One hour blood sugar: Key to carbohydrate control and reversing diabetes

Diabetics are instructed to monitor blood glucose first thing in the morning and two hours after eating. This helps determine whether blood sugar is controlled with medications like metformin, Januvia, Byetta injections, or insulin.

But that's not how you use blood sugar to use to prevent or reverse diabetes. Two-hour blood sugars are also of no help in deciding whether you have halted glycation, or glucose modification of proteins the process that leads to cataracts, brittle cartilage and arthritis, oxidation of small LDL particles, atherosclerosis, kidney disease, etc.

So the key is to check one-hour after-eating (postprandial) blood sugars, a time when blood glucose peaks after consumption of carbohydrates. (It may peak somewhat sooner or later, depending on factors such as how much fluid was in the meal; protein, fat, and fiber content; presence of foods like vinegar that slow gastric emptying; the form of carbohydrate such as amylopectin A vs. amylopectin B, amylose, fructose, along with other factors. Once in a while, you might consider constructing your own postprandial glucose curve by doing fingersticks every 15 minutes to determine when your peak occurs.)

I reject the insane notion that after-eating blood sugars of less than 200 mg/dl are acceptable, the value accepted widely as the cutoff for health. Blood sugars this high occurring with any regularity ensure cataracts, arthritis, and all the other consequences of cumulative glycation. I therefore aim to keep one-hour after-eating glucoses 100 mg/dl or less. If you start in a pre-diabetic or diabetic range of, say, 120 mg/dl, then I advise people to not allow blood glucose to go any higher. A pre-meal blood glucose of 120 mg/dl would therefore be followed by an after-eating blood glucose of no higher than 120 mg/dl.

No doubt: This is strict. But people who do this:

--Lose weight from visceral fat
--Heighten insulin sensitivity
--Drop blood pressure
--Drop HbA1c and fasting glucose over time
--Reduce small LDL and other carbohydrate-sensitive measures

By the way, if you inadvertently trigger a high blood sugar like I did when I took my kids to the all-you-can-eat Indian buffet, go for a walk, bike, or burn the sugar off with a 30-minute or longer physical effort. Check your blood sugar again and it should be back in desirable range. But then learn from your lesson: Eliminate or reduce portion size of the culprit carbohydrate food.

Comments (27) -

  • Might-o'chonri-AL

    8/2/2011 6:11:40 AM |

    Glyco-sylation occurs inside a cell's endoplasmic reticulum lumen when certain  carbohydrates  (in the form of N-linked oligo-saccharides) meld with a newly folded protein that gets translated into  a glyco-protein.  There are different rates of activation and de-activation  between glyco-sylated and un-glycosylated proteins; this affects how that protein migrates as it tries to perform it's job and how  glycation can induce degenerative states.  Tissue cells with endoplasmic reticulum stress can exasperate certain disease progression because such "stress" there promotes more glycosylation.

  • Annabel

    8/2/2011 12:40:42 PM |

    I couldn't agree more with the advice to test every 15 minutes as a means of discovering your own "sugar curve." When I tried this, I found that my own peak falls pretty consistently at 75 minutes after beginning a meal. Testing at 2 hours completely overlooks my highest blood glucose levels.

    It's a particularly good technique for those folks whose A1c levels are higher than their fingersticks would's almost surely because they're doing their sticks way past their glucose peak.

    When test strips cost up to a buck apiece, it may feel hard to justify using six or eight of them on a single meal--but what you learn may save tens of thousands in medical bills!

  • Curt

    8/2/2011 1:31:12 PM |

    Another great article - thank you! I'm curious about your thoughts on controlled 1 hour blood sugars (mine are rarely over 110) but baseline levels that aren't much lower. Typically in the 95-105 range. I will get something in the 80s occasionally, but 100 is more common. I never really spike - even a high carb meal will only get me to 130s or so and that never really happens as I don't eat much sugar/starch at all.

    Another quick question: You've mentioned a couple times recently about this way of eating being particularly good for VISCERAL fat. That is exactly what I've found. Tremendous benefits and I feel great. I have leveled out for a while (months) in fat loss, however, with a good amount of subcutaneous fat still present. Is there another protocol for getting after this type of fat? I'm already no wheat, low carb, paleo.

    Thanks again for your excellent articles! Always learning something new.......

  • ShottleBop

    8/2/2011 1:38:20 PM |

    Do you have citations to support your statement that glycation occurs at BGs of 100 or more?  This is one of the more-commonly discussed issues on diabetes discussion boards--but folks are wont to ask for backup.

  • Jeff C

    8/2/2011 1:47:11 PM |

    Regarding glycation specifically...

    1. Do you agree that fructose ("frucation") causes more AGE than glucose?
    2. What to you make of Ray Peat's assertion that poly-fats are much more glycalating than glucose?

    "The so-called "advanced glycation end products," that have been blamed on glucose excess, are mostly derived from the peroxidation of the "essential fatty acids." The name, “glycation,” indicates the addition of sugar groups to proteins, such as occurs in diabetes and old age, but when tested in a controlled experiment, lipid peroxidation of polyunsaturated fatty acids produces the protein damage about 23 times faster than the simple sugars do." (Fu, et al., 1996)." - Ray Peat

  • Richard

    8/2/2011 3:21:55 PM |

    Thanks for the great article!
    I've just begun tracking blood sugars closely, changed my diet to one very low in carbs and no grains, and am determined to find ways to keep at it. I've started a blog just track my progress and keep me honest:
    I'll also try the 15 minute testing to see where my personal peak in blood sugar occurs.
    Again, many thanks!

  • steve

    8/2/2011 3:31:08 PM |

    Hi Dr. Davis:  What is the relationship between fasting BG taken at the Dr's office and A!C?  My fasting BG level is 73.5 but my A1C is 5.4.  I would have expected the A1C to more correspond to the fasting measurement; in the case of my wife it does.  Is it related more to the red blood cells lingering around longer or lipoprotein particles which increases the chance of glycation?  Recently had a larger than normal amount of carbs in a meal- rice and blueberries and BG spiked to 119, not to bad, but will experiment with carb portion to keep under 100 as BG may be a contributing factor to my CAD.  I am also a hyperabsorber of fat despite being an ApoE 3/3.

    As an aside, i have sent around a link of one of your interviews regarding Wheat Belly and many eyes have been opened as well as many looking to buy the book.  Might not be a bad idea to have a link to any of your interviews on Wheat Belly posted to this site.
    Thanks for the enlightening good work!

  • Dr. William Davis

    8/3/2011 12:23:09 AM |

    Hi, Shottle--
    This will be the topic of an upcoming discussion. The documentation of this effect is quite extensive. It is no longer a matter of "if" but "how much."

  • Dr. William Davis

    8/3/2011 12:25:11 AM |

    Hi, Jeff--
    This is one of oranges and apples comparisons.
    Fructose does indeed induce flagrant glycation. Glucose induces glycation, though less vigorously.

    However, there is a separate but very poorly named process called exogenous glycation which has less to do with glycation than with oxidation of fats.

    This will be the topic of future discussions.

  • Dr. William Davis

    8/3/2011 12:26:22 AM |

    My first thought is that, if weight loss is ongoing, there is a temporary situation of insulin resistance that generally dissipates with weight stabilization.

    It's also possible that your pancreas has inadequate baseline production of insulin. I'm hoping it's the first possibility.

  • Dr. William Davis

    8/3/2011 12:28:05 AM |

    Hi, Steve-

    You will find that, if you did frequent fingersticks around the clock, the highish A1c reflects the higher blood glucose values that occur after meals.

    Thanks for the feedback on the Wheat Belly project. I will indeed crosslink some of the more relevant discussions.

  • Might-o'chondri-AL

    8/3/2011 2:39:31 AM |

    Advanced glycation end products (AGE) involve some of haemoglobin's hydro-carbon Beta side chain valine residue linking up to non-polar "glucose" aldehyde compounds and certain non-"glucose" aldehydes. Various pathological kinds of AGEs can occur from distinct events; in one situation it is macrophage activity producing enzymatic myelo-peroxidase, which can activate hypochlorite favoring a serine amino acid wing to form up to make the AGE called glyco-aldehyde.

    Probably the AGE called methyl-glyoxal is the one most relevant to diabetes prevention; since Type 1 diabetics blood serum levels of methyl-glyoxal is +/- 6 times higher than normal. This AGE can be formed when the byproduct triose-phosphate (triose = subset of carbs) is generated from the glycolytic pathway called  Embden-Meyerhof; this  byproduct risks being made into methyl-glyoxal.

    Maybe the most well known AGEs are the non-enzymatic Amadori products formed via hydrolysis; one is called glyoxal coming from glucose oxidation. And the other Amadori type AGE is 3-deoxy-glucosone (3DG), which requires fructo-selysine and the fructos-amine 3 kinase cascade to shuffle together 3DG.

  • Might-o'chondri-AL

    8/3/2011 2:40:38 AM |

    Diabetes reveals the problem with AGEs; this is because diabetics risk incurring kidney nephro-pathy, One of the pathological results is oxidative kidney stress, which limits sodium (Na) excretion thereby fostering  hyper-tension . When AGEs like 3DG, glyoxal & methyl-glyoxal  (among others, like pentosidine ) circulate into the kidneys their carbonyl compounds  are hard to clear by the kidneys; the side effect is to engender  uric uremia problems and meanwhile levels of carbonyls build up in what is called "carbonyl stress".
    Japan research of the plant compound chamaemeloside found that in humans it lowered levels of the AGEs 3DG & pentosidne better than any other natural remedy; optimal response was reduction of down to 1/5 th of subject's starting levels.  Chamaemeloside is the active compound in chamomile (Anthemis noblis); the extraction formula was 1 Kg of chamomile flowers steeped covered in 20 Lt. water for 3 hours at 80* celcius ( a lab temperature probably not critical for home remedy preparation).

  • Peter Silverman

    8/3/2011 12:56:13 PM |

    Volek and Phinney in their new book about carbohydrate restriction think that as you increase  fat from 30% to 60% of your diet, insulin resistance increases, then it drops when you go above 60%.  It seems that among the most experienced researchers of carbohydrate restriction, there's little consensus about the optimal amount of fat or carbs.  Ron Krausse, for instance, thinks 35% to 45% is optimal.

  • steve

    8/3/2011 5:23:50 PM |

    When these researchers talk about carb levels are they considering vegetables to be carbs, or just fruits, grains, potatoes?

  • frank weir

    8/3/2011 6:41:32 PM |

    You must mean, "can exacerbate certain disease progression...." meaning: to increase the severity, violence, or bitterness of; aggravate

  • frank weir

    8/3/2011 6:59:22 PM |

    This is wonderful information BUT I wonder if it might be unfortunate if folks who routinely have post-prandials of 120 to 140 take your 100 level as a sign of "failure"...things are seldom so cut and dried, black and white. I don't know if I'm hitting 100 or less  after every meal, but my A1C has dropped from 7.5 to 5.8 since last November restricting carbs. And I've lost 30 pounds. I will begin to be more dogmatic about one-hour glucose checks but my rough sense is that I'm not at 100 or less a majority of the time. But I might be wrong about that. Do you see what I'm getting at? Glucose control is an ongoing process that includes lots of self education since most GP's are not keen AT ALL on restricting carbs, including mine. When I read your post, my initial feeling was, "Cripes, 100 after EVERY meal? Don't think I can do that...."

  • Might-o'chondri-AL

    8/4/2011 1:05:26 AM |

    From another commentator here, in an  earlier thread of Dr. Davis' here is how to use HbA1c to determine your average blood glucose level (note: this is not a morning "fasting" level) .
    1st: multiply your HbA1c by 28.7
    2nd: subtract 46.7 from 1st amount
    3rd: take last number as your average waking hours mg/dL blood glucose over last  few months  
    ex:  HbA1c of 5.4 x 28.7 = 159.98 minus 46.7 = 108.28 mg/dL of average blood glucose level

  • Peter Silverman

    8/4/2011 2:24:31 AM |

    They don't count non-starchy vegetable as carbs.

  • ShottleBop

    8/4/2011 3:15:11 AM |

    Thanks for the heads up!

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  • Stephanie

    8/4/2011 2:13:27 PM |

    Dr. Davis,
    I have found that if I take my carb level too low (below 50g per day) that my fasting blood glucose levels actually go up rather than down.  If my carb intake is closer to 70-80, my fasting glucose is lower.

    Have you had this experience with some of your patients?  Can you shed any light onto what might be happening?


  • Anne

    8/4/2011 2:34:11 PM |

    Non-starchy vegetables do have carbs and I do have to count them. A half cup of broccoli can have about 6 carbs and since I limit my carbs to no more than 15g/meal, that broccoli on my plate is significant.

    I found getting a scale that reads carbs too was an important tool for me. I found I was ofter overestimating how much of a low carb veggie I could eat. If my blood sugar starts to rise, I go back to measuring and that seems to get me back on track.


  • majkinetor

    8/14/2011 1:25:56 PM |

    I think thats normal, its commonly encountered on paleo forums/blogs. It has something to do with physiological insulin resistance, Petro @ Hyperlipid talked about. Look here:

  • majkinetor

    8/14/2011 1:38:24 PM |

    I wouldn't suggest that everybody blindly follow CHO < 50g / day. As always, its about the context. People usually forget that. We mostly extrapolate from results of people who already have metabolic problems.

    Anyway, I am currently perfectly healthy apart from some minor dermatology problems (eczema).
    When I have prolonged periods of reduced CHO input (around 50g / day), I eventually start having some mucus problems. Dry eyes particularly, but also joint pain. I am not 100% sure if its about low carb diet, but it looks like it. Now I target 75g < CHO < 100g per day by adding small potato and a bit more chocolate to my diet.

    I think overemphasizing carb reduction is not good thing for most people. Carbs should go down by pretty big amount for most people, but not to extreme. In anyway, its better to measure then to guess. My sugar is never above 110 after meal and fasting is always around 95.

  • John F

    8/13/2012 9:48:10 AM |

    I decided to take this advice and have been tracking my 60 mins postprandial blood glucose for the past two days to see if all the years I've been low carbing have been making any difference. Especially working my way through different foods to see how they affect me and I've ranged from 64 mg/dl to 97 mg/dl so I'm pretty hapy.

    However this evening 60 minutes after my dinner of panfried steak with a creamy cajun sauce I got a reading of just 55 mg/dl. A lot of websites say this is too low. I'm 32, healthy male, 5,9", weigh 160 lbs, not diabetic and I don't feel sick so I'm not sure what to make of this low reading. The only thing I did was finish a hard CrossFit workout about 30 mins before I had dinner... so a total of 90 minutes before the blood glucose test.

    Any advice on what this "low" reading means? I'm hoping it's normal and means I'm burning fat!