Here's What Happens Inside Your Body When You Start Keto!

Special Thanks to my team and Nicholas Norwitz - Oxford Ketone PhD Researcher and Harvard Med Student - for working diligently on research as well!

Here's What Happens Inside Your Body When You Start Keto - Thomas DeLauer

How Does Ketosis Start in the Body?

Fundamental Principles:

1) The brain can use glucose or ketones as fuel, but not fat
2) The liver stores 600 calories of glycogen (glucose) to defend blood sugar, whereas the body contains almost an unlimited reserve of calories in the form of fat
3) Glucose can be made from lean (muscle) tissue through gluconeogenesis
4) Insulin inhibits fat mobilization and ketogenesis

Despite weighing only 3 lbs, your brain consumes 500 kcal per day. For most people, this energetic demand is met entirely by glucose that comes either directly from the diet or from the stored form of glucose (glycogen) in the liver. Your brain can’t eat fat.

Since your brain burns 500 kcal per day, and your liver stores only 600 kcal of glycogen (and muscle glycogen cannot be used to defend blood glucose), after about one day of fasting – or a slightly longer period of carbohydrate deprivation – your liver runs low on glycogen.

At this point, your body should be forced to make a sacrifice: Lean (muscle) tissue can be converted into glucose through gluconeogenesis. Therefore, your body should be forced to break down muscle tissue to feed your brain’s requirement for glucose.

But there’s a twist. Evolution wouldn’t tolerate this sacrifice. If our ancestors had to break down lots of muscle tissue every time they were deprived of food, we would have gone extinct. Evolution found a work around: ketones, which are an alternative fuel for the brain.

Initiation of ketosis can be conceptually summarized as follows: Insulin is released in response to carbohydrates. Insulin (1) promotes fat storage/inhibits fat mobilization and (2) inhibits ketogenesis.

Therefore, when you restrict carbohydrates (and excess gluconeogenic protein) and your insulin goes down, your body begins to burn fat and takes the breaks off of ketogenesis. Your body then presses down on the accelerator for ketogenesis once your liver glycogen stores are depleted and your brain demands more fuel.

At the cellular level: Free fatty acids (FFAs) are transported into liver cells through the CD36 transporter. Long chain fatty acid-CoA synthetase (LCFACS) adds a CoA group onto FFAs to make fatty acyl CoA (FA-CoA).

This FA-CoA is transported into mitochondria by the carnitine shuttle system, which requires carnitine, the transporter carnitine acylcarnitine translocase (CACT), and the enzymes carnitine palmitoyltransferase 1 and 2 (CPT1 and 2).

The long FA-CoA carbon chain is then broken down into two-carbon acetyl-CoA (Ac-CoA) chunks by β-oxidation. These Ac-CoA chunks are converted, via two enzymes – HMG-CoA synthase (HMGCS) and HMG-CoA lyase (HMGCL) – into the ketone body acetoacetate (AcAc).

AcAc is then converted into the storage form of ketones, β-hydroxybutyrate (βHB), by βHD dehydrogenase (BDH). βHB is then exported from the mitochondria and from the liver cell by monocarboxylate transporters (MCTs) into the bloodstream, from where it can traffic to peripheral tissues or the brain.

Once at its destination, βHB goes into the cell via MCTs and is converted back into the ketone body AcAc by BDH. AcAc is then acted upon by the rate limiting enzyme of ketolysis, succinyl-CoA:3-oxoacid CoA transferase (SCOT), and then acted upon by acetyl-CoA acetyltransferase (ACAT) to generate Ac-CoA.

Ac-CoA is the convergence point of glucose, fat, and ketone body breakdown and enters the Krebs Cycle to be completely oxidized/broken down into carbon dioxide.

Special Thanks to Nicholas Norwitz - Oxford Ketone PhD Researcher and Harvard Med Student:

[Nedsped]

I can always count Thomas for making me feel good doing keto, to me you are like the motivational speaker of keto 😄

[HairVolution]

Can we talk about the fact that he's just speaking freely with all of this knowledge and no video cuts? Amazing.

[HEATHERRSE]

Did you see the trending news report that came out yesterday claiming they were wrong about limiting the consumption of red meat??? Would be a great video topic for newbies to keto. I used to limit beef, steaks because of what came out 5 years ago! Glad we are all getting on the same page now 💪

[koko_-ejvo]

IS AWESOME HOW GOD THOUGHT ABOUT EVERY LIL THING IN OUR BODY'S🙌🙏 AND THANK U THOMAS FOR UR LOVE AND TIME TO EXPLAIN THE MOST EASY WAY ALL THE TIME❤

[richiebox]

Thomas your are the king of keto and I'm sure everyone will agree. I've lost 28lb in 8 weeks because of listening to your videos. I will keep sharing your knowledge and thank you for helping to turn my life

[liziya]

Who else got reminded of the magic school bus when that little bus was going through the body 😂🚍

[chrisbessey]

Anyone else doing sober October? Gonna go the next level with exercise and nutrition too! Let’s do it!

[PurpleAvenger]

Been on keto for a week and a half and ive already dropped 7lbs! Thanks Thomas!

[ceciliajimenez]

Loving the illustrations and wording so I can understand!!

[LWags]

I’ve been doing Keto/ IF for 2 months and feel great!

[wyel]

Now I want to see an episode of The Magic School Bus on ketosis. Thanks Thomas.

[DweezlePeePants]

This is absolutely one of the best keto videos out there. Thank you SO much for every video you do.

[antonioperez]

Thomas. Love the ENERGY, I can feel the vibe Brother. Sounds weird but I can. I’m new to science & ketones but with fasting & high intensity exercise or even single leg squats that I thought I’d never do (Calisthenics) I gained strength shape energy knowledge & better science based healthier ways of living. I want to take the time to say THANK YOU BRO. 💪🏾💛🤘🏾🔥🔥🔥

[KenSaylor]

Excellent video. Thomas, can you give a talk on what happens when you exit ketosis. I'm almost to my target weight, do I change my 75 20 5 to about 55 35 10? Much of the videos focus on being in Keto. We need help where to "live" after keto or maintaining after weight loss goals. And blessings to you and yours as always.

[Southernburrito]

8:14 paused. Hold up Tom, I want Scooby to drive the van. You said you'd make it fun.

[feircephoenix]

I'm fricken freezing and nose is running...My body and breath is warm....Having a hard time sleeping but if this is ketosis then that's great

[grampathebiohacker]

Hi Thomas! love your videos! Just to say can you do a video on the difficulties of doing keto/fasting in a cold climate/Fall season? Cheers

[myrhev]

Just came off of keto recently. Had been on keto for roughly three months, give or take a week. I loved the diet. Blood sugar was great and I finally got control of my appetite. So why did I come off of it? Anxiety.

My anxiety and panic attacks have slowly ratcheted up over the last three months. In the last week or so it has been ridiculous to the point that my meds and breathing techniques weren’t working.

Came off of keto and it is like night and day. So, am I blaming keto for my panic attack issues? Possibly. I really don’t know what caused it. I was eating leafy greens, but maybe I had some form of vitamin deficiency. I don’t really know what caused it. I just know that coming off keto has gotten me almost back to normal. Sadly, being back to normal means craving sweets again.

[melissaanne]

We just found out our 20 year old special needs son has Glut 1 deficiency which means glucose can’t pass the blood brain barrier. The only treatment is a keto diet. We’re working on it and it’s a big adjustment for him. Doc said when he is not in ketosis his brain is basically starving.

[catemaclean]

This could be a Magic School Bus Episode. LOL