey isolate triggers a huge insulin AND glucagon response and it takes 30-45 mins to balance out. The dynamics of the insulin & glucagon responses vary by quantity - insulin increases fairly linearly along with amt consumed, but glucagon tapers off, so if you or I consumed a huge amount the insulin will dominate the glucagon. These responses vary individually to some extent too, and of course are seriously deranged in diabetics