Fasting, Dawn Phenomenon, Insulin and BP?

health
(Eric - The patient needs to be patient!) #1

Starting my only 2nd EF yesterday. Feeling great but only 18+ hrs in.

Took my BG this morning at ~18 hrs in. 130mg/dl which is typical for me. (A1c 5.4) I clearly have the dawn phenomenon. BP was up +5/+12 points as well from the last couple of days. My BG most morning and with dr drawn blood is 120 to 130.

I have an overactive sympathetic nervous system, hence put on BP meds at ~25yo. I’m now 65yo. My resting heart rate used to be 100+.

I’m way calmer now than when I was younger and I have started a daily mindfulness meditation practice as well. My resting BP is better on average than it has been in many years due to keto and weight loss, but I’m still on 3 meds. My resting heart rate is 55 to 65 ppm.

So I’m wondering, does the dawn BG levels reduce the effectiveness of the fast because I would assume that I get a spike of insulin from the dawn rise? Will fasting reduce my dawn BG levels over time? Is this a chicken and an egg situation? Fast to make it better but fasting may be hampered some from the dawn effect?

I’d love to hear from others about your dawn BG experience and fasting.

I think I will measure my BG this evening after 30+ hrs of fasting.

(Bob M) #2

Even if the dawn BG reduces the effectiveness of the fast, there is nothing you can do about it. What I find happens is that my BG goes up from a lower around midnight or so until close to noon, then goes down all day until midnight. Eating creates “waves” on top of this, but that’s what happens. If I fast multiple days, the line comes down, meaning that my overall BG numbers go down, including those in the morning. See this data, which is a month’s worth of data from a CGM:

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(Bob M) #3

Oh, to get US data, multiply by 18, so 5.3=95.4. Note this is also likely low, as I tend to be around 100 in the mornings. But this shows you the pattern, and I have months of data just like this.

What should happen is that the more you fast, the more your BG in the morning should lower. Unfortunately, I’ve not figured out whether that is true in my case or not, and I’ve run out of sensors, and they’re too expensive (about $65/month) for me to keep buying.

(Eric - The patient needs to be patient!) #4

Bob,

Thanks for the info and analysis.

(Bob M) #5

If you want to reduce your morning blood sugar, there are steps you can take. For instance, taking 1 or 2 tablespoons of apple cider vinegar before bed has been shown to reduce morning blood sugar level. There may be other vitamins (alpha-lipoic acid?) that might help too.

Personally, I get confused about morning blood sugar level. As a marker for people on high carb diets, it just tells you you’re likely insulin resistant. You’ll also see studies where people with certain blood glucose levels have higher or lower risks of disease, especially for “fasting” blood glucose. I can tell you that my “fasting” blood glucose follows that line above, higher in the morning, lower at night. Which glucose is my “fasting” glucose?

That’s the problem with markers, especially ones that change all day long.

I pretty much have resigned myself to what I get is what I get. I try to fast, eat low carb, have very few high carb incidents, eat low PUFA, etc. That’s the best I can do. If my blood sugar is still above 100 in the morning, so be it.

I also wonder if as very low carb people, our blood sugar SHOULD be higher in the morning. After all, I’ve been low carb/keto for 5+ years. If my blood sugar was going to drop, I think it would’ve dropped. Maybe if I keep fasting and eating low carb, at some point, my blood sugar will be below 100 in the morning. We’ll see. But if not, there’s not a lot I can do about it, and no studies that have followed low carb people for 5+ years specifically looking at this marker, so I don’t know if it’s bad or not.