Timing of blood sugars

3. March 2010 William Davis (5)
Because different foods generate different blood sugar (glucose) responses, the timing of your blood sugar is an important factor to consider.

This question has come up a number of times. Commenters have asked whether the one-hour postprandial glucose is timed with the start of the meal or the conclusion of the meal.

In my view, if we simply ignored all aspects of meal composition, then blood glucose should be obtained one hour after the conclusion of a meal. This is because most mixed meals (i.e., mixed in composition among proteins, fats, and carbohydrates) yield peak blood glucose levels at 60-90 minutes after consumption. Timing blood glucose to 60 minutes after the conclusion of a meal puts the sample right about at the peak.

But this is an oversimplification. For instance, here is the blood glucose behavior after so-called "complex" carbohydrates wheat bread, rye bread, rye made with beta glucan, and whole wheat pasta (50 grams carbohydrates each) in slender, healthy volunteers, mean age 29 years:


From Juntunen et al 2002

Note that blood glucose peaks at 35 minutes postprandial. (To convert glucose in mmol/L to mg/dl, multiple by 18. Thus, whole wheat bread increased blood glucose from 94 mg/dl to 122 mg/dl. Also note the lower peak glucose for pasta, but sustained higher glucose levels hours later.)

In another study, older (mean age 64 years), overweight (BMI 27.9) females with diabetes were given 50 grams carbohydrate, 50 grams carbohydrate with olive oil, or 50 grams carbohydrate with butter:


From Thomsen et al 2003. Control meal of soup plus 50 g carbohydrates ({blacktriangledown}), the control meal plus 80 g olive oil ({circ}), and the control meal plus 100 g butter (•).

In this experience, note that postprandial glucose peaks 60-120 minutes after the meals (consumed within 10 minutes), delayed more when either oil is included. Blood glucose started at 144 mg/dl and peaked as high as 230 mg/dl with carbohydrates only; peaks were reduced (along with AUC) when oil was included. (Note the differential effect, olive oil vs. butter.)

These two sets of observations give you a range of blood glucose behavior. One side lesson: Carbohydrates should never consumed by themselves, else you will pay with a high blood sugar (not to mention the hypoglycemic response later for many).
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Comments (5) -

  • steve

    3/3/2010 5:14:02 PM |

    does this include eating celery or cucumbers as a snack, or other veggies?

  • Hollie

    3/3/2010 6:12:24 PM |

    I began checking my blood sugar after reading about it here a few weeks ago, and was surprised to find that my blood sugar peaked a full two hours after a meal. At first I'd been doing the 1-hour, which this site suggests, but then I read fully the directions that came with my reader, and it said to check 2 hours after a meal.

    Of course, these directions are aimed at diabetics, and I'm assuming this site is aimed at folks who are either normal or perhaps pre-diabetic. I was a little disturbed to find that my insulin response appears to react in a diabetic way, although my actual blood sugars are still in the pre-diabetic range. Either way, I'm watching this a lot more carefully now, and this whole experience is the first thing in years that has really inspired me to work at getting off my lifelong sugar addiction. Thanks Doc!

  • Anonymous

    3/3/2010 9:46:00 PM |

    Dr. Davis,

    In cases where lean meat is included with vegetables and some fat, would this lead to an even more gradual rise in blood glucose?

    For several years now I have been in the habit of never consuming carbohydrates alone and always make sure to include either 20-30g protein + vegetables or 20-30g protein + vegetables + fat with any carbohydrates ingested.

    Bill Virdon

  • Adolfo David

    3/4/2010 2:40:46 AM |

    In your last LEF Magazine article about Frailty was a little strange to me not find Q10 when you talk about energy boosters. I usually recommend Q10 Ubiquinol for this purpose to old people. Anyway, thanks for your work, I hope one day I can read next parts of "Understanding Risk Factors for Heart Disease" you started in August 2009 in this great magazine.

  • Anonymous

    3/28/2010 6:33:35 PM |

    You'll have to determine when your own peaks occur after meals, but ours are consistently within the range of 30 to 60 minutes, depending on the meal. Of course, if the meal includes a dessert, etc., then you'll get multiple peaks. And if the meal is prolonged, such as a holiday meal, then all bets are off. But for those consuming lots of small meals during the day (to keep peaks low), 60 minutes is almost certainly too long to wait.

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Beating the Heart Association diet is child's play

Beating the Heart Association diet is child's play

21. June 2009 William Davis (19)


In response to the Heart Scan Blog post, Post-Traumatic Grain Disorder, Anne commented:


While on the American Heart Association diet my lipids peaked in 2003. I even tried the Ornish diet for a short time, but found it impossible.

Total Cholesterol: 201
Triglycerides: 263
HDL: 62
LDL: 86

After I stopped eating gluten (I am very sensitive), my lipid panel improved slightly. This past year I started eating to keep my blood sugar under control by eliminating sugars and other grains. Now this is my most recent lab:

Total Cholesterol: 162
Triglycerides: 80
HDL: 71
LDL: 75


Isn't that great? This is precisely what I see in practice: Elimination of wheat and sugars yields dramatic effects on basic lipids, especially reductions in triglycerides of up to several hundred milligrams, increased HDL, reduced LDL.

Beneath the surface, the effects are even more dramatic: reductions or elimination of small LDL particles, reduction or elimination of triglyceride-containing lipoproteins, elimination of the marker for abnormal post-prandial (after-eating) lipoproteins, IDL, reduced c-reactive protein. Add weight loss from abdominal fat stores and reduced blood pressure.

In fact, I would go so far as to speculate that, if the entire nation were to follow Anne's lead and eliminate wheat and sugars, "need" for 30% of all prescription medications would disappear. The incidence of diabetes would be slashed, the U.S. would no longer lead the world in obesity.

Anne and I are not the first to make this observation. It has also been made in several studies, such as:

The Duke University study of low-carbohydrate diets in type II diabetics. In this study, 50% of low-carb participants became non-diabetic: They were cured.

One of the many studies conducted by University of Connecticut's Dr. Jeff Volek, demonstrating dramatic improvement in glucose, insulin (reduced 50%) and insulin responses, and lipids.

Dr. Ron Krauss' early studies that hinted at this effect, even though the "high-fat" diet wasn't really low-carbohydrate.

If wheat and sugar elimination has been shown to achieve all these fabulous benefits, why hasn't the American Heart Association spoken in favor of this dietary approach and other- low-carbohydrate diets ? Why does the American Heart Association maintain its "Check-Mark" stamp of approval on Cocoa Puffs and Count Chocula cereals?
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Comments (19) -

  • Peter

    6/21/2009 3:17:36 PM |

    I stopped eating wheat and sugar after I read Gary Taubes's book (Good Calories, Bad Calories).  I haven't lost any weight, but I suspect it's still a good thing: it's not like there's a shortage of things to choose from.  But it's hard to imagine that my body was designed for refined food products.

  • Mark K. Sprengel

    6/21/2009 4:34:22 PM |

    I'm trying to explain low carb to my fiance and could use some help. I tried the Atkins diet a few years back, lost nearly 30 lbs and dropped my slightly over 200 cholesterol to 150 IIRC. I was working out a lot as well.

    The problem is that she and her dad tried Atkins and the father ended up in the hospital and she got sick. The Dr. said that since Atkins/lo carb became popular they had more problems with colon issues.

    They apparently were getting enough fiber and water. I'm thinking potassium might be an issue for her as at some point in her life they said she was low and needed to eat more potassium rich foods.

  • DrStrange

    6/21/2009 5:22:26 PM |

    In the Voleck study, low carb was 12% carbs but what was called low fat was 24% fat.  My experience and research by McDougall, Ornish, Esseltyn, etc indicates that if a truly low fat diet (10% fat; the difference made up by adding more complex carbs) were tested the results would be at least as good as if not superior to the low carb diet.

  • Ross

    6/21/2009 5:30:16 PM |

    In answer to your last question: Because the American Heart Association derives a significant fraction of it's funding from Cargill, ADM, General Mills, and other agribusiness giants.  If the AHA changed to a set of dietary recommendations that didn't help line the pockets of agribusiness by creating demand for highly processed foods (whole foods are notoriously unprofitable), it would mean the end of their funding stream.

    Follow the money and most mysteries are solved...

  • AKLAP

    6/22/2009 12:01:06 AM |

    Keep up the great work Anne & Dr. Davis!

  • ShawneeL

    6/22/2009 4:14:09 AM |

    Hi, see some of my posts at www.dailyrantingspot.blogspot.com where I talk about some of the boring science of low carb.  Anne's experiences are common for people who eliminate carbs from their diet.

  • ShawneeL

    6/22/2009 3:40:51 PM |

    This is why South Beach is a bit better, because of the emphasis on vegetables with fiber, and drinking enough.  I know my husband's triglycerides have plummeted to low normal.  A low fat diet doesn't "satiate" you enough that you can stand not to eat.  Obese people get used to eating, and that's a problem for attempting to lose weight.

  • Anonymous

    6/22/2009 6:23:42 PM |

    I don't know if ornish, etc. is truly superior.  I think that superior would have to be sustainable.  For all but probably 5% (pure guess here) of the population, that type of very low fat, vegan, diet is not sustainable or maintainable.

    I think that wheat free, no sugar, low carb, real foods diet is much more sustainable/maintainable for a great percentage of the population.  And, a lot of Esselstyn's work was with low dose Chol. meds.  Dr. Davis appears to take the no-meds approach.

    As an experiement of 1, my labs on a very near Esselstyn diet were further from the 60/60/60 goal of Dr. Davis than they were on a very near TYP diet that included quite a few more carbs than likely recommended.

  • billye

    6/23/2009 3:37:05 PM |

    Drstrange, for 50 years I tried to eat the so called healthy diet.  My favorites were McDougal and Ornish among 25 other low fat high carb gurus.  I gained after yo-yowing, 60 pounds and along the way I developed diabetes type 2 and kidney disease.  Thanks to Dr. Davis and my kidney doctor who is an advocate for low carb diets and turned me on to this blog and now writes his own www.nephropal.blogspot.com, I have been eating low carb for 7 months now and I am down 50 pounds and now have an hbA1c of 4.7.  While I know that kidney disease can't be cured, some of my kidney disease numbers have improved.  Forget about high carb and low fat, that's what is killing us.

  • TedHutchinson

    6/23/2009 6:57:01 PM |

    We now see more and more products jumping onto Omega 3 health benefits to market fundamentally unhealthy foods.

    Kellogg’s Live Bright Brain Bars contain 100 mg of DHA which is one-third of the 300 mg of DHA/ EPA recommended by the American Heart Association.

    But if you look at the ingredients of these bars you find.
    Coating Sugar, Partially Hydrogenated Palm Kernel Oil, Cocoa Processed with Alkali, Whey, Nonfat Milk, Soy Lecithin, Sorbitan Monostearate, Salt, Artificial Flavor, Polysorbate 60 , High Fructose Corn Syrup , Whey Protein Isolate , Soy Protein Isolate , Maltodextrin , Semisweet Chocolate Sugar, Chocolate, Cocoa Butter , Corn Syrup , Sugar , Palm Oil with TBHQ for Freshness , Cellulose , Sunflower Oil , Cocoa , Glycerin , Algal Oil Natural Source of DHA , Natural and Artificial Flavor , Salt , Sodium Ascorbate Vitamin C , Vitamin E Acetate , Soy Lecithin , Mono- and Diglycerides , Citric Acid , Folic Acid , Bleached Wheat Flour , Partially Defatted Peanut Flour , Mixed Tocopherols for Freshness , Pyridoxine Hydrochloride Vitamin B6 , Ascorbic Acid for Freshness , Vitamin B12

    It really is outrageous that products like this are promoted as Brain Health Bars. While I am certain that no one reading this blog will be under any illusions that consuming Omega 3 rich crap is anything other than crap, I am concerned that there are people who will think that these foods are making a meaningful contribution to the omega 3 intake and will not be aware that omega 3<>omega 6 ratio will still be distorted or that omega 6 intake has to reduce to around 4% of calories before the adverse effects of omega 6 are negated.

  • DrStrange

    6/23/2009 8:07:04 PM |

    I think it is totally dependent on individual physiology.  I believe, w/ nothing to back me up, that there is a bell shaped curve and that most people (the big part of the bell), can do well on either low carb/high fat or low fat/high carb.  The tails of the bell are the few who can only do well on one or the other.  I do great on low fat!  My numbers are excellent and I feel good. On low carb I am always tired, irritable, brain fogged and feel like I am starving. My wife is the opposite.  If she eats more than a few grams of carbs per day she blows up w/ phlegm and fatigue and digestive problems.  Not just gluten grains but any carbs at all except veg.  She also must minimize fruit or pay the price.  So we are Jack Sprat and Spouse.

    I have seen this in several people.  There are a few out there who just do not process fats well and some who do not process carbs well.  And I also know people who have done both and felt great on both.  The key is that "combining the two" ie high carb/high fat is what really will kill everyone!

    So far as I know, the only way to know is to experiment on yourself as you have done and listen to your body because it never lies.  When you find one that works for you then you are home.

  • Manu

    6/24/2009 2:57:04 AM |

    Is sprouted wheat bread also to be avoided?

  • Anonymous

    6/25/2009 3:30:24 AM |

    Hi Dr. Davis,

    I wanted to let you know there is an excellent discussion on weight gain, located at
    http://www.dhslides.org/mgr/mgr060509f/f.htm

    It is a lecture at a Hospital by Gary Taubes, the author of "Good Calories, Bad Calories"

    I read the book, and really enjoyed watching this hour-long lecture.

  • Sifter

    6/26/2009 3:10:49 PM |

    Dr. Davis, have you seen this, posted June 25th 2009...

    "High Carbohydrate Foods Can Cause Heart Attacks!

    In a landmark study, new research from Tel Aviv University now shows exactly how these high carb foods increase the risk for heart problems.
    Enormous peaks indicating arterial stress were found in the high glycemic index groups: the cornflakes and sugar group. "We knew high glycemic foods were bad for the heart. Now we have a mechanism that shows how," says Dr. Shechter. "Foods like cornflakes, white bread, french fries, and sweetened soda all put undue stress on our arteries. We've explained for the first time how high glycemic carbs can affect the progression of heart disease." During the consumption of foods high in sugar, there appears to be a temporary and sudden dysfunction in the endothelial walls of the arteries.
    Endothelial health can be traced back to almost every disorder and disease in the body. It is "the riskiest of the risk factors," says Dr. Shechter, who practices at the Chaim Sheba Medical Center — Tel Hashomer Hospital. There he offers a treatment that can show patients — in real time — if they have a high risk for heart attacks. "Medical tourists" from America regularly visit to take the heart test.
    The take-away message? Dr. Shechter says to stick to foods like oatmeal, fruits and vegetables, legumes and nuts, which have a low glycemic index. Exercising every day for at least 30 minutes, he adds, is an extra heart-smart action to take."
    ....from conditioningresearch.com

  • Sifter

    6/26/2009 3:11:39 PM |

    From ConditioningResearch.com 6/25/09

    In a landmark study, new research from Tel Aviv University now shows exactly how these high carb foods increase the risk for heart problems.
    Enormous peaks indicating arterial stress were found in the high glycemic index groups: the cornflakes and sugar group. "We knew high glycemic foods were bad for the heart. Now we have a mechanism that shows how," says Dr. Shechter. "Foods like cornflakes, white bread, french fries, and sweetened soda all put undue stress on our arteries. We've explained for the first time how high glycemic carbs can affect the progression of heart disease." During the consumption of foods high in sugar, there appears to be a temporary and sudden dysfunction in the endothelial walls of the arteries.
    Endothelial health can be traced back to almost every disorder and disease in the body. It is "the riskiest of the risk factors," says Dr. Shechter, who practices at the Chaim Sheba Medical Center — Tel Hashomer Hospital. There he offers a treatment that can show patients — in real time — if they have a high risk for heart attacks. "Medical tourists" from America regularly visit to take the heart test.
    The take-away message? Dr. Shechter says to stick to foods like oatmeal, fruits and vegetables, legumes and nuts, which have a low glycemic index. Exercising every day for at least 30 minutes, he adds, is an extra heart-smart action to take.

  • Fat Bastard

    7/4/2009 5:32:19 AM |

    Eat what ever you want. I have had 3 heart attacks. Life is short and it mostly sucks so be a glutton like me.

  • Trinkwasser

    7/14/2009 3:43:42 PM |

    I'm insanely jealous of that LDL!

    Statins knocked mine down but diet doubled my HDL and decimated my trigs (not a Heart Healthy diet, obviously, but a truly heart healthy diet of low carbs and masses of fat protein and veggies)

    Sadly my latest experiment failed - dropping the statin whacked my TChol back up, and the *receptionist* cancelled my A1c and Full Lipid Panel so I have had to see the doctor to authorise the correct tests, results in about a week. I suspect HDL will have further improved but LDL is the major culprit so I may end up restatinating myself.

    Another excellent paper from Jeff Volek looking at some more obscure cardiovascular markers

    http://www.nutritionandmetabolism.com/content/3/1/19

  • P90X

    4/9/2011 12:12:11 PM |

    It is "the riskiest of the risk factors," says Dr. Shechter, who practices at the Chaim Sheba Medical Center — Tel Hashomer Hospital. There he offers a treatment that can show patients — in real time — if they have a high risk for heart attacks. "Medical tourists" from America regularly visit to take the heart test.

  • Sten Ekberg D.C.

    5/12/2011 10:23:10 PM |

    A patient of mine recently alerted me to Dr. Davis's blog and I am delighted to read some of the entries. It is fantastic that some members of the medical community have the guts to think for themselves and tell it like it is. I've told my patients for years that the recommendations of the American Heart Association will give you a heart attack and the American diabetes association will give you diabetes. If you actually read the textbooks in medical school, it is plain to see that carbohydrades  trigger insulin which is a fat-storing hormone. After 30 years of low fat propaganda it is uplifting to see that some common sense is making the news. Whole foods is the only food your body knows what to do with. Keep it up. Dr. Davis.

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