Brain Health,

#147: Ketosis and Your Brain

September 23, 2016

There was a time not so long ago when nutrition was simple:  carbs good, fats bad.  But since this neat summary was from the same people who told us to eat more margarine and fewer eggs, well, let’s just say that advice wasn’t the most accurate.

Welcome to the ketogenic diet.  A high fat, low carb diet based on how our ancestors probably ate, it can control epilepsy, help you get a leaner body, and make your thinking clearer and sharper.

Dr. Dominic D’Agostino, Associate Professor of Molecular Pharmacology and Physiology at the University of South Florida and Senior Research Scholar at the Institute for Human and Machine Cognition (IHMC), is here to talk to us about what exactly is going on in your body on a ketogenic diet.

The Evolution of Human Diets

When you think about how our caveman ancestors lived, they didn’t have access to a glut of high glycemic load foods like ripe fruit or honey, and they definitely weren’t snacking on white bread.

They were eating a diet high in fiber and fat, and low in carbs.  They were also probably in ketosis for most of the year.

Cognitive Benefits of a Ketogenic Diet

When your body is in ketosis, your brain just works better:  you’ll feel more lucid and sharp.

Like so much about the brain, we don’t know exactly why this is.  But from an evolutionary perspective, it makes sense.  If you haven’t been successful in getting food, it’s time to make a new plan, and you more likely come up with a successful one if your thinking is clear and sharp.

Getting into Ketosis

Ketosis is a metabolic state in which your brain and body’s energy comes from ketone bodies, instead of from glucose.

There are a few ways of pushing your body into ketosis, including sustained periods of fasting and following a ketogenic diet (as the name so obviously suggests).  Dr. D’Agostino also suggests spending some time in the sun and heat.  Getting out in the sun lowers glucose and raises ketones, and can push you into ketosis, especially if you’ve been fasting.

How will you know if your body has gone into ketosis?  You’ll want to check your level of ketones daily, at about 3 or 4 pm.

You can buy blood tests to accurately measure your ketones level.  But if you want to save money, just grab some cheap ketone pee sticks at any pharmacy for about $0.25 per strip.  They’re less accurate but will still confirm whether or not you’re in ketosis.

If your results from the urine strips are at least 15-40mg / dL, you’re almost definitely in ketosis.

Another way to check if you’re in ketosis is to ask someone to smell your breath.  Acetone (that stuff in nail polish remover) is a ketone body, and some people in ketosis find that their breath starts to smell like acetone.

Psst…  If this happens to you and it’s affecting your dating life, try drinking lots of water, coffee, and green tea, and chewing sugar-free gum.

Going Keto:  What to Expect

First, a quick explanation of what a ketogenic diet is.  The classic ketogenic diet is comprised of 85-90% fat, much of it dairy fat.  Realistically, this is really hard to sustain.  So, Dr. D’Agostino tends to follow a “modified” ketogenic diet of 65-70% fat with much of the dairy replaced with fats from things like coconut cream and avocado.

So when we refer to a “ketogenic diet,” we’ll be talking about a modified ketogenic diet.

If you’d like to try a ketogenic diet, the best way is to ease into it.  If you’ve been eating a high-carb diet, your brain is probably hooked on glucose, and if you cut out glucose too suddenly, you could have some fairly unpleasant withdrawals, with flu-like symptoms.

Dr. D’Agostino’s recommendations:

  • Eat 100 grams of carbs per day, split up into portions of 25 grams.  This is low carb enough to start to get the metabolic benefits of a low carb or ketogenic diet.
  • Make sure that, along with those carbs, you’re getting 150-200 grams of fiber, so the carbs won’t cause blood sugar level spikes.
  • Every two or three days, eat a ketogenic diet and add MCT oil.

Ketosis and Intermittent Fasting

Ketogenic diets and intermittent fasting aren’t the same thing.  A ketogenic diet governs what you eat, and intermittent fasting rules when you eat it.

That said, the two are complementary.  Intermittent fasting is easier to maintain when your brain and body are keto-adapted.  Depending on the length of your fasting period, practicing intermittent fasting can also nudge your body towards ketosis.


Ketosene by VitaMonk

Ketosene is a fast-acting exogenous ketone supplement that helps to speed you into ketosis and ease your metabolic transition with clean energy. Includes an ideal blend of magnesium, calcium and sodium BHB (goBHB™ beta hydroxybutyrate) -- plus many other essential nutrients often depleted during ketosis.

Supplementing For Ketosis

Taking the right supplements can help you get into ketosis and make sure your body is functioning at full capacity in that state.  Here’s what Dr. D’Agostino recommends:


Show Notes
  • 00:00:36

    Ketosis and the brain

  • 00:02:17

    This Week in Neuroscience: Smarter Brains are Blood-Thirsty Brains

  • 00:07:30

    The audience interaction section

  • 00:08:47

    Next #AxonChat - Wednesday, September 28 at 8pm Eastern Time with Dominic D’Agostino

  • 00:09:36

    Quick background on ketosis (check out Episode 56: Ketosis vs Cancer? for more of a primer)

  • 00:14:12

    Dr. Dominic D’Agostino’s entry point to researching ketosis

  • 00:18:59

    What can ketosis do for cognition?

  • 00:19:55

    Ketone bodies in different ratios

  • 00:24:09

    Is living in ketosis ‘normal’?

  • 00:28:47

    Optimising metabolism and preserving mitochondrial function through ketogenic dieting

  • 00:32:33

    Ketones versus glucose for your brain

  • 00:38:39

    “Keto flu”, heightened focus, and other physiological and cognitive responses to ketosis and fasting

  • 00:41:58

    The difference between male and female responses to ketosis

  • 00:44:29

    How should you aim to be in a proper state of ketosis?

  • 00:46:29

    Factors other than food that affect ketone levels

  • 00:47:55

    The effect of ice water baths and direct sunlight on glucose levels

  • 00:50:57

    States of mind during a fast versus a ketogenic diet

  • 00:55:54

    Intermittent fasting versus longer periods of fasting

  • 00:57:40

    The importance of sodium and magnesium during ketosis

  • 01:01:20

    “Ketone breath”

  • 01:02:38

    What is the best time to check blood ketones?

  • 01:05:25

    Ruthless Listener-Retention Gimmick: Well-timed exercise might improve learning


  1. Great conversation here. Appreciated the heads up regarding the heavy use of jargon, which was a bit over my head at points, but a very helpful discussion none the less. I was shocked to hear Dominic reference that too much caffeine could potentially pull someone out of ketosis. Very curious at what amount it could do so?

    1. Jesse Lawler says:

      Thanks Michael! Yes, good point that I wish I’d followed up on. We’ll be having our “Axon Chat” with Dr. D’Agostino on Twitter in just about 24 hours from now, so I’ll follow up with this then — unless you’re there and beat me to it. 🙂

  2. Giuseppe cocilovo says:

    Hi Jesse I didn’ t understand how many days per week One should go for a ketogenic diet, and is it one day enough to enter into kethosis?

  3. Shaptukaev says:

    That was really interesting and useful information. But I wanted to ask you about what Dom said at time (52min). What does he mean,when he says 1 mml increase is about 10% increase of substrate to the brain? Is that (same glucose amount in brain) + (typical ketone amount in brain)+ and 10% more? Or does it substitute glucose? And if it is so, does the brain use that energy or does it just stay around the brain without being used? I know we can’t know for sure, but it would be helpful if you said what you think. Thanks in advance!

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