Fasting?

Does anyone know if fasting for maybe 24 hours or 3 days for a person with BMI of 20 or 21 would be likely to cause blood sugar to go low enough to trigger Afib? I'd really like to fast for a day, just to give the digestive system a rest, but afraid of triggering an episode.

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LaniB
Does anyone know if fasting for maybe 24 hours or 3 days for a person with BMI of 20 or 21 would be likely to cause blood sugar to go low enough to trigger Afib? I'd really like to fast for a day, just to give the digestive system a rest, but afraid of triggering an episode.

Everything is individual. I'd go and test blood sugar and perhaps ketones along the way. If it gets too low, eat. Have you ever adapted your ketone system? If you are completely new to this I'd suggest gradually lowering carb intake and your time between meals for a slow adaptation. Those enzymes are in "mothballs" if they haven't been used recently or ever. The issue with fasting is that insulin levels will drop and it will signal your body to excrete sodium. Sometimes this can get so strong, it will pull potassium with it to keep things in balance. This can cause an electrolyte disturbance that can precipitate afib. This is a description of how to avoid keto flu.

In my case, my BMI was more like 24 when I adapted in 2009. I did it by restricting carbs to 20g/day for an extended period of time. No slow onramp as I wasn't aware that would work from what I knew in 2009. Maybe 7-10 days in, I did get an episode that I converted, as usual with a loading dose of flecainide. I continued on and have remained adapted since, however my diet is much higher in carbs now (100-200 g/day) and I've remained keto adapted (I always test positive for beta hydroxybutyrate on a morning fingerstick test) since. I've subsequently done a lot of extended fasts up to 7 days, including a period around 2017 where I fasted 5 consecutive days out of every 14 days for 19 cycles (I was weight stable from day 1 of a cycle to day 1 of the next cycle). I never had another episode from fasting or ketosis. My glucose generally drops into the low 50's mg/dL (~2.9 mmol/L) on extended fasts and ketones are in the 4-8 mmol/L range. One time I did drop my glucose to 32 mg/dL (1.8 mmol/L) so went to the gym and set PR's on my lifts. When I told the story to a neurologist climbing partner friend, he said he'd only seen patients in the 30's who were comatose. I told him they obviously weren't keto adapted. My ketones were around 6 or 7 mmol/L on that day.

I've never heard of low blood sugar triggering afib. Has that happened to you?

I'm so glad you asked this and thanks for that detailed answer George. I've done "23" hour fasts... where I eat dinner and then don't eat until dinner the next night. I would like to do it more from a body rest standpoint and also religious standpoint but have been a little skittish. Never really put 2 and 2 together about insulin / sodium / potassium.

Fasting and ketosis cause people to dmp sodium. If you get to the point where you are in ketosis and feel poorly, the keto flu, you are low on salt. salt foods and coffees to taste, but you'll need up to three tsp more table salt each day.

I fasted routinely in 2020 up to 24 hrs, and didn't break the fast until soon after 20 km running and walking. No ectopic activity from my heart.

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Carey
I've never heard of low blood sugar triggering afib. Has that happened to you?

A search on the topic indicates it is mostly associated with insulin dependent diabetes, with a severe hypoglycemia. I could hypothesize that an adrenergic counter regulatory response to a hypoglycemia could be an adrenergic trigger for an afibber sensitive to them.

Thanks everyone! I'll look into getting a glucose monitor / ketone monitor before trying it. I've always wondered which foods would affect my personal blood sugar level. I don't know if low blood sugar ever caused one of my previous episodes, but a dietician once told me to keep my blood sugar level, without spikes, to stay in normal sinus rhythm. I've read that for people with a BMI of 20, fasting should be done under supervision, so made me wonder. Thanks for the tip on Potassium and Sodium!

Before my initial ablation in 2003, and early-on in my Afib journey, I learned that one potential ‘trigger’ for me was becoming hypoglycemic… either because I had gone too long between meals…or because the last meal included dessert and, with time, there was the ‘lag’ in glucose content that often set off an AF event. That motivated me to severely limit sugars and it definitely helped … until it didn’t and AF became more prevalent; thus, my ablation history
which was not just based on glucose issues. Although my doctors suspected a potential for diabetes, it didn’t ‘officially’ turn out to be the case for me… but not everyone has that result.

I still avoid regular, intentional consumption of sugar-containing foods. I tolerate fresh fruit but only with or after a meal and never alone, just as a snack, because I don’t want to ‘tempt fate.’

Note:
[www.ncbi.nlm.nih.gov]
[cardiab.biomedcentral.com]

Jackie

You can train your body to have a dual approach to metabolism. It takes some time, but your body will quickly move between autophagy and glucose metabolism once you have that routine established.

I think I would have to agree that thin people, or those whose adipose reserves are 'meager', should be careful moving into ketosis, but more-so into autophagy. If one is limiting calories to 75-85% of normal requirements so that there is weight loss, or to encourage autophagy, and one has few reserves of body fat, then the next 'food' will be muscle tissue...not usually a good choice.

I used to love extended fasting and have done it often.

Up to two weeks at a time but now I wonder if it's wise.

Lustig [youtu.be]

[www.frontiersin.org]

[www.nature.com]

[www.thelancet.com]



Edited 1 time(s). Last edit at 07/04/2023 09:06PM by PavanPharter.