The Randle Cycle: How Your Body Chooses Between Glucose and Fat with Dr. Ben Bikman

In this episode of The Metabolic Classroom, Dr. Bikman introduces the concept of the Randle Cycle, also known as the glucose fatty acid cycle, in a lecture aimed at providing a better understanding of metabolism. The Randle Cycle, first identified by Dr. Philip Randle and his colleagues in the 1960s, explores how cells decide between using glucose or fatty acids for fuel. Dr. Bikman emphasized that this cycle has been misinterpreted on social media and aims to clarify its relevance in metabolic functions and nutritional decisions.

The Randle Cycle explains the competition between glucose and fatty acids as fuel sources at the cellular level. When more fatty acids are available, cells will primarily burn fats, and when more glucose is available, they will shift to burning glucose. Dr. Bikman detailed the biochemical pathways involved in this process, such as how increased fatty acid oxidation produces molecules like acetyl-CoA and NADH, which inhibit glucose utilization. Conversely, increased glucose levels lead to the production of malonyl-CoA, which inhibits fatty acid oxidation by preventing fats from entering the mitochondria.

Insulin plays a critical role in determining which fuel the body uses. High insulin levels promote glucose utilization and inhibit fat breakdown and burning. In the absence of insulin, as seen in untreated type 1 diabetes, the body cannot stop burning fats despite high glucose levels. This uncontrolled fat burning leads to the production of ketones, which are used by the brain and other tissues. Dr. Bikman highlighted the importance of insulin in maintaining metabolic flexibility, allowing the body to switch between glucose and fat burning as needed.

Dr. Bikman also discussed the implications of the Randle Cycle in diabetes. In type 1 diabetes, the lack of insulin results in high levels of both glucose and free fatty acids, with the body predominantly burning fats. In type 2 diabetes, characterized by high insulin levels and insulin resistance, the body becomes "metabolically inflexible," often remaining stuck in glucose burning mode. This inflexibility contributes to the various metabolic issues associated with type 2 diabetes.

Finally, Dr. Bikman touched on the impact of insulin resistance on the brain's fuel choices, noting that the brain primarily uses glucose and ketones. Insulin resistance in the brain can impair glucose uptake, leading to a compromised energy state and potentially contributing to neurological disorders. The lecture concluded with an emphasis on the critical role of insulin in regulating the Randle Cycle and maintaining overall metabolic health.

00:00 - Introduction to the Metabolic Classroom and Dr. Ben Bikman
01:00 - Overview of the Randle Cycle (Glucose Fatty Acid Cycle)
02:00 - Historical Background: Philip Randle’s Research
03:00 - Experimental Model: Perfused Rat Hearts
04:00 - Key Terms: Glucose and Fatty Acids
05:00 - Concept of Substrate Competition
06:00 - Reciprocal Inhibition: Fats vs. Glucose
08:00 - Fatty Acid Oxidation Process
10:00 - Biochemical Pathways: Acetyl-CoA, NADH, and Pyruvate Dehydrogenase
12:00 - Role of Citrate in Glycolysis Inhibition
14:00 - Glucose Utilization and Malonyl-CoA
16:00 - Insulin’s Role in Fuel Selection
18:00 - Insulin’s Impact on Glucose and Fat Burning
20:00 - Diabetes Case Study: Type 1 and Type 2
22:00 - Type 1 Diabetes: High Glucose and Fatty Acids
24:00 - Ketones Production in the Liver
26:00 - Type 2 Diabetes: Insulin Resistance and Metabolic Inflexibility
28:00 - Insulin Resistance in Fat Cells
30:00 - Metabolic Inflexibility in Type 2 Diabetes
32:00 - Insulin Resistance in the Brain
34:00 - The Impact on Hunger and Neurological Disorders
36:00 - Conclusion: Importance of Insulin in Metabolic Health

#Metabolism #RandleCycle #DrBenBikman #InsulinResistance #GlucoseMetabolism #FattyAcidOxidation #MetabolicHealth #DiabetesResearch #Ketosis #Type1Diabetes #Type2Diabetes #InsulinRole #CellBiology #NutritionalScience #MetabolicFlexibility #Ketones #GlucoseUtilization #FatBurning #BiomedicalScience #HealthLecture

References:

[johntatman]

I envy your students having you as their professor. I can not imagin anyone who could make complex topics more easily understood. You do this in a very informative way as well as entertaining. I typically need both oral and visual aids to learn however I find I have no need for visual diagrams when your teaching. I so hope you never stop these videos!!

[dromlakhani]

I am an Endocrinologist and this is brilliant!

[MichaelTyner-ze]

as a physician who tries to explain metabolism to many patients, this was a great description of a complex problem.

[zorinaganpaul]

FINALLY!! Thank you Dr Bikman for this deep dive. The Randall cycle has been invoked so often by influencers with little knowledge that it left my head spinning. I have clarity now ❤

[balabani]

I am an electronic communications systems engineer and I am amazed at the clarity by which Dr. Bikman explains the Randall Cycle and the function of insulin in different types of cells like brain, liver, muscle and fat. My hat is off to you Dr. Bikman.

[petejandrell]

I listen to these lectures as I do my morning exercising and find that the 8th or 9th listen is probably where I start getting a fuller picture and the info starts to 'stick'. Well worth the effort and thanks Dr. Bikman.

[CynCopeland-TheAnswerIsMeat]

Most of the references to the Randall Cycle I've heard 'bandied about' really push hard on the logic of 'don't mix your carbs and fat' (or you'll get fat) - if I've understood this lecture and the topic properly, it's really just about appreciating that if you load up on pasta with heavy cream, the fat in that meal will not be a) necessary for fuel or b) be able to burn it until such time as the glucose is used up, insulin has dropped and the body demands energy and uses fat. For folks who eat three 'mixed' meals per day (plus snacks), their body won't likely be needing fat for fuel, ever. Obviously, eating this way will contribute to the issues we see with regards insulin resistence, diabetes, obesity (that fat needs to go somewhere!). A very informative lecture Dr. B!!! ❤

[szghasem]

Talk about riding on the shoulders of giants. Thank you, Dr. Bikman, for this incredible ride. 😊

[kristaG]

I have read dozens of books on this topic, subscribe to multiple channels and have favorite website searches. I always go to Dr Bikman to wrap it up in a way that seals it in my head. Great, great teacher and helper of humanity.

[rajeevarora]

Dr. Bikman is a rare gem of a teacher! He explained the Randle Cycle and more in this class very simply and clearly! Wish I was part of his class.

[PaulaAlinsangan]

Do you know that you have a 77-yr old student in your class? Yes, you have, and that's me. And I do learn a lot from your lectures - Randle cycle, lectins and of course insulin. Thank you very much Dr. Bikman.

[frodemansika]

I have followed Dr Bikman for some months now, and my daily work as an heartfailure nurse, has given me an incredible help to understand the metabolic problems many of my patients are suffering from. Keep up the good work Dr Bikeman. This knowlegde that you present is very importen and will probaly change the way traditional health system are thinking and working.

[retiredbitjuggler]

I am a layman and have been missing a few links to allow me understand the underlying mechanisms that influence hunger and insulin resistance. I have been trying to find the answer for the past 2.5 years and stumbled on this lecture which just switched a light on. It is so easy to understand, so why is it you are the only one I have found that distilled this into such a simple construct? Thank you for that! I switched to an OMAD lifestyle 2.5 years ago with miraculous results, but have been perplexed by not knowing why I feel little to no hunger daily, or during my periodic 3 or 4 day fasts (with the same near zero level of hunger). People around me simply believe that I’ve lost my mind because I couldn’t explain how that is possible. The answer was right in front of me — my daily mission is to suppress the production of insulin. I don’t measure my keytone levels (my interest is peaked, so I may start), but I suspect I probably maintain a fairly good level. I think I may have the missing link that might allow me to cast a light on my non-believers. 😊😊😊 Thanks again!

[sangitayadav]

I have read many books, I listened to many Youtube videos by many of the worlds leading gurus and health experts but nothing came close to the hidden herbs by anette ray. I recommend everyone giving it a read.

[fronniebealer]

I wish I had known about your lectures and teaching style when I was still teaching. I could have helped my students so much more.

[YourTechOnLine]

As an elder, deeply interested in the metabolic reality of humans, your information is spot on in my opinion. Your willingness to share your passion with mostly normal and less informed individuals, is a blessing to all who will hear, hopefully understand, and integrate into their lives to become healthier individuals. Thank you.

[Trthsker]

I totally understand now, why I didn't understand the Randall Cycle fully, until your brilliant explanation.Thanks.

[michaelsliwinski]

My 10 year old grandson has very recently been diagnosed as type 1 diabetic. Your lecture has been very interesting and informative. Thank you!

[YELLOWFROGdesign]

Thank you for the lecture! I am learning so much about my T2D! I went from a 10.8 A1C to a 6.2! We are blessed to have teachers like you. G-d bless you!

[JRBunch]

Thank you for this, as a former road cyclist the understanding of muscle tissue types, Krebs cycle and so on has led me here today. It looks like glucose intolerance has entered my life maybe my own doing. Just wanted to say your lectures are very informative and easy to understand.