Blood sugar should return to fasting levels 2 hours postprandial? 83 as normal?

I have seem several times on various medical-type sources on the Internet, all of which escape me at the moment, that even though it is allegedly ok for 2 hour posts to be up to 140, ideally, you should be back to a fasting BS of appx 83. This raises two questions:

  1. Has anyone heard, from a reliable source, that one’s sugars 2 hours PP ought to be the same, or substantially the same, as fasting?

  2. Has anyone heard, from a reliable source, that a “normal” fasting sugar is actually 83, and not below 100?

Both of these seem spurious to me, but I’ve seen them enough times that it bears asking.

– Dov

Technically, yes, it should be below 140 (for a Diabetic), but the lower, the better (as long as it’s above 70). I suppose that the 83 comes from the “average” BG at 2hr PP, for a NON-Diabetic, and what “they” consider as “normal”. The thing is, we ARE Diabetic, and what “they” consider “normal” isn’t always so easy to achieve! A Diabetic’s body doesn’t process glucose in the same way as a Non-Diabetic!

As for proof, or a reliable source. Nope, can’t say I have that, for ya!

  1. This is what I’ve been told by several endos, an internist & a CDE. Guess they are reliable sources:) Our goal should be as close as possible to what’s “normal.” Though we know there are many other factors at play, it makes sense that ideally pre & post meal readings should be pretty close. This way you know that you took the correct insulin dosage.

Went out to dinner with friends. One saw me testing after dinner & asked if she could use my meter because there are diabetics in her family & she worries about her BG. This woman, who weighs about 90 lbs, had eaten a huge carb dinner, followed by a big dessert & a sweet after-dinner cocktail. Her BG after dinner was about 100. She was worried that it was high, but it must have been the rich dessert. Didn’t get to test her again to see if her BG went down to around 80 later on. I’ve tested my non-diabetic husband & he’s in the 80’s-90’s unless he really goes overboard on carbs.

  1. Agree with Melissa–it’s an average.

My endo would like me at my target glucose of 100 at 2 hours post-prandial. 140 at 1 hour.

But you must also remember than those who take insulin are likely to still have active insulin on board for another hour or two beyond that 2 hour mark. So for insulin-takers, I might caution them not to push for so low a level at 2 hours or they may see a low at the 3 hour mark. Unless they are going low-carb and therefore took a very small bolus, of course. Then a less reactive curve seems likely and I imagine that 83 and stable at two hours is possible.

If my 2 hour BG was 83 I would be hypo soon after. For most people, fast acting insulin lasts between 3-4 hours. Some people report a shorter duration and others longer. It can also vary depending on the insulin. A lot of people say that Apidra starts acting faster and clears out of their body faster than Humalog or Novolog. I have my insulin activity set for 4 hours in my pump. It’s definitely still working past the 2 hour mark.

Dear Dov.

Such a thing may be only possible if you follow an extremely low carb and low calorie diet. I sometimes achieve it by overdosing on the bolus dose but then it would go too low without eating more. With the ADA diet it would seem impossible to me except by total luck that the kinetics of the food digestion match you insulin dose and kinetics…

In standards of care documents:
-American Diabetes Association says under 180 mg/dl 2 hours post-prandial
-The American Association of Clinical Endocrinologist says under 140mg/dl 2 hours post-prandial. AACE points out that post-prandial blood glucose spikes are linked to cardiovascular disease, a “hidden” complication for many with diabetes.

But those are broad guidelines, supposed to fit millions of people with type 1 and type 2, and to prevent fatal hypoglycemic reactions. I would guess that insulin-users who have A1Cs in the 6s tend to target under 140 2 hours post-prandial and do correction doses when they top that mark. And, as others have pointed out here, that’s a tough target if you eat more than 2-3 servings of carbs per meal.

Wow! If my BS returned to 83 2 hours after bolus and meal, I’d be in the hospital at 4 hours. My Dr. and Diabetes Educator want me to be below 160 at the 2 hour mark and back to target–100–at 4 hours, which would be time to for the next meal. From some of what I’ve read here, it seems there may be differences between Dr.'s.
So, yeah, who’s right. What exactly is the ideal? I have never been at 83 2 hours after eating! If that’s the case I’m missing the mark by a long shot, and need to do something different. What I do know is that my A1C has dropped dramatically in the last 3 months. If its not at 6.5 the next time, I may well be to far above where I need to be.

I’m actually referring to “normal” sugars; I suppose I should have specified. It was more a matter of academic curiousity, I suppose. You hear the 140 number, etc, and wonder.

Were I taking insulin and at 83 2 hours post, I’d be cramming sugar down my throat, I can assure you!

Dear Dov.

Sorry I misunderstood. I will measure my favorite female after 2 hours of christmas meal. I would expect it to be much more than 83 but I shall report.

Dear Dov.

I have just measured my wife who is not a diabetic 2 hours after diner and it was 128. I would think a target for diabetics of 140 is more than good enough. The target of 83 would be impossible except by pure luck and then it would be likely to go low.

Thanks for the info - and thank your wife for sacrificing her finger!

Believe me, I’d never try to get myself at 83 (what a strange number, anyway) with insulin - I know that’s just asking for trouble!

  1. I’ve been told that BG should be within 50 points of the preprandial number when you’re two hours post prandial.

  2. Dr. Bernstein has said that ‘normal’ is in the low 80’s. He claims to amaze pharamacy reps who visit his practice by predicting their BG, taking a fingerstick and showing them the results on a meter. Sometimes its the very meter the rep is hawking. As long as the rep is non-diabetic, he’s almost always right, because he always predicts that it will be between 80 and 85.

That’s the story, anyway.


Those are ideal numbers and definitely those that normal people get. Check out the graph and presentation linked on my page, What is a normal blood sugar?.

When we are using insulin it is possible to get those kinds of numbers or close, but it requires finding the right insulin for you and being careful about carbs. I can usually get to 100 two hours after eating when I use Apidra, which works the best for me. NOT with Humalog which gives me highs and lows no matter how I titrate it. Novolog falls in the middle as it is slower for me.

I can’t get down to 83 because I have some kind of physiological problem where I get counterregulatory bursts of liver glucose when I get below 90 almost all the time, and it probably has something to do with the odd kind of diabetes I have. But I do try to get back into the 90s two hours after meals and usually do. With Apidra I can handle 30-40 grams okay though I try to eat lower carb meals most of the time as that much carb plus insulin puts weight on me.

Solid research shows that blood sugars that leave you at 140 mg/dl at 2 hours after eating are high enough to cause neuropathy and early retinopathy, which is why you want to have blood sugars lower than that.

Lots of evidence shows people developing retinopathy and neuropathy at that 180 mg/dl at 2 hours target of the ADA. They should be ashamed of themselves for recommending it. Yes, there is “less” retinopathy and neuropathy at that level than at very high levels, but still a LOT. When we know people can avoid both complications with blood sugars under 140 mg/dl, why are they still recommending the dangerous high level?

Dear Jenny.

That is good that you liver spews out the glucose when you are below 90. I heard of a diabetic that had lost this ability after many years of type I and became brittle and had to eat tonnes of pasta to keep it from falling into life threatening lows. I am worried perhaps not reasonably that trying to control things so tightly may cause brittle diabetes.

Now I’m curious. I know that I get ~85 fasting, and I had dinner at about 6:15, so I’ll test myself in an hour and see what I come up with.