This evidence suggests that type 2 diabetes does not have to be a progressive

[Pegasus]

That randle cycle explained video left me with a poor understanding of the difficulty switching from fat to carbs and back .
It seems designed to do exactly that . The switch from fat to carbs seems to be a lack of energy for current requirments . So I imagine (because it wasn't well explained ) this is either a lack of fats or a requirment for energy at a greater rate than can be supplied by fat .
Was the mechanism of switch from carbs to fat explained at all ? If so was the causal factors mentioned ? One can assume a lack of carbs would be one reason I assume there are others ?
I get the momentum/inerta thing but there is something else going on they do a very poor job of explaining .

Seems to me there is usually an energy mix at play . Under conditions of exercise the proportion of blood glucose used increases as intensity increases .

If constant high blood sugar causes the difficulty switching then Ben B is esentially right and god knows far easier to understand .
The randle cycle people propose that the body is caught in some sort of gear grinding difficulty caused by excessive carbs .
Is their argument with Ben B that by dumbing it down to a level most people can understand he used wrong terms ? They seem to suggest he has misrepresented what is happening ? In any case might I suggest the number of people that could fully understand their vid would be a handfull per million .
In they end result both recommend fewer carbs .

 

[Johnny D]

One is exercise physiology, the other is substrate availability and preference. Yes, when the energy demand spikes — like during high-intensity exercise — the body has to rely more on glucose (which it can get from muscle glycogen stores), because fat oxidation can’t keep up with the speed of ATP production needed. But that’s not really what the Randle Cycle explains. The Randle Cycle is more about how the presence of fatty acids inhibits glucose oxidation, and vice versa. It’s a regulatory system — not a response to energy demand, but to fuel availability and metabolic state.

And switching from carbs to fat will occur when insulin drops and free fatty acids increase in the blood — low-carb nutrition, fasting etc. So the hormonal shift tells the body to start oxidizing fat. Lack of carbs is part of the picture, but it's not just a "running low on fuel" thing — it’s regulated by hormones and enzymes.

 

[madyogi]

Yep. I'm familiar with the Randle Cycle and I see what you're saying. However, even without the fat, a high-carb or sugar-heavy diet can still lead to insulin resistance (which is more of a construct than a diagnosis, TBH) and eventually T2D. It’s just that the way it happens might be a little different compared to when carbs and fats are both in play. The Randle Cycle is definitely a big deal when both glucose and fat are around, but if you're constantly eating sugar, that’s still going to keep insulin levels high, which over time can make your cells less responsive to it. It’s really the constant high blood sugar that causes the issue, not just having fat in the mix.

I think that last statement is somewhat questionable. I don't think I ever said just having fat in the mix is the problem. I've clearly advocated for fat and protein, with very little carbs. And you clearly stated that when "both glucose and fat are around," the Randle Cycle plays a big role. It's the presence of both energy sources that causes the high blood sugar, because it "confuses" the cell as to which energy source it should be utilizing, so blood glucose isn't taken up as effectively as it would be in the absence of fat. Do we know for a fact that if a person who essentially just consumed carbs, without fat in the mix, would eventually develop Type 2 Diabetes? If the answer is "No," then having fat in the mix is critical. I don't know the answer personally, but I do know most versions of the standard american diet that lead to T2D are rich in both carbs and fat.

 

[madyogi]

One is exercise physiology, the other is substrate availability and preference. Yes, when the energy demand spikes — like during high-intensity exercise — the body has to rely more on glucose (which it can get from muscle glycogen stores), because fat oxidation can’t keep up with the speed of ATP production needed. But that’s not really what the Randle Cycle explains. The Randle Cycle is more about how the presence of fatty acids inhibits glucose oxidation, and vice versa. It’s a regulatory system — not a response to energy demand, but to fuel availability and metabolic state.

And switching from carbs to fat will occur when insulin drops and free fatty acids increase in the blood — low-carb nutrition, fasting etc. So the hormonal shift tells the body to start oxidizing fat. Lack of carbs is part of the picture, but it's not just a "running low on fuel" thing — it’s regulated by hormones and enzymes.

This is solid, as I understand it.

 

[madyogi]

That randle cycle explained video left me with a poor understanding of the difficulty switching from fat to carbs and back .
It seems designed to do exactly that . The switch from fat to carbs seems to be a lack of energy for current requirments . So I imagine (because it wasn't well explained ) this is either a lack of fats or a requirment for energy at a greater rate than can be supplied by fat .
Was the mechanism of switch from carbs to fat explained at all ? If so was the causal factors mentioned ? One can assume a lack of carbs would be one reason I assume there are others ?
I get the momentum/inerta thing but there is something else going on they do a very poor job of explaining .

Seems to me there is usually an energy mix at play . Under conditions of exercise the proportion of blood glucose used increases as intensity increases .

If constant high blood sugar causes the difficulty switching then Ben B is esentially right and god knows far easier to understand .
The randle cycle people propose that the body is caught in some sort of gear grinding difficulty caused by excessive carbs .
Is their argument with Ben B that by dumbing it down to a level most people can understand he used wrong terms ? They seem to suggest he has misrepresented what is happening ? In any case might I suggest the number of people that could fully understand their vid would be a handfull per million .
In they end result both recommend fewer carbs .

You're right, that in the end they both recommend fewer carbs and that Bart Kay is highly technical in such a way that 90% of people will check out. He's sort of claimed the space of debunking vegans online from the perspective of biochemistry and exercise physiology, so his "lane" is not to put things into lay terms. You're also right that there's usually an energy mix at play. In fact, there's always an energy mix at play. You're never, ever using entirely one substrate or another for energy. It's always a sliding scale. But as Johnny D has properly pointed out, under high energy demand, anaerobic metabolism will require almost entirely glucose utilization, which is why it can really only be deployed in short bursts.

 

[Johnny D]

I think that last statement is somewhat questionable. I don't think I ever said just having fat in the mix is the problem.

Fat in combination with carbohydrates. Correct? What you said was, "It looks like this is more a result of a "mixed" diet containing high fat in combination with high carbohydrates. Further, insulin resistance appears to be driven by whether or not the Randle Cycle is primarily invested in oxidizing fat for energy at the mitochondrial level."

I've clearly advocated for fat and protein, with very little carbs.

No argument from me on that. You have.

And you clearly stated that when "both glucose and fat are around," the Randle Cycle plays a big role. It's the presence of both energy sources that causes the high blood sugar, because it "confuses" the cell as to which energy source it should be utilizing, so blood glucose isn't taken up as effectively as it would be in the absence of fat.

It's true that the glucose/fat combo is what triggers the Randle Cycle (Though, I wouldn't characterize it as confusing the cell, and would say that a flip is switched during fat oxidation that says, "All fueled now, no need to oxidize glucose"), thus leading to high BG.

Do we know for a fact that if a person who essentially just consumed carbs, without fat in the mix, would eventually develop Type 2 Diabetes? If the answer is "No," then having fat in the mix is critical. I don't know the answer personally, but I do know most versions of the standard american diet that lead to T2D are rich in both carbs and fat.

It's going to be one of those, It depends but very often yes, kind of answers. If someone is highly active, regularly under eating, and maybe eating unrefined, whole-food carbs they can get away with consuming only carbs (though now they're bringing glycation, absence of essential nutrients, and other things into the mix). But a standard diet of refined carbs will keep BG elevated and lead to insulin resistance and diabetes, even in the absence of fat. T2D is chronically elevated BG by definition and the Randle Cycle isn't the only way to elevate BG.

 

[Pegasus]

OK so first as stated ealier I can not see how even 10% of people would fully understand that vid . It would be less than 1 % .

Hmm exercise physiology well lets see a slow walk will increase energy use relative to at rest and even a fast walk will change relative energy use . So in active people we are talking significant periods of time ..

It seems clear to me that the body is meant to use both carbs and fats . The randle cycle is meant to facilitate that .

So assuming both fat and carbs are in the diet as they are for most people what is causing the difficulity besides inerta ? So both are available why is there any difficulty . Now you might say because insulin is chronically elevated but then one must ask why . So one comes back to the explanation Ben B had at the start and the randle cycle vid seems to be grandstanding and pedantary .

 

[Johnny D]

OK. But my years of research on the subject have led me to the conclusion that we are meant to run on protein and fat. I agree with those who say that carbs will suffice in a pinch when protein and fat isn't available, but shouldn't be a regular source of fuel for us. All of the essential nutrients can be derived from protein and fat, but there is no dietary requirement for carbohydrates and they're missing essential nutrients. They also elevate blood glucose - whether through Randle Cycle or by simply consuming too much - which contraindicated for arterial health.

 

[madyogi]

It's true that the glucose/fat combo is what triggers the Randle Cycle (Though, I wouldn't characterize it as confusing the cell, and would say that a flip is switched during fat oxidation that says, "All fueled now, no need to oxidize glucose"), thus leading to high BG.

We agree here, and my use of "confuse" was misguided, as is any characterization that these processes are somehow "broken" in the case of insulin resistance. In fact, the cell is acting exactly how it's designed to act. Your characterization maps with mine here.

It's going to be one of those, It depends but very often yes, kind of answers. If someone is highly active, regularly under eating, and maybe eating unrefined, whole-food carbs they can get away with consuming only carbs (though now they're bringing glycation, absence of essential nutrients, and other things into the mix). But a standard diet of refined carbs will keep BG elevated and lead to insulin resistance and diabetes, even in the absence of fat. T2D is chronically elevated BG by definition and the Randle Cycle isn't the only way to elevate BG.

I won't disagree here, necessarily, but can you explain in a bit more detail how the SAD, in the absence of fat (this is hard to really pin down, because I don't know anyone on the SAD that really has a diet low in fat, whether it's fried foods, meat products, butter, cheese, creamy sauces and salad dressings, etc), gets T2D? Would it just come down to an energy demand issue, consuming more calories from carbohydrate than is needed for daily activity and at a faster rate than the excess can be stored, making the Randle Cycle more or less irrelevant?

I just think you'd be hard pressed to find someone just casually consuming the SAD without having a moderate amount of fat thrown in there.

 

[madyogi]

OK so first as stated ealier I can not see how even 10% of people would fully understand that vid . It would be less than 1 % .... assuming both fat and carbs are in the diet as they are for most people what is causing the difficulity besides inerta ? So both are available why is there any difficulty . Now you might say because insulin is chronically elevated but then one must ask why . So one comes back to the explanation Ben B had at the start and the randle cycle vid seems to be grandstanding and pedantary .

I agree the Bart Kay (Randle Cycle Biochem Guy) is pedantic and dismissive. That's kind of his "schtick," and I agree his content is often highly technical. I'm a highly intellectual guy and find the pedantic stuff entertaining, so I can follow the vids (admittedly after a second viewing) and don't mind the pedantry in small doses. To each his own.

It seems clear to me that the body is meant to use both carbs and fats . The randle cycle is meant to facilitate that .

The term "meant to" is making a lot of assumptions here. I think it's safer to say it's clear the body is capable of using both carbs and fats, and the Randle Cycle is the mechanism by which a cell can focus in on the most available source of energy at any given time, and "ramp up" utilization of that source, creating a lag time when it becomes necessary to bias toward the other (ie, when the initial source becomes scarce). Cells biased toward burning fat because of its abundance will be effectively insulin resistant.

Something like that, anyway.

 

[madyogi]

OK. But my years of research on the subject have led me to the conclusion that we are meant to run on protein and fat. I agree with those who say that carbs will suffice in a pinch when protein and fat isn't available, but shouldn't be a regular source of fuel for us. All of the essential nutrients can be derived from protein and fat, but there is no dietary requirement for carbohydrates and they're missing essential nutrients. They also elevate blood glucose - whether through Randle Cycle or by simply consuming too much - which contraindicated for arterial health.

We are in complete agreement here. I just find the "meant to" terminology problematic. I think it's just more accurate to say we run more efficiently on protein and fat, or it's just healthier to derive most of your energy from protein and fat, generally speaking.

 

[not2big]

From what I have read, carbohydrates are necessary because they are the body's primary and most readily available source of energy, particularly for the brain and muscles, and they also provide essential fiber for digestive health. While the body can derive some energy from fat and protein in the absence of carbs, a diet lacking carbs can lead to side effects like fatigue and ketosis, and some carbohydrates are crucial for proper bodily functions, nerve tissue, and red blood cell function

 

[madyogi]

From what I have read, carbohydrates are necessary because they are the body's primary and most readily available source of energy, particularly for the brain and muscles, and they also provide essential fiber for digestive health. While the body can derive some energy from fat and protein in the absence of carbs, a diet lacking carbs can lead to side effects like fatigue and ketosis, and some carbohydrates are crucial for proper bodily functions, nerve tissue, and red blood cell function

It's just not the case that you "need" dietary carbohydrates to do all these things. Gluconeogensis can provide all the glucose needed. I usually eat <50g of carbs a day, so I'm not carnivore or no carb, but I'm essentially in ketosis 80-90% of the time. Fatigue can be a symptom of transitioning to a ketogenic style diet, but that usually goes away, and being in ketosis is often the goal for people on Very Low Carb Diets.

Here are a couple of videos explaining the details:

A technical discussion by an anatomy expert:

Pieces of the above video broken down by the doc who founded the Duke Keto Medicine Clinic:

Dr. Berg is pretty good at explaining this here:

All that said, depending on preferences, energy demand, and other individual factors, some dietary carbs may be more optimal. As we've mentioned previously, the body is capable of utilizing both fuel types. However, it's just not the case that the body needs dietary carbs to do its thing.

 

[Pegasus]

Yogi So re Bart Kay vid as we are agreed much is pedantary can you tell me if there is an actual point beneath all the technical stuff ? He goes along explaining the randle cycle as though he has some major point of difference with Ben B but it is not clear to me what it is . Both say excess carbs are an issue .

In short he is clear as mud on geting an actual point across . Great if you are into pedantary and technical talk for it's own sake but for the rest of us is there an actual take away point ?

 

[madyogi]

Yogi So re Bart Kay vid as we are agreed much is pedantary can you tell me if there is an actual point beneath all the technical stuff ? He goes along explaining the randle cycle as though he has some major point of difference with Ben B but it is not clear to me what it is . Both say excess carbs are an issue .

In short he is clear as mud on geting an actual point across . Great if you are into pedantary and technical talk for it's own sake but for the rest of us is there an actual take away point ?

Not much difference, really. To me, it seems like more of a semantic disagreement than a practical one. Ben B refers to Insulin as a dictator, Kay takes issue with that, because it's too simplistic. He wants more nuance. Ben B also repeatedly says the machinery in the cell gets broken or out of wack, while Kay points out this simply isn't the case. It's a heuristic, and heuristics apparently bother Kay (they kinda bother me too), but in a practical sense, they "work."

There's a deeper philosophical question about whether heuristics can be considered "true" because the "work" even if they are technically inaccurate, but I digress.

Kay wants to be technically accurate and point out that the mitochondria are doing exactly what they're designed to do. They aren't broken, or whatever. He also wants more nuance about Insulin Resistance, and to bring attention to the fact that it is the mixture of the two energy sources in the diet that is mostly dictating this condition, not that the cell has become "broken" or "tired of listening" to the signal the pancreas is sending via Insulin (which is often the way this is described).

Again, as you point out, it all leads us to the same conclusion, which is basically "cut carbs," right?

In the end, I find Kay's pedantry to be entertaining, because I'm kind of an intellectual snob myself. It's a personality flaw I've come to recognize and try only to indulge in privately ;-). However, I like the technical details because I genuinely like to understand how things work as thoroughly as possible. It's not everyone's bag. Sorry it annoys you so. Like I said, heuristics work. So, it's all good. Kay comes across like a crotchety, jaded old professor who all the students try to avoid, while Ben B comes across like an approachable guy with better communication skills. Kay has more of the technical details figured out, but as we've pointed out ad nauseam at this point that only goes so far. For most, they just want a good heuristic. So, cut carbs in general, especially if you're going to have a moderate amount of fat in your diet and a less-than-athletic energy demand.

 

[Johnny D]

I won't disagree here, necessarily, but can you explain in a bit more detail how the SAD, in the absence of fat (this is hard to really pin down, because I don't know anyone on the SAD that really has a diet low in fat, whether it's fried foods, meat products, butter, cheese, creamy sauces and salad dressings, etc), gets T2D? Would it just come down to an energy demand issue, consuming more calories from carbohydrate than is needed for daily activity and at a faster rate than the excess can be stored, making the Randle Cycle more or less irrelevant?

Yes. As you know, all digestible carbohydrates will always be broken down into sugars, eventually becoming glucose. If that's all one is consuming, and they're consuming a significant amount of them, they'll go through blood sugar spikes and the subsequent insulin spikes. Since our cells have a finite capacity for energy production, the hormonal signaling kicks in to store the remaining glucose as glycogen. Muscles and liver have a finite glycogen storage capacity so the liver converts excess glucose to triglycerides (that's why we see high triglycerides in poor metabolic health). The cells become less and less responsive to the insulin, the pancreas has to produce even more, etc... Eventually it can't produce enough. Blood sugar is elevated at all times which is exactly what T2D is.

I just think you'd be hard pressed to find someone just casually consuming the SAD without having a moderate amount of fat thrown in there.

No doubt. I know some vegans who eat VERY little fat. Virtually none, but probably not literally none.

From what I have read, carbohydrates are necessary because they are the body's primary and most readily available source of energy, particularly for the brain and muscles, and they also provide essential fiber for digestive health. While the body can derive some energy from fat and protein in the absence of carbs, a diet lacking carbs can lead to side effects like fatigue and ketosis, and some carbohydrates are crucial for proper bodily functions, nerve tissue, and red blood cell function

I echo what Madyogi already said. I'll also add that fiber, in addition to being very tough on the intestinal walls, is entirely non-essential. Some people rely on it as a binder so they don't have loose stools but that's not an issue in a proper nutritional regimen of animal protein and fat. It's indigestible and utterly useless, otherwise, and it causes constipation for most people.

All that said, depending on preferences, energy demand, and other individual factors, some dietary carbs may be more optimal. As we've mentioned previously, the body is capable of utilizing both fuel types. However, it's just not the case that the body needs dietary carbs to do its thing.

Ya. If you're gonna eat carbs, there are some that are less bad. Similar to choosing which alcohol to drink, in a way.

 

[Pegasus]

Umm don't like to be the pedant here but vegan is not SAD.

 

[Johnny D]

Umm don't like to be the pedant here but vegan is not SAD.

Of course not (though in my circles it's starting to appear to be ) but we were discussing T2D in a solely plant-based nutrition, as well, so I was just adding that to the discussion.

 

[madyogi]

So, I inadvertently became the subject of an experiment that might be of interest here.

I had minor surgery to repair a hernia on Wednesday morning (9/17/2025) and, ever the citizen scientist, I decided to record what data I could before and after the procedure. What I discovered was interesting.

I took Blood Glucose and Ketone readings multiple times over about 2.5 days, along with intermittent blood pressure readings. On the morning of the surgery, I woke up at 5:15am after a fitful sleep. Prior to the surgery I wasn’t too worried about the whole thing (in my mind), but my sympathetic nervous system obviously was. My blood pressure was 160/100 with a pulse rate of 110 after getting all checked in and ready for consultation. I normally have a higher than average pulse rate, but both readings were unusually high for me. They performed the surgery without complication, and as I woke up, both my pulse and blood pressure had returned to expected levels. My wife brought me home, and as I rested for the next two days I took the following readings.

9/17/2025
5:30AM - ketones 1.5, BG 101

My glucose was already ~10-20 points higher than normal, probably due to poor sleep and/or stress over the impending surgery.

I arrived home about 10:00am and decided to run an experiment, measuring my ketones and BG as I took a new ketone supplement called Ketone IQ. This was just to see if the exogenous ketones had the effect they claimed to have, which they did. The rest was a surprise.

I took my first pain pill and the Ketone IQ drink at 12:30 pm.

12:25PM - ketones 1.5, BG 121
12:45PM - ketones 2.3, BG 123
1:00PM - ketones 2.1, BG 111, finished first meal after surgery (eggs with avocado and turkey)
1:30PM - ketones 2.7, BG 123, BP 125/77
2:15PM - ketones 2.1, BG 119, BP 126/79
3:35PM - ketones 2.1, BG 139, BP 134/84
4:05PM - ketones 1.8, BG 131, BP 135/85
4:40PM - ketones 1.8, BG 132

At this point I was kind of alarmed by my elevated blood sugar levels. They were off the charts for me, especially considering I was essentially fasted, save for some scrambled eggs with a bit of turkey, cheese and avocado. My mother-in-law brought us an Italian dinner, so I indulged in a carb-heavy meal with my family about 6:20pm, Shrimp Scampi with some salad and one piece of bread.

6:50PM - ketones 1.4, BG 142
7:20PM - ketones 1.4, BG 161
7:50PM - ketones 1.3, BG 132
8:20PM - ketones 1.2, BG 147
9:20PM - ketones 1.6, BG 147, BP 123/78

I went to bed about 9:45 after doing some research on Cortisol spikes post surgery and the potential effects on blood sugar.

09/18/2025

7:30AM - ketones 0.4, BG 124, BP 123/78
9:20AM - ketones 0.6, BG 112
12:15PM - ketones 0.8, BG 109, BP 140/86
12:30PM - meal of one chicken breast
1:00PM - ketones 1.4, BG 110, BP 120/81
2:26PM - ketones 0.6, BG 112
3:45PM - ketones 0.7, BG 109
5:00PM - ketones 0.7, BG 103
6:00PM - ketones 0.6, BG 94

Moved around a bunch, helping with dinner prep and such.

6:35PM - ketones 0.6, BG 113, ate a meal of chicken breast and thigh meat, 4 eggs, cheese, black beans, salsa, fermented veg (finished at 6:50)
7:20PM - ketones 0.6, BG 98, BP 122/80
7:50PM - ketones 0.4, BG 98
8:25PM - ketones 0.4, BG 98
8:55PM - ketones 0.4, BG 99, BP 128/82

9/19/2025

7:20AM - ketones 0.3, BG 95
9:30AM - ketones 0.7, BG 110, BP 126/86, P 67
10:45AM - ketones 0.7, BG 89
12:15PM - ketones 0.6, BG 96

So, this might be overkill for this thread, but I found it super interesting. This surgery essentially turned me into a T2D for about 24 hours, and then made me pre-diabetic for another 24 hours after that. Though I couldn't directly measure my Cortisol levels, my hypothesis is that Cortisol levels spiked post-surgery, which effectively raised my BG set point, making me appear "Insulin Resistant" for a period of time. Of course, I wasn't fully resistant, as evidenced by the response to my carb-heavy meal Wednesday night. The post-prandial spike was roughly 20 points, which is what I am accustomed to after such a "cheat meal," and my levels recovered within 90 minutes to roughly where they were prior to the meal. The main difference being my starting point, which was 50-60 mg/dL higher than I'm used to.

Elevated Cortisol activates the Adrenal Glands, signals the liver to produce more glucose via gluconeogenesis, and generally reduces cellular uptake of glucose in the blood. All this is to say, chronically elevated Cortisol levels also contribute to T2D in a way that isn't discussed as much as diet. My two-day, n=1 experiment proves this, at least for my particular body.

 

[madyogi]

Umm don't like to be the pedant here but vegan is not SAD.

Agreed. My point was mostly regarding people eating a "mixed diet," particularly of the SAD type. I doubt they are becoming T2D without having moderate fat involved, so the combination of carbs with fat is critical to the whole Randle Cycle blocking scenario we have been discussing. Don't get me wrong, that's not an endorsement of eating a vegan diet, just an admission that 70% carbs/25% Protein/5% fat probably doesn't cause the Randle Cycle to inhibit carb utilization in any significant way. That said, I still find it hard to believe a vegan is only getting 5% of energy from fat. If they're eating olives, avocados, nuts, etc, they're getting a fair amount of fat.

Anyway, I did want to circle back to Bart Kay and pedantry. He clearly states in several of his videos that it's an act meant to provoke visceral reactions to "get clicks." He says if he just did dry science-based videos no one would watch (maybe I would ;-), but by playing this "mean" character, he gets more attention to his message, which is that dietary carbs are unnecessary and contraindicated for optimal health for most humans. I tend to agree with him, and I'm quite sure if you met him in person he wouldn't be as nasty.