Dr Boz Calculates levels of autophagy using blood sugar/blood ketones ratio

(Barbara) #1

I always wished there was a way to KNOW if I ever was in a state of autophagy and it seemed like there was no way to measure it. The general consensus among respected sources seemed to say it would be safe to guess that water/salt fasting for a number of hours would start autophagy which would peak in about 3 days but there wasn’t a way to check or to be sure. At least that was my take away.

Watching this Dr Boz Youtube today beginning at about 22.00, https://www.youtube.com/watch?v=KXoa6dDVEyc&t=1546s She fairly confidently gives a way to estimate if your level of intensity of fasting was intense enough to reach certain levels of autophagy: by taking blood sugar and blood ketone levels, taking the results and dividing blood sugar level by ketone levels to get a ratio. For weight loss, the ratio should be between 70 to 100. If the goal is for autoimmune, the ratio should be 50-70. For cancer patients in order to stress cancer cells, the ratio should be less than 20 and should ONLY be attempted with a Doctor present.

I am fat adapted and after 17.5 hours of water fasting, my BS was 91 and my BK was 1.4 giving me a ratio of 65 which may have put me in the range of doing my autoimmune disease (exhibited in arthritis) some good. I’d feel more confident if the source was someone like Valter Longo at USC Davis, Ana Maria Cuervo at Albert Einstein College or Medicine or Thomas Seyfried at Boston College.

I did find this NIH article with Thomas Seyfried https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367849/ that states:
A program was developed (Glucose Ketone Index Calculator, GKIC) that tracks the ratio of blood glucose to ketones as a single value. We have termed this ratio the Glucose Ketone Index (GKI)…
The GKIC was used to compute the GKI for data published on blood glucose and ketone levels in humans and mice with brain tumors. The results showed a clear relationship between the GKI and therapeutic efficacy using ketogenic diets and calorie restriction.”

Did everyone else know and understand this except me??? It sure motivates me to build my “water fasting muscle” and FMD trials and do more of it.

I’d love others to check out the video, share their thoughts and check my understanding. If this is all for real, I’m thrilled to be able to get a sense of whether I have any autophagy going on and if so, at what therapeutic range. If I have arrived late to this party and everyone already knows about this, a simple “Yes, Virginia, there is a Santa Claus” will be fine! Thanks!

Noob wants to do a long fast
(Katie the Quiche Scoffing Stick Ninja ) #2

How very interesting.
I am book marking this, I ate last night so won’t have any decent numbers to calculate but I have been fat fasting since 11pm last night, i’ll need to wait another 12 hours before I check numbers. Thanks for posting :slight_smile:

(Bunny) #3

Some other interesting caveats and how to play head games with your doctor (just kidding don’t really do that)…lol

  1. “… One caveat here is that very low-carb diets will produce elevated fasting blood glucose levels. Why? Because low-carb diets induce insulin resistance. Restricting carbohydrates produces a natural drop in insulin levels, which in turn activates hormone sensitive lipase. Fat tissue is then broken down, and non-esterified fatty acids (a.k.a. “free fatty acids” or NEFA) are released into the bloodstream. These NEFA are taken up by the muscles, which use them as fuel. And since the muscle’s needs for fuel has been met, it decreases sensitivity to insulin. You can read more about this at Hyperlipid. So, if you eat a low-carb diet and have borderline high FBG (i.e. 90-105), it may not be cause for concern. Your post-meal blood sugars and A1c levels are more important. …” …More
  1. “… So, I often walk around with a fasting blood glucose of 5.9mmol/l and in mild ketosis, yet have normal pancreatic and muscle function, provided I carb load before the test. BTW my FBG dropped to 4.3mmol/l after three days of carb loading. That then raises the question as to whether Mark “iwilsmar” and myself are typical of LC eating people, or an oddity or two. This brought to mind the self selected macronutrient study performed on mice by Ortman, Prinzler and Klause. They allowed mice to select their own diet and, lo and behold, the mice chose (by calories, not weight!) 82% fat and 5.6% carbohydrate. Sensible mice. NB These German mice should each be given Professorships of Nutrition at medical schools in the most obese nations of the world. Quite what we should do with the current professors I’m not sure, but I bet the mice could think of something. Anyway, these mice are cool. The only thing that bugged me when I first read the paper was that they had a higher fasting blood glucose than those poor mice fed the normal junk which passes for laboratory mouse “chow.” This now fits in to an overall pattern. Elevated non esterified fatty acids induce physiological insulin resistance and a higher than expected FBG level. A simple switch to higher carbohydrate eating (in myself) allows the normal underlying pancreatic and muscle function to show. It also fits in with the FBG of 3.5mmol/l found in the carbohydrate fuelled natives in the Kitava studies. …” …More

Fasting Glucose 170!
Why do I have consistent high blood glucose readings while fasting?
(Barbara) #4

Bunny, it isn’t just the BS that is used during a fast, it is also the Blood Ketone level. Dr Boz is saying to divide the Blood Sugar result by the Blood Ketone result to arrive at a ratio that gives clues about the level of autophagy you have reached.

(Bunny) #5

Did a post here about something similar to Dr. Boz’s division ratios (BG & BHB):

Low ketones and lower BG levels could similarly demonstrate (crowd-sourced data) an optimal level of autophagy taking place?

How to use your blood sugar meter as a fuel gauge

Megan Ramos also has a wonderful description on BG levels and ketones that I posted here.

(Karen) #6

Don’t ha e a Mojo, but fascinating


(Barbara) #7

Thanks Bunny!

(Doug) #8

Interesting stuff, Barbara. Not sure how applicable the Glucose Ketone Index is to autophagy; not saying it doesn’t apply at all, but in humans I think the GKI would swing around faster than the rate of autophagy.

I think a case can be made for some possible autophagy toward the end of the first day of fasting. It’s mostly nutrient sensors that control it, and it takes a while for the stomach to empty, then for the small intestine to empty, for the ‘Post-Absorptive Phase’ (as Dr. Fung describes it) to finish, and for glycogen to be depleted. The Insulin/Glucagon ratio also affects it, and this gets more favorable for autophagy through quite a few days of fasting.

The “peaks at 3 days” thing is suspect, to me. A mouse has autophagy still increasing at 2 days of fasting, and the mouse is halfway or more to death from starvation at that point.

(Barbara) #10

I am happy to report, on my 2nd attempt at my hacked FMD, I’m getting ketones of 5 after one day and 7’s the remaining days. I plan to repeat this 5 day FMD/25 day refeeding for 5 months and hope I see some lasting benefits.


I recently listened to a Peter Attia podcast episode called “Nothingburger” where he fasted for a week, sandwiched between two weeks of keto.
Peter took lots of bloods pre, post and during this n=1 experiment.
His stated aim was in part to see if there was any biomarker that could indicate autophagy was occurring or had occurred.
The question has not been definitively answered but Peter did note a massive increase in his serum uric acid level following the 7 day fast.
As the only things that will put up se uric acid are increased ingestion of fructose, ethanol or protein, none of which he was doing as he was fasted,
Peter surmised that the rise reflected increased autophagy. The elevation was from breakdown of waste nitrogenous products from cells during autophagy.
Following fasting, the uric acid level returned to normal prefasting levels.


(Karen) #12

Could it have been muscle. Protein from his own muscles.?


He said he didnt think he lost any lean mass in terms of muscle mass, although that is subjective.
It was just an interesting observation and could well be a biomarker of autophagy.

(Jane) #14

Are you sure? Shouldn’t it be “insulin sensitivity”?

(Bunny) #15

You would have to ask Chris Kresser? I miss-linked on that post (too late to edit)…sorry about that!

Here is the source:

When “Normal” Blood Sugar Isn’t Normal (Part 2)

BTW: I think what he (Chris) is talking about or is referencing is physiologic insulin resistance (skeletal muscle tissue i.e. “glucose sparing?”) rather than pathological insulin resistance (hepatic e.g. NAFLD)?

Like in this chart here (…with a progressively lower HOMA-IR score your becoming “highly insulin sensitive”):

New Study: Prolonged Fasting Induces Physiological Insulin Resistance!
Protein consumption. Keto vs Zero Carb
Why do I have consistent high blood glucose readings while fasting?
(Lori Nehring) #16

I have listened to Dr Boz, and she has talked about how important it is to get at least 8 hrs of sleep a night and to quit eating early. I get up at 5:00 AM and have always been a night person (also have insomnia at times, awake until 3:00 AM - alarm off at 5:00 AM, get to work @ least 12 hr days. Over & over. I thought I was doing great😉)
I started Keto Jan 2, 2018. I lost 74.8lbs by Feb 2019, but had been stalled a few months up & down a few pounds. I am 60 years old, not diabetic, but have autoimmune problems. I still want to lose 60 more lbs. I was perplexed why I was stalled, as I was eating well within my macros. My morning Blood glucose was at times 114! I FINALLY decided I was going to REALLY try Dr Boz recommendation. She said your liver can’t flush and adrenals cant heal if you constant inundate them with “work.” SO, I quit eating at 5 or 5:30 EVERYDAY. Nothing but water passes my mouth. I make myself sleep by 9:00 PM, so I can get 8 hrs of sleep by 5AM. I have done this 2 days now. Yesterday upon rising, my BS= 88, KET=1.9, This morning BS=78, KET=2.5 = 31 ratio.
I’m so excited to see how this will help me. I notice, when I wake up, I am FULL of energy.
Try it. it hasnt been hard!
PS, It’s a Sunday, so I slept in a bit.

(Karen) #17

Are you losing weight? I find the ratio idea interesting. I get enough sleep and it’s pretty solid. I need to eat a bigger meal at 5:30. I’m getting hungry.

(Eric - The patient needs to be patient!) #18

Your Dr Boz ration is great. Your GKI ratio it is 78/18/2.5 = 1.73. https://perfectketo.com/track-your-glucose-ketone-index/

I go to bed between 8:30 and 9:00 most nights because I’m in the gym by 5 am. Some days, especially after 24hrs of fasting, the ketones wake me up early.

I’m trying to eat earlier but wife and I both work and we like to eat together. The social pressure results in later eating. But she is working into keto so maybe we can just agree that we will find a way to eat earlier or even eat alone.

Fasting has helped by BG go from 130 in the am to 101. During the day I have seen it be 85,95,103 recently. Ketones are usually 1.4 or so. I did have a day with much better numbers. I will have to go back and see in my logs when I finished eating the night before that day.

(Karim Wassef) #19

I use this method too but I ratio it down to a 0-10 scale and track it over months of fasting and keto. It works for me!

(Karen) #20

How much does testing cost? how often do you test?

(Eric - The patient needs to be patient!) #21


I use a keto mojo meter and the ketone strips are $1 and the BG strips are 10 cents. I took several baseline measurements with IF 18/6 and similar and some with a few EF at 26 hrs.

Now I will measure when I exceed 26 hrs significantly. I’m interested in some of my extended fasts being strong autophagy fasts so I want to get my Dr Boz Ratio to below 40 or my GKI value to be <2.2.

So tomorrow I will get to at least 48 hours and will measure at 48. TOmorrow I don’t have the luxury of pushing beyond 48 for social / family reasons. But next week if I’m not near or below 2.2 GKI I will just fast longer. At least that is the plan.

It is not yet easy for me to get there because my BG still wants to be slightly elevated even at 36 hrs fasted I have seen it at 101. I have also seen it at 80. BTW - Yes I am <20g carbs. My gluconeogenesis engine wants to generate more glycogen than I need.