Over the last week I’ve documented my progress into nutritional ketosis through a ketogenic diet. Yesterday, I added intermittent fasting to that process. Here are the results.
As most of you know, I have advocated for low carb high fat nutrition to reverse metabolic disease since I began practicing it myself in 1999. My understanding of this powerful tool has grown both with my personal experience of it and with the growing body of literature helping to explain the nuances we should all understand. Over the last three years intermittent fasting (IF) has come into it’s own in large part due to the influence of Jason Fung, MD author of The Obesity Code and The Diabetes Code, both books I highly recommend to my patients. I have adopted IF as a personal routine over the last year and have found it extraordinarily powerful at improving my health and well-being.
There are many different ways to undertake fasting ranging from time restricted eating (TRE) to prolonged fasts. TRE is simply not eating for about 12 hours in every 24 hour cycle such as not eating after dinner until breakfast the next day roughly 12 hours apart (8pm to 8am). Most studies don’t consider this true fasting as many of the genes and benefits of fasting are not measurable until one reaches 14-16 hours of fasting.
Intermittent fasting therefore is usually anything lasting 16 hours or longer with the remaining hours used as an opportunity to feed. A 16:8 protocol is nothing after dinner at 8pm until noon the next day. A 20:4 protocol is nothing between 8pm and 4pm the next day. I recommend many of my patients undertake a 24 hour fast weekly or every fourth day depending on the goal. Again, I stress, please don’t undertake this without talking to me first as many times patients need their medications reduced or altered to avoid being over treated during the fasted state.
Yesterday I undertook a 24 hour fast which ended up lasting 27 hours due to the timing of my dinner meals on Monday and Tuesday. Monday night I ate a quick meal of roasted chicken, blueberries, and macadamia nuts then went to exercise around 5:30pm. I didn’t eat again until Tuesday night at 8:30pm. Tuesday’s dinner of 1/2 of chicken, an avocado, and cheese was 5 net carbs.
Throughout the day I followed my glucose levels on my Libre and my blood ketone levels on my KetoMojo meter. As you can see from the Libre readings below, my glucose levels were exceedingly stable and slowly declined throughout the day to a nadir of about 69 mg/dL right before dinner. My meal didn’t budge that number at all.
The ketone readings steadily climbed to some very nice levels throughout the day and have stayed higher than last week even after I’ve eaten several times today. Starting out the day at 1.0 mmol/L they climbed to 1.7 mmol/L by lunch time, 2.7 mmol/L by the end of work, and 3.1 mmol/L by the time I broke the fast at dinner.
Beneficial ketone zones after an overnight fast should be around 0.5 mmol/L or higher. They are are optimal around 1.5-2 mmol/L while eating a long term ketogenic diet. After a prolonged fast they can be around 3-5 mmol/L.
When I fast I tend to feel better and better as the day progresses. The initial hours can be challenging but as the ketones develop the desire for food all but fades to zero and hunger is non-existent. I really enjoy that freedom. The clarity of thought and presence of mind that comes in this state is one of the main benefits I desire from fasting. It brings me back to it again and again and I find myself looking forward to the next day of fasting.
If you’re interested in learning how to use nutritional ketosis, intermittent fasting, or a continuous glucose monitor for its health benefits give me a call. We’ll walk through the process together to ensure your success and safety.