Husband of one, father of six, grandfather of 14. Chancellor Emeritus, SMUG. By day I'm the Director of the Mayo Clinic Social Media Network. Whatever I say here is my personal opinion, and doesn't reflect the positions of my employer.
Despite having two tablespoons of heavy whipping cream in my morning coffee, twice each day, I achieved 27 hours of Glucose Ketone Index (GKI) <1, and at least 85 hours of GKI<3.
Results were close to what I did with water-only, and my different exercise pattern explained some of the lag in getting to my GKI targets.
My wife Lisa did the same fast, and her results were even better:
She had GKI<1, the highest therapeutic level, for 60 hours, and has had GKI<3 for about 100 hours as I write this.
As my daughter-in-law would say, Lisa smashed my face!
Note also the significant difference between her results on the coffee and cream version of the fast as compared with the water only.
Some key observations:
Her GKI was much higher at the start of the water-only fast. This was because her last meal before that fast was taco salad with chips, along with two cinnamon rolls with frosting.
In the coffee and cream fast, by contrast, she was in nutritional ketosis from the start, and was below 3 on the GKI at just 16 hours, a full 10 yours earlier than on the water fast. She reached GKI<1 at 25 hours, almost a full day ahead of what she had done in January on the water-only fast.
The big lesson here is that coming into a fast already in ketosis dramatically improves the results, to the point that even with up to four tablespoons of cream per day her readings were far better than those when she started a water-only fast from a high-carb state.
Importantly, we supplemented magnesium and sea salt daily throughout the fast to keep electrolytes in balance, and broke the fast with a small meal of scrambled eggs, bacon, cream cheese and guacamole to prevent refeeding syndrome.
Lisa and I both found this fast immeasurably easier than a water-only fast, both because of the taste of cream and also because we didn’t get the caffeine-withdrawal headaches.
We may try a black-coffee version of the fast sometime, but with results like this that are relatively easy I think including a little cream will be our standard practice for the preventive fasting.
Check out My Health Journey for the full story of our health improvements, and my #BodyBabySteps for an approach to how I would do it if I were starting today, based on what I’ve learned.
I have undertaken several extended fasts for cancer prevention, and in January Lisa joined me for our first joint #3DayCancerPreventionFast.
Because we wanted to ensure that we were reaching the optimal therapeutic level of ketosis, we did a water-only fast that first time.
To gauge the fast’s effectiveness, we took blood glucose and ketone measurements several times each day using our Keto-Mojo meters, which provided a Glucose Ketone Index (GKI) score.
On a Standard American Diet (SAD), ketones are essentially nonexistent because glucose levels are high, and therefore insulin levels also are elevated. The liver produces ketones from fatty acids in the bloodstream, but this only happens when insulin levels are low enough to allow fat cells to release the fatty acids.
Professor Thomas Seyfried developed the GKI score to compare the levels of glucose and ketones in the bloodstream. A GKI less than 3 is considered a high level of therapeutic ketosis, while the highest level is <1, which is what Seyfried seeks to achieve in studies treating cancer patients.
Since Lisa and I are seeking to prevent cancer instead of treating it, we decided to set two GKI targets on our #3DayCancerPreventionFast:
At least 72 hours with GKI<3 (High Level)
At least 24 hours with GKI<1 (Highest Level)
In our January water-only fast we easily met those goals, as I had 44 hours of GKI below 1 and more than 70 hours below 3.
Lisa and I completed another three-day fast on Tuesday, but this time we allowed ourselves coffee with two tablespoons of cream, twice per day.
If we could make this accommodation while still reaching our GKI targets, this would make our monthly three-day fast much easier.
Here’s a graph of my GKI values for the water-only fast (blue line) as compared with the coffee + cream fast (green line):
One additional difference between the two fasts is that the first time I did an intense cardiovascular workout at about the 18-hour mark, while for the second I ran two miles when I was 26 hours in to the fast.
Both had the effect of raising blood sugar levels in the short term, breaking down liver glycogen in the first instance and through gluconeogenesis in the second, while also burning some of the ketones I was already generating.
Because I burned the ketones during my run they were no longer in my bloodstream, which temporarily boosted my GKI. This meant that in the second fast I was delayed by about 7 hours in getting below 3 GKI.
Still, I reached a GKI of 3 at the 36-hour mark, and stayed well below it for the next 64 hours. (In fact, my GKI this morning was 1.5, so I’ve had 76 hours so far in high-level therapeutic ketosis, and I had 27 hours below 1.)
Here’s a comparison of my ketone levels over the course of both fasts. Another key difference is that this time I went into the fast with higher ketone levels.
Three Lessons and a Caveat:
Lessson 1: It’s good to start a fast already in dietary ketosis. For this week’s fast I was at GKI of 4, while I was at 15.3 when I started the water-only fast in January.
Lesson 2: Intense cardio the morning after beginning a fast is better than doing it later in the afternoon. It burns through liver glycogen and accelerates progress of the fast.
Lesson 3: Starting in ketosis and having a small amount of cream with coffee made this fast pretty easy. I really wasn’t very hungry, and I didn’t have caffeine withdrawal symptoms.
Caveat: I don’t know that GKI<1 for 24 hours and GKI<3 for 72 hours are the right targets. Given the purpose of our fast, to accelerate autophagy in healthy cells and to put serious stress on (and hopefully kill) any cancer cells by depriving them of glucose, those seem reasonable to me. If you think different targets are appropriate, I’d like to hear your reasons in the comments below.
What’s next? When we do this again in April, I will plan to be sure I’m well into dietary ketosis as I’m starting the fast, and will do the intense cardio exercise early on the first morning.
Tomorrow I’ll share Lisa’s experiences in the two versions of the #3DayCancerPreventionFast.
They’re doing really well: he’s lost 26.2 pounds and she’s lost 14.4, or 8.8 and 4.8 pounds per month respectively.
It hasn’t always been easy, but she had a pretty amazing and encouraging breakthrough a little over a week ago which showed just how much progress she has made.
Not only or even mainly in weight loss, but in her reorientation toward food.
After hitting something of a plateau, she decided to try going for a longer fast than what has become her customary 24 hours. By waiting to break her fast until the next morning, she could stretch to 36 hours.
But as it turned out, she was busy in the morning and didn’t get to eat until about 2:30 p.m. So her fast ended up being…
Then just a couple of days later, she forgot she had meetings until 8 p.m., and so added an “accidental” 36-hour fast closely following her nearly two-day fast.
Three months ago she would not have believed this was possible.
She also was amazed that at the end of a 36-hour fast she would have such “great clarity and energy.”
The alternate-day fasting, eating dinner to satiety every evening but skipping breakfast and lunch on alternate days, helped her to overcome a habit of unthinking late-night eating.
As she has become fat-adapted and also more mindful of the importance of a narrower eating window, she stumbled into two fasts that were both longer than what she had planned.
At some point, when he and she have reached their goals, we’ll have an online “coming out” party for them, complete with before and after photos and their whole story.
That hidden epidemic he describes is insulin resistance, sometimes called metabolic syndrome, which raises the risk of a host of diseases, from cardiovascular diseases, to various cancers and even Alzheimer’s.
Dr. Sarah Hallberg, one of my Health Sherpas, says patients who want to reverse type 2 diabetes have three medically proven options, backed by multiple published studies:
Very Low Calorie Diet
Low Carbohydrate Diet
Bariatric Surgery works for many people, with 30% or more able to achieve long-term remission. It also has the obvious downsides of surgical risk and expense. But it should be presented as an option, and some people will find it right for them.
A Very Low Calorie Diet, depending on the study, ranges from 300 to 1,800 calories per day. While these work really well in the short term, there is an issue with weight gain after the period of calorie restriction ends. It’s difficult to maintain the weight loss: the faster you lose weight, the faster you tend to regain it, and progress on diabetes can be lost too.
Low Carbohydrate Diets – Dr. Hallberg points to 22 randomized controlled trials (RCTs), 10 meta-analyses and 10 non-randomized trials, including six studies of two years or longer, including the Virta Health/Indiana University Health study she leads.
I think it’s worth watching the video below in its entirety for context, but if you want to skip ahead, she starts describing her results at about the 16:00 mark:
These results are phenomenal: Half of patients maintaining diabetes reversal at two years.
As she says, can you imagine if a drug had that kind of sustained effectiveness?
Here’s how the methods compare in blood sugar control:
In HbA1c, low carbohydrate is better than sleeve or very low calorie at two years, and equal to bypass.
And here’s how they compare from a weight loss perspective:
As Dr. Hallberg pointed out, the patients in her study (the purple line) started at a higher weight, and the average time with diabetes before the study was 8 years. Shifting the purple line’s starting point down 10 kg would make it pretty similar to either of the surgical options.
I greatly admire Dr. Hallberg and her collaborators, and I think the work Virta Health is doing is outstanding. Their results are great, and I think their intensive coaching intervention is valuable for people adopting this new way of eating.
I would add a fourth approach that I think will be the most effective, however: a combination of a low carbohydrate diet with intermittent fasting.
It conceptually combines the effects of the purple and orange lines in the graphs above.
Dr. Jason Fung calls fasting “medical bariatrics.” It has the benefits of bariatric surgery without the surgical expense and risk. It’s a lot easier to undo, too: You simply resume eating.
In fact, you have unlimited flexibility in adjusting the dosage of fasting. You can start with a 12-hour eating window each day, or you can fast for 16 or 18 hours and only eat from noon to 6 p.m. or noon to 8 p.m.
Low carbohydrate eating makes those fasting periods much less difficult, because fat and protein are more satiating than carbohydrates.
It’s kind of magical how these two strategies work together.
One final observation: At about the 23-minute mark of the video, Dr. Hallberg makes a really important point about the misplaced emphasis on randomized controlled trials in gauging efficacy.
RCTs are important when you have a drug intervention, because you’re typically testing a drug vs. a placebo, and the only thing you’re asking of the patients in the study is to just be sure they take whichever pill is assigned.
Diet is different. Motivation matters.
So does belief. If you’re randomly assigned to a diet for purposes of a study, even if you’re really motivated to change, you may not have really bought into the rationale behind the diet.
More on belief in a bit.
Dr. Hallberg in the U.S. and Dr. David Unwin in the U.K. have each demonstrated that a significant portion of patients under their care (as many as half) are able to reverse type 2 diabetes, going off diabetes medications, through a truly low-carb diet.
They’re just helping patients who are motivated to get healthy and lose weight, and who are willing to try a low-carb approach.
For type 2 diabetes reversal (and prevention) and for weight loss, low-carb works.
I believe low carb + periodic fasting works even better.
I can’t “prove” it by the RCT standard, and the people I’ve mentioned above may not all agree with the combination.
They each have their own emphases: Dr. Fung’s is mainly on fasting, while I think some of the others who promote low-carb think it’s most important to eat healthy fat and moderate protein meals to satiety. They say the key is avoiding hunger, which makes compliance easier.
My experience has been that combining both perspectives has led to the best result for Lisa and me.
Now back to what I said about belief.
There’s plenty of evidence that if you will adopt a low-carb eating pattern you can eat until you’re full, rarely feel hungry, improve your metabolic health and lose weight.
But as long as you toy with the idea instead of taking the plunge, you’ll never really know. As one of the great Christian theologians put it in a different context:
“Understanding is the reward of faith. Therefore, seek not to understand that you may believe, but believe that you may understand.”
St. Augustine of Hippo
Give low carb with periodic fasting a try.
Embrace the journey. Take the plunge.
If it doesn’t work for you, you can always have bariatric surgery later.
In the next few days I’ll have a post describing a new free community we’re setting up to support people in making these changes and swimming against the societal dietary currents. I look forward to telling you about it.