GNG is Context Driven

I encouraged someone in a Facebook group to increase his protein intake. Let’s call him Josh (not his real name). Josh is a Type 2 Diabetic who controls his diabetes with the low carb diet (not intermittent fasting).

Josh was afraid to increase his protein because in the past when he upped his protein his blood sugar went up the next morning.  This discouraged Josh in the past from eating a higher protein amount thinking it was making his blood sugar higher. But Josh bit the bullet and decided to try and drop his fat intake and increase his protein.

True to his past experiences, this time his blood sugar went up again but he stuck with it and saw his blood sugar fall. It took some days but it did improve. His blood sugar numbers (in the morning) on the new higher protein were 126, 147, 152, 186, 155, 160, 155, 134, 128. Those first four days would have scared me but to his credit he stuck it out.

Why the Increase in Blood Sugar?

Cahill explained this effect in his study on starvation. Here’s the chart from that study.

I’ve looked at this before in this BLOG but let’s look at it in this particular instance to try and understand why Josh’s blood sugar went up.
Josh’s numbers look a lot like the GNG values in Cahills’ curve above – they are just delayed a bit. It took at least a day or two for Josh’s glycogen to drop since he is eating three meals a day (unlike Cahill’s paper where the subjects were starved). 

Type 2 Diabetics are also really good at GNG. We produce 2x-3x the glucose from GNG than non-diabetics. That is part of why we get exaggerated responses in our blood sugars.  I think it has to due with insulin resistance in the liver. The Type 2 diabetic’s liver is Insulin Resistant meaning it doesn’t listen to the clue that rising insulin is giving that it needs to drop the production of glucose (ie, GNG). 

GNG is done in the liver until glycogen and TG stores are gone. That only happens with a sustained caloric deficit or alternately a longer fast. Cahill points out that GNG is done later in the kidneys, etc which are apparently signaled more by the presence of increased ketones. Josh reported seeing his ketone production increasing. This is as a response to a caloric deficit and the drop in glycogen and TG stores.  Ketones have to go up when glucose drops because our brains need energy.

Context, Context, Context

We diabetics get concerned about our blood sugar but we sometimes don’t understand the context (reason) that the blood sugar goes up. My goal is to better understand for myself and help explain the context to others.

What Josh has now learned is that the increase in blood sugar follows a pattern where it happens for several days then stops to drop. If he keeps this up long enough he will see it level out at a good number. The event (blood sugar going up) needs be put into the proper context (trends, what the protein is doing in the body, etc).

Increases in blood sugar can be a sign (and are in this context) of the start of a caloric deficit which leads to weight loss. The body has to do GNG to make up for the lost energy from food.

This is where the people who say GNG is demand driven are right and wrong. GNG is context driven as Cahill demonstrated clearly. The demand for GNG changes in the context of glycogen status. 

The first evidence that you are doing the right thing with blood sugar shows exactly the opposite and leads you to think you are doing the wrong thing. If you try something for three or four days and it gets worse every day it confirms your fears that it’s not good. But if it starts to turn a corner it encourages you to press on.

Cortisol is [Partly] to Blame

A part of the reason is that the first few days of a caloric deficit (or fast for that matter) increase cortisol. Your body is telling you to get up and find/eat more food. Your body could care less about whether you’ve got enough energy stores (body fat). It just knows that you need to get up and hunt down or gather in dinner. 

Cortisol and Dawn Phenomenon

Increasing cortisol is what coincidentally happens before you get up in the morning. Your body is giving you the cortisol boost to get you moving. And for a diabetic, even though their last meal was 12 hours before, their blood sugar spikes up. The blood sugar wasn’t spiking up from any particular food. It was spiking up because of the cortisol that was being produced.

Josh’s blood sugar went up because he was not getting enough calories and his body was pumping out cortisol. That’s a completely good thing in this case since it signals good things are happening. It sucks that the blood sugar goes up, but it’s completely expected for several days as Cahill shows. Stay at the caloric deficit and it will begin to drop.

GNG is Context Driven

Just because GNG is demand driven doesn’t explain the demand. The demand for GNG is produced when glycogen stores drop and ketone production hasn’t kicked in enough yet. That happens every morning in the Dawn Phenomenon.

Another way to put it is that the demand can change and it does (as Cahill put it) by the caloric deficit not being met by carbs we eat (Phase I), or glycogen stores (Phase II). Eventually the body will down-regulate the need for glucose and even GNG will drop(Phase II to Phase IV). Phase V is marked by a much higher level of ketone production which takes the place of energy from glucose.

Ketogenic Diet – Fat Adaptation

To my way of thinking, this is what is meant by fat adaptation and the ketogenic diet… Ketones being used primarily as fuel. Doesn’t come from eating a lot of dietary fat. Quite the opposite. If you eat a lot of dietary fat it will get converted to glycogen.

If you are in a caloric deficit and your glycogen stores are lowered it has implications on athletic performance. And this may be the necessary state for diabetics who are keto to be in the majority of the time in order to control their diabetes. It may be the case that we can’t control our diabetes effectively without losing performance in glycogen demanding sports (sports at higher intensities).

Easier Paths?

It would have helped if Josh had gone into this by way of Intermittent Fasting or even a two or three day fast since it would have smoothed the transition. 

The same chart can be used to help people understand why Low Carb PLUS Intermittent Fasting is an effective strategy for Diabetics.
Low Carb eliminates phase I since you are not eating carbohydrates.
Just doing Low Carb without Intermittent Fasting causes you to refill your glycogen stores every day.

An 8-12 hour cycle isn’t enough to deplete glycogen. The person stays in Phase II forever. Note that at 6-8 hours glycogen peaks and at 12 hours it’s starting to drop a bit. Glycogen has dropped quite a bit more between hours 8 and 20. 

Suppose you do a 20:4 intermittent fast (into Phase III). If you do that your glycogen stores are getting more depleted every day. It doesn’t take too many days for your glycogen stores to drop enough that you don’t refill them the next day – especially if you are Low Carb where it’s harder to refill the Glycogen stores.

That is why Intermittent Fasting works so well. But it has to be done long enough to start to downregulate GNG and upregulate ketone production. Starting at OMAD or a 20:4 margin worked for me. It’s what got me to my HbA1C of 5.2 (non-diabetic blood sugar control).

People mistakenly think that the magic of Intermittent Fasting is that you just happen to eat less calories. Maybe that’s true or maybe it isn’t but the real magic is that it depletes your glycogen stores. At some point your body has to be producing ketones. By depleting glycogen (exercise helps and hurts this BTW) you are on your way to ketone production.

Author: Doug

I'm an Engineer who is also a science geek. I was pre-diabetic in 1996 and became a diabetic in 2003. I decided to figure out how to hack my diabetes and in 2016 found the ketogetic diet which reversed my diabetes.

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