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Why Does Eating Lower My Blood Glucose Instead Of Raising It?

A DiabetesTeam Member asked a question 💭
Annapolis, MD

How can I have a bg reading of 182 and then immediately eat a meal and get a reading of 88 two hours later? The first reading was fbg; the meal was breakfast. This just defies the whole premise that food elevates blood glucose-instead of lowering it. Especially when the meal was hot oat bran cereal with half a banana and walnuts. (more than half of my daily carb allowance in one meal) I think I'll just go 'eat worms'!

November 17, 2022
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A DiabetesTeam Member

@A DiabetesTeam Member to get that answer you need to know a little about what our body is doing before and after we eat

So anytime we haven't eaten for between 4 and 6 hours it goes into "fasting mode". To differentiate between fasting while sleeping and between meals while awake, a BG that is taken after sleeping is called a Fasting Blood Sugar and between meals is call a Pre-Prandial Blood Sugar.

When we are fasting our body still needs "lots of sugar" to function. So the Liver stores and releases sugar to provide that function. Hormones turn the sugar release off or on as required.

While sleeping a hormone tells the liver to dispense enough sugar to keep things running. Then, when we start to wake up a couple different hormones ask for "a whole lot extra" - it takes significant energy (sugar) to get from unconscious to conscious.

Our problem as Type 2's is our system is a little broken. So when the Liver throws that Sugar Party we "may have" all kinds of leftovers and our Blood Sugar runs high.

The Liver will keep putting out sugar until the end of time until it senses a couple of "different" hormones that are ONLY released when we eat something (or take a diabetes med that "fakes them").

When food hits the stomach a hormone called GIP is released. Then when it passes from the stomach a second hormone, GLP-1 is released.

Those two hormones do two things.

First they "turn off the liver" so it stops pumping sugar into our blood (so it won't rise due to liver sugar)

Second, it tells the pancreas to release insulin which then converts our blood sugar to energy OR body fat.

Even though you "ate something" ultimately adding even a bit more sugar into your blood, the insulin release deals with that AND the high fasting sugar - it doesn't care where the sugar came from - and if your insulin production part is working properly then your blood sugar returns to a "more normal level".

(most of us produce more than enough insulin, just don't use it well - but the pancreas "tries" to deal with all the blood sugar, but only when it's "turned on" which is primarily triggered when we eat something and it keeps the insulin "turned on" until digestion is finished (up to 3'is hours after eating) and then another hormone turns it off (or we would go and die).

There is only two states - Liver putting sugar out and insulin off or Insulin going out and Liver sugar shut off.

(actually, a little more complicated because the pancreas always "leaks out" a little insulin 24 hours a day, but insufficient amount to deal with someone that has insulin resistance, so WE need to eat to get the insulin production cranked up)

November 17, 2022
A DiabetesTeam Member

@A DiabetesTeam Member yes, it is super important for "everyone" to eat breakfast within the first hour of waking up. Helps reset our metabolism (body clock).

For Diabetics it stops the fasting sugars and induces an insulin release similar to taking a shot of mealtime insulin (bolus insulin users) - so get the effect of a "shot" without having to stick ourselves.

And yes, elevated fasting numbers can be "mostly" about the liver. And that is why metformin is always the first drug prescribed.

Metformin "restricts" the amount of sugar the liver can release. It does "nothing else" - zilch for meal time sugars.

All of the other Diabetes meds are designed to deal with mealtime sugars from the food we eat and may have little or no effect on sugars from the liver.

That's why the only alternative to Metformin is Long Acting (Basil) Insulin - to deal with Liver sugar you either have to slow it down or use insulin to deal with it.

Fixing or fine tuning your metabolism will, over time, have a positive effect on fasting sugars. Losing weight will also burn up some of the fat in/around the liver and it will regulate better. Plus as our body weight gets closer to normal, our insulin resistance improves.

So weight loss is greatly under valued and under recognized as a "treatment" for diabetes. Aiming for normal weight could result in less sugar produced/released and better use of insulin - both resulting in lower blood sugar "all the time".

November 17, 2022
A DiabetesTeam Member

Good morning @A DiabetesTeam Member,
I eat when I first get up to break my overnight fast. Breakfast.

In preparation for the activity of waking up, hormones are released to get the liver to dump stored glucose (glucogen). This raises your blood glucose. The taps for this glucogen keep dumping into your system, till you shut them down by eating a serving of carbs. A normal serving is 15 carbs.

15 carbs =
1 slice bread
1/3 cup pasta
1/3 cup rice
1/3 cup potatoes
1/3 twinkie
A little less than 1/3 cup cake.

For me my magic number is 5-8 carbs.

For you, you need to eat to shut off the glucogen tap. You apparently aren’t very insulin resistant, as your 2 hour number shows. You also seem to produce a fair amount of insulin when called for too.

Good luck

November 17, 2022
A DiabetesTeam Member

Thanks for the validation, @A DiabetesTeam Member The fickleness of fbg is enough to make me want to bang my head on the keyboard some mornings. In my case, I have been fortunate enough to be able to watch my weight drop 1-2 lbs a week, which is rewarding. The same with my BP- my physician lowered my BP meds by half strength just yesterday. But the blood glucose seems unchanged (and possibly worse even). Hard to tell, even with the finger pricks, because of the annoying elevated fbg. My doc also agreed to stop the diuretic altogether, since it had me getting up several times a night to pee (which could mess with my fbg). I suspect at best case I need to 'fix' my fatty liver and unhealthy metabolism before I am able to see any significant changes to my blood glucose. I am researching about some supplements to help my liver in the meantime. Anyways, I read somewhere that losing just a small percentage of weight (maybe 5-7%?) can lower blood glucose-that hasn't happened for me. But I am in it for the long haul. You will hear about it if I succeed!

November 18, 2022
A DiabetesTeam Member

You do not inform us what medication you took prior to having breakfast. If you took an insulin injection between your test and your meal, then it stands to reason that the medication did what it was supposed to do. It regulated your blood sugar level.

November 17, 2022

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