Fasting can deliver metabolic tranquility

Whether I fast for a medical procedure, a blood draw, or simply to give my body a rest, it amazes me how dependably I can enter a place a peace and metabolic sanity. I am nearing the end of a 24-hour fast.


The blue dots represent my five-minute continuous glucose monitor or CGM data-points while the blue dashed line is Loop’s blood glucose forecast.


Nice! I’ve never wanted a tubed pump and I’m hoping/waiting for Loop availability to come to OmniPod, but you (and other Loopers) often brings me to reconsider my decision!

While fasting was the prime reason for this flat line, Loop gently nudged that trend forward. Whenever you start on a good closed loop system, you will feel relieved to unload some of the big D’s burden off of your shoulders.

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Awesome, Terry! That’s as good as it gets.

Awesome! Which pump are you on?

I’m using a MM722. It’s the first pump I’ve owned with a 300-unit cartridge. I only change the cartridge about every 9-11 days.

During this 24 hours fasting, what types of physical activities did you do? I am just keeping in mind that the body’s supply of glucose to fuel up it’s metabolism. We do know that when we do not eat, the body utilizes first the glucose available from muscles stored previously as glycogen. After consuming that, the body will be using the glycogen available from the liver, then after consuming all that, the body will convert fat to glucose. Is this right Terry?

To some people, this fasting experience, if the basal settings are not set right, due to not using a closed loop system, can result in hunger experience and/or hypoglycemia.

Having said all that, I do envy the success of your loop.

Flatline = beautiful. Yay!

I had a light day exercise-wise yesterday until after I broke my fast at dinner-time. I then went out for a three mile walk.

I’ve never felt any energy deficit when doing my 24-hour fasts. I have gone for extended walks while fasting (brisk but not breaking a sweat) and felt sufficient energy. I’m not sure of the order in which the body resources its energy needs but I do know that my body contains sufficient fat stores to create the glucose it needs.

Since I eat a carb-limited diet (about 60 grams/day) my body regularly needs to turn protein into glucose as well as burn some fat for energy needs. I understand that people who normally depend heavily on carbohydrates to fuel energy needs can feel this deficit more than people like me who can switch to fat-burning more easily.

I don’t feel strong hunger when I fast. In fact, I use very little will-power when I do this. I remember when I first went on a carb-limited way of eating and the hunger pangs I experienced. These symptoms are very real but typically fall away within a week or so of starting a limited carb diet.

I rarely experience hypoglycemia when I fast. If I do, it is often a very gently sloping line heading toward hypo territory that can easily be turned with 1/2 of a glucose tab. This often serves as an indication to me that my underlying basal rate needs to be reduced.


During graduate and professional school I used to fast occasionally just because I did not have the time to shop for food, prepare meals, and eat. Sometimes I would go up to four days in a row without eating anything, but that was when exhaustion would set in so I was never able to extend the fast to more than four days. I would omit my mealtime doses entirely and take around half of the background dose with fairly stable, though not perfect, control, since my blood sugar levels vary spontaneously no matter what I do.

However, I find it sad that the burden of diabetic care and the difficulties of blood sugar control have now made fasting seem like a period of tranquility, since the triumph of the discovery of insulin was understood in 1922 as abrogating the need for diabetics to fast! It is as though strict blood sugar control has finally become so brutal that we have regressed to the pre-insulin era when fasting was a frequently used mode of therapy, and hideous walking skeletons paraded around the starvation clinics of Drs. Allen and Joslin.

I don’t view fasting with the meaning that you do. I see it as an optional tactic that may be chosen to slow down glucose variability and give the person with diabetes a break from diabetes demands.

When I learned how to sail a small boat, I learned how to “heave-to.” This manuever places the two sails in opposition to each other, stalls forward progress, and permits the crew to take a rest, gather their wits, and think about what to do next. Like heaving to, I see fasting as a tactic to give me a break from the moment to moment requirements of diabetes.

The fasting I do does not exceed 24 hours; I don’t consider it a drastic technique. In fact, I only eat two meals per day, so a 24-hour fast only requires missing one meal and not snacking. I don’t see my self-imposed diabetes discipline as being brutal. I doubt that I have the fortitude to live with a harsh routine for the six years since I adopted many of my diabetes management practices.

In stark contrast to my sustainable and comfortable diabetes regimen I now employ, is the five years prior period when my blood glucose was out of control, highly variable, and mostly hyperglycemic. I felt stressed with my unsuccessful attempts to rein things in. And I felt physically miserable from the high blood glucose, brain fog, and creeping complications.

I know you likely see the style I use to manage my diabetes as overly concerned about things I will never be able to control. Luckily, I find my daily efforts reward me with good energy, a bright and consistent spirit, and the ability to pursue meaning in life beyond diabetes.


I’ve lived the 24 hr fast for the better part of 20 years. It’s a well known and followed technique aka OMAD One Meal A Day with numerous health benefits.

To read more and join in, check out Dr Jason Fungs “The Obesity Code Network: Fasting Support”

Jim, do you eat one meal a day, every day? What led you to this way of eating? Was it weight loss, diabetes control, or other benefits?

I’ll check out the Facebook group to see what I can learn.

Terry: OMAD is just personal preference. I knew nothing about the benefits. I don’t get hungry as I’ve been in ketosis for the past 4 weeks, and my body produces all the glucose it needs through gluconeogenesis (I have no glycogen stores in my body).

I started low carb about 2 months ago as I was intrigued by many of my (non-diabetic) friends on #Keto diets. Over the past 18 months I gained 20 lbs (been mostly sedentary following a diagnosis of pulmonary hypertension).

Needless to say the low carb diet rocks - no more rollercoaster blood sugars over 7.0 (125). My last HgA1C was 5.6, and that was only 4 weeks into low carb.

Keto started 4 weeks ago and I’ve lost all the weight I’ve gained in 18 months. Feel better than I have in years, and TDD is less than half what it was 3 months ago. I’ve cut all carbs out of diet - yesterday was about 5% carbs (12 grams) – all of which was totally incidental. I expect my next A1C will be somewhere in the mid 4 range :slight_smile:

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Your story is similar to mine and many others who experimented with a low or lower carb way of eating. Back in 2012 I lost 25 pounds, about 14% of my body weight, cut my total daily dose of insulin to less than half, cut blood glucose variability considerably, and drove my average blood glucose (as measured by CGM) from the 140 mg/dL (7.8) range down to less than 110 mg/dL (6.1).

Congrats on achieving such great health outcomes! It makes you wonder why this way of eating is not more widely covered and praised. Some of the main-stream medical establishment criticize low carb eating as unsustainable. I’ve been eating this way for over six years. How long does is take to show sustainability?

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I guess fasting is another term that each of us interprets differently. I, like you have a much better blood sugar day if I don’t eat. I often can go all day without eating and with basal levels set correctly, I can without any problems. I also do my walks on those days. It is so nice to see that CGM line just stay flat. This is the same thing as low carb. Everyone has a different feel for low carb.
Terry and I discussed this when he was in town and I have never really thought of myself as low carb but maybe I am. Again it’s what you think is low carb. Sure most os my meals are around 40-60carbs but I am not afraid to have a 140carb meal!
Fasting is the same thing. How long do you fast, how often do you fast etc.?

Not Terry, but this isn’t quite right Arpida. The order of glucose use is generally right (free, then stored glycogen from muscles and liver), but the body doesn’t generally convert fat (either eaten or stored) to glucose. The vast majority of fatty acid metabolism results in conversion to ATP without producing glucose or using that type of metabolism. There is a rather inefficient mechanism by which the liver can convert fatty acids to glucose (taking advantage of the gluconeogenesis pathways that normally are used in protein catabolism), which is how the brain is fueled during fasting.

So you can use fatty acids from diet or lipids stored in adipose tissue to fuel activity, and your liver can provide enough glucose to keep your brain (the only organ that actually needs glucose to function) going from stored or consumed fatty acids as well. Ketone bodies are part of the fatty acid catabolism pathway, and these are characteristic of both voluntary and involuntary fasting. Type 1s (or 2s, for that matter) in DKA are, in a sense, involuntary fasting (in the carbohydrate sense), and thus start catabolizing both muscle and fat deposits to provide energy they can’t get from the normal insulin-pathway for utilizing glucose. This makes ketones go through the roof…

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The only way I know to get good blood sugar readings is to not eat anything. I guess that’s the same thing as fasting.