Construct your glucose curve

In a previous Heart Scan Blog post, I discussed how to make use of postprandial (after-meal) blood sugars to reduce triglycerides, reduce small LDL, increase HDL, reduce blood pressure and inflammatory measures, and accelerate weight loss.

In that post, I suggested checking blood glucose one hour after finishing a meal. However, this is a bit of an oversimplification. Let me explain.

A number of factors influence the magnitude of blood glucose rise after a meal:

--Quantity of carbohydrates
--Digestibility of carbohydrates--The amylopectin A of wheat, for example, is among the most digestible of all, increasing blood sugar higher and faster.
--Fat and protein, both of which blunt the glucose rise (though only modestly).
--Inclusion of foods that slow gastric emptying, such as vinegar and fibers.
--Body weight, age, recent exercise

Just to name a few. Even if 10 people are fed identical meals, each person will have a somewhat different blood glucose pattern.

So it can be helpful to not just assume that 60 minutes will be your peak, but to establish your individual peak. It will vary from meal-to-meal, day-to-day, but you can get a pretty good sense of blood glucose behavior by constructing your own postprandial glucose curve.

Say I have a breakfast of oatmeal: slow-cooked, stoneground oatmeal with skim milk, a few walnuts, blueberries. Blood glucose prior: 95 mg/dl. Blood glucose one-hour postprandial: 160 mg/dl.

Rather than taking a one-hour blood glucose, let's instead take it every 15 minutes after you finish eating your oatmeal:

In this instance, the glucose peak occurred at 90-minutes after eating. 90-minute postprandial checks may therefore better reflect postprandial glucose peaks for this theoretical individual.

I previously picked 60-minutes postprandial to approximate the peak. You have the option of going a step better by, at least one time, performing your own every-15-minute glucose check to establish your own curve.

Comments (24) -

  • Eric

    2/19/2011 5:03:57 AM |

    Have you ever used a DexCom 7, like Tim Ferriss did for the 4 Hour Body book?

  • Kurt

    2/19/2011 12:55:16 PM |

    There is evidence that alcohol decreases the blood glucose rise, which may explain in part why moderate drinkers have lower risk of heart attacks. Have you found this to be true?

  • Anonymous

    2/19/2011 3:01:47 PM |

    With all respects, Doctor Davis, but I am at a loss to understand your reasoning behind the suggestion of constructing a 2-hour curve with readings taken every 15 minutes. Invariably after eating, blood glucose level will rise and then fall over the two-hour period. I can control the severity of the "spike" by the type of food I consume. After eating however, I cannot control the shape of the curve without the intervention of medication or physical exercise. This is known. So what additional practical information is provided me from this exercise?
    My regards, StanO

  • Anonymous

    2/19/2011 3:09:36 PM |

    Hi! These are my readings using a 1-low carb meal-day approach during months.

    day   hour mg/dL
    02/15 11:17 74
    02/15 12:57 83
    02/15 13:53 79
    exercise lifting weights
    02/15 15:11 93
    end of exercise
    02/15 15:46 75
    02/15 16:22 86
    02/15 16:49 83
    meal time

    As you can see these are my pre-meal levels in a low carb diet, one meal a day approach eating nuts, yogurt, liver, meat, fish, especial atkins bread, butter, chicken, eggs etc..

    Next day I change my normal low carb meal for a high carb meal (pasta with a bit of meat) with my morning sugar in these same levels. Lets the party begin.

    02/16 13:20 finish pasta festival
    02/16 13:29 114
    02/16 13:42 103
    02/16 13:57 125
    02/16 14:06 127
    02/16 14:12 137
    02/16 14:23 119
    02/16 14:36 126
    02/16 14:48 130
    02/16 15:03 123
    02/16 15:15 106
    02/16 15:30 112
    02/16 15:46 111
    02/16 16:11 107
    02/16 16:22 105
    02/16 16:47 114
    02/16 17:21 121
    02/16 17:32 120
    02/16 18:07 113
    02/16 18:21 125
    02/16 18:50 110
    02/16 19:42 114
    02/16 20:21 130
    02/16 21:29 112
    02/16 23:37 119
    time to bed. I also feel like shit.

    Next day, do you think the party is over?

    02/17 07:20 121 (no)
    02/17 12:15  71 (finally, nearly 24 hours of high sugar levels!)
    02/17 13:00  84
    02/17 14:50  81
    02/17 15:57  71
    02/17 16:30  end meal (with a bit of wheat bread)
    02/17 16:48  99
    02/17 17:08 111
    02/17 17:27  94
    02/17 17:47  82
    02/17 18:18  87
    02/17 18:42  73
    02/17 20:09  78
    exercise (please, do not ask what type of exercise and how I can manage to check my sugar in that situationSmile
    02/17 21:31  98
    02/17 22:01  97
    end of exercise
    02/17 23:15  88
    02/17 00:38  83

    Next day

    02/18 09:18 79
    02/18 10:36 81
    02/18 11:38 85
    exercise (ski, more aerobic so my sugar levels do not increase to much. Cannot use the sticks due to low temp)
    02/18 18:00 80
    low carb meal using  whole grain special atkins bread
    02/18 18:31 85
    02/18 18:47 98
    02/18 19:08 90
    02/18 19:30 88
    02/18 19:45 93
    02/18 20:20 87
    02/18 20:40 80
    02/18 21:12 92
    02/18 21:58 94
    02/18 22:26 91
    end of exercise
    02/18 23:39 88
    02/18 01:17 88
    02/18 02:20 93
    end of exercise

    Next day similar to my first set of data.

  • Geoffrey Levens

    2/19/2011 5:01:08 PM |

    "I am at a loss to understand your reasoning behind the suggestion of constructing a 2-hour curve"

    Varies so much per person and meal composition.  Some people will get peak even longer than two hours w/ something like pizza that has lot of heavy grease as well as the carbs.  Or if they have any gastroparesis  issues

  • Dr. William Davis

    2/19/2011 7:05:00 PM |

    Hi, Eric--

    Sorry, but I don't know what DexCom 7 is. Can you tell me anything about it?

    Hi, Kurt--

    The effects of alcohol and alcoholic beverages are complex. The blood sugar effect is only a small part of the equation. Among the most consistent effects are reduced blood sugar with red wine, increased blood sugar with beer.

  • Dr. William Davis

    2/19/2011 7:07:12 PM |

    Hi, Anonymous--

    Impressive effort!

    Incredibly, just about any primary care doc would declare your values "normal," since you don't "need" medication.

    You've found the secret: Carbohydrates screw up health galore.

  • STG

    2/19/2011 10:54:14 PM |

    I almost had a wheat relapse today, but what I realized is that I wanted the butter. So, I ate a small bite of organic butter.

  • revelo

    2/20/2011 1:01:30 AM |

    Carbohydrates don't screw up health in most people, but they have to be managed properly. Anonymous's glucose spike occurred because he/she surprised the body with a heavier carb load than it was adapted to. It takes a week or so for the body to upregulate insulin sensitivity and glycogen storage ability. Until that upregulation occurs, high carb intake will indeed cause glucose spikes.

    Here's my own anecdote. After switching to a paleo diet for a week, I then switched back to high-carb. Upon eating 200g (dry) of cooked oats, my glucose shot up to 195 mg/dL. A week later, I was able to eat the same 200g (dry) of cooked oats and glucose remained below 120 mg/dL. What happened is that my ability to process glucose downregulated when I switched to paleo, then upregulated after I switched back to high-carb. Both the down and upregulation take a few days. It is probably inadvisable to constantly switch between paleo and high-carb. If you plan to eat high-carb, then do so consistently, so that the body is always prepared for high glucose loads.

    My recent VAP blood tests, taken after resuming my usual high-carb regimen, show HDL=66 mg/dL, LDL=61, VLDL=12, Trig=45, Lp(a)=15, HDL-2=23 (most protective HDL greater than Lp(a), thus counteracting the latter), and type A LDL pattern (mostly large buoyant LDL). CRP was .16mg/L, which is very low. Laboratory measurement of fasting glucose was 85 mg/dL, versus 84 for Reli-On Confirm home glucose testing device measured that same morning (the Reli-On device thus appears to be accurate). These results hardly suggest that a high-carb diet necessarily screws up health.

    There is also plenty of other evidence that carbs are not unhealthy for people who are lean, get daily exercise, don't have an underlying illness, and eat mostly unrefined carbs. All sorts of primitive peoples (Kitavans, Tarahumara indians, Bantus,  traditional mediterranean people's, etc) eat high-carb diets and have very low incidence of diabetes, heart disease and other chronic illnesses due to diet (they may have chronic illnesses due to parasites).

  • Might-o'chondri-AL

    2/20/2011 1:17:59 AM |

    Depression a variable: Japan 2010 journal "Anti- Aging" showed affect on blood glucose in 5 hour glucose(75 grams) tolerance test on a clinic's depressed in-patient (woman age 36). The articles authors conclude a "very low saccharide diet" is better for the brain, which runs fine on ketones.

    Fasting blood sugar = 74
    30 min post glucose = 97
    1  hour  "    "     = 78
       (coincides with insulin peak)
    2 hour post glucose = 54
       (27% below fasting blood    
    3 hour post glucose = 99
       (insulin less than 1/2 of
        30 min. insulin & 1/3 of
         2 hour insulin)
    4 hour post glucose = 75
    5 hour "     "       = 80

  • Anonymous

    2/20/2011 2:04:08 AM |

    I have a big question here.
    I persoanlly have my peak at 30 minutes. So my question is:
    Is it a BG of 140-160 after 30 minutes if after 60 minutes it is under 100 too bad?

  • revelo

    2/20/2011 2:49:20 AM |

    @Might-o'chondri-AL: Can't understand the logic of low-carb for depressed people. High-carb boosts serotonin. The only reason I could think of prescribing low-carb for a depressed person is because they are overweight, and the excess weight is partly responsible for the depression (inability to move about and exercise due to morbid obesity, for example).

  • Anonymous

    2/20/2011 6:27:17 AM |

    revelo, thanks for some sanity.  Reading these blog posts and most of the comments that follow is depressing.  They would have everyone believe that their inability to handle carbs is representative of normal, healthy, individuals.

    Maybe they need to get healthy, and then they can actually eat whole-food sources of carbs and stop being so scared and go and live life.

  • Might-o'chondri-AL

    2/20/2011 8:30:25 AM |

    Hi Revelo,
    I've got nothing against carbs & am still learning (I eat carbs); your blood profile seems excellent enough to trade for.My thinking on your approach is: that you may find, like me in my 20/30/40s + years, care free
    carbohydrates are fine and by
    the time hit 60 there's the unforseen to adjust to. The famous quote is: "Old age ain't for sissys."
    So, back to Japan ....
    Psychiatric clinic tested 2,000;
    detailed one to show how variable blood sugar/insulin expression is in depression. They claim to have got her off meds and adressed low neuro-transmitters of depression; which clinically they say (depression) is common in metabolic syndrome.

    Their flow chart for seratonin is dietary amino acid L-tryptophan as substrate with folic acid, iron, niacin and enzyme tryptophan hydroxylase; yields, 5-HTP with vitamin B6 and enzyme 5-HTP decarboxylase; yields seratonin (which in it's own right is the substrate for
    magnesium and SAMe to make into melatonin). I'll skip their GABA and dopamine flow charts.

    This was a geriatric symposium paper, so focus was on brain down the line. Their pitch was for preventing cognitive decline;
    and that ketones protect the brain from Alzheimers and Parkinsons - just as ketones diets do help in
    epilesy and other mental disorders.

    They specify that in the brain beta-hydroxy-butyrate (ketone) ups utilization of circulating oxygen more, decreases CO2 in tissues from glucose "burning", and ketones make ATP more efficiently too. As for the mitochondria, they continue to get their essential glucose molecules from gluco-neogenesis.

    My impression is they're showing that in geriatrics the potential
    accumulation of what Doc's blog
    warned about, namely  A.G.E.s
    (advanced glycation endproducts)is a risk factor for Alzheimers, etc. The authors conclusion was the central nervous system used ketones just fine;and carbohydrates were not required for old people to have good levels of circulating blood sugar.

    sowed data for 1 depressed lady

  • Anonymous

    2/20/2011 11:43:35 AM |

    Dr Davis: Two comments were made asking for your reasoning behind the suggestion for construction of a 2 hr curve. To me the comments are politely made. They are appropriate in my opinion and they deserve a response. It is obvious that you chose deliberately to ignore them.

    Your commentary is followed and I expect influences countless readers; some possibly obsessively, ie healthy individual who performed more the 75 glucose checks over a few days time.

    With your efforts to maintain this blog come added responsibilities to its readers which you currently are ignoring.

    Shame on you.

  • STG

    2/20/2011 3:47:40 PM |

    Anonymous: Your response to this blog is somewhat emotional and critical. Perhaps you could be open to the idea that some people can consume a high, unrefined carbo diet and be healthy; others will suffer adverse effects on a high carbo diet and need a more protein based or mixed diet. For those individuals that are carbo sensitive, there is good dietary advise on the blog. I do not currently test my blood sugar. I do not want to become myopic about health; however,I don't judge others on this blog who want to pursue this strategy even if they are not insulin resistant, diabetic or pre-diabetic. Moreover, I may have to resort to using a monitor in the future. The blood sugar data from another "anonymous" is very interesting and certainly provides real data for determining his or her dietary choices. Please keep an open mind and avoid insulting comments like "shame on you" which add nothing to the dicussion and are meant to insult not to educate or enlighten others.

  • Geoffrey Levens

    2/20/2011 4:38:32 PM |

    DexCom 7 is a "continuous" bg monitor for home use.

    I have been eating Dr Fuhrman's diet and lately, typical meal contains 3-4 cups chopped leafy greens, 2/3 cups cooked beans, about 2/3 oz raw seeds/nuts, 200 grams starchy root veg, one piece of fruit (most often an apple).  Peak postprandial sugars for me come very close to one hour after end of meal and are in low 120's to high hundred teens, back to fasting by 90-120 minutes Usually 90 minutes).

  • joseph

    2/20/2011 4:54:29 PM |

    why do you think that post meal levels of 120 or 140 are "normal"? Simply because are the levels that people get when eat a lot of carbs in a meal.

    You body do not like this levels, that is why it try to put them down using insulin. Why is your body doing that if they are "normal levels"?

    If you check my levels in the 4 reply you could find that when you do not eat for longs periods of time your body try keep your sugar between 70 and 90. If you are relaxed the level could be in the 70 zone and if you do some exercise it will go to 90 zone. Why your body do no increase it to "normal levels" of 120-140? Probably because this levels are not "normal".

    So you have a high carb meal. Your body react to it trying to keep your sugar down, why?. Yes... your body is stupid and doesn't have a degree in nutrition so cannot understand the science behind this "normal levels".

    When you body finally got the 85 level your dietitian says that you need to have another high carb meal. So your levels return to 120-140, and you ignorant body starts to reduce this "normal level" to 70-85. When you got that level is time to have another high carb meal, and your ignorant body returns to do the same trick.

    Years of doing that and your body cannot maintain the true normal levels your doctor says that you need to do some exercise to well... reduce sugar levels! and of course still doing 5-6 small high carb meals a day.

    So now you need to run the New York City Marathon to get rid of all that carbs in all that meals your are eating during the day.

    Of course you need increase the carbs in these meals to have energy to do all that exercises. In one of those healthy marathons you also take a high carb drink to... well... you know.

    It doesn't work, you end eating more than before because your body needs more energy to run all that healthy marathons and you are all the day hungry.

    Later your unscientific and stupid  pancreas collapse and your doctor says that you need to maintain your 34646464 high carbs meals a day, but take some insulin to help your body to reduce all the sugars YOU ARE EATING EVERY 3 HOURS.

    Probably our pancreas simply commit suicide because is not able to understand our rock solid science.

  • Anonymous

    2/20/2011 5:15:30 PM |

    Can someone explain to a non-scientist what "up-regulate" and "down-regulate" mean?  Peter

  • Anonymous

    2/21/2011 1:38:04 AM |

    A couple of people have asked why construct your own glucose curve so I thought I'd throw out my thoughts on it.  Every person's glucose will peak at different points either due to slower stomach emptying or a slower absorbed carb or whatever. I have read that many people will peak at 75 minutes.  So if you are trying to get a real idea as to how your body reacts to glucose/insulin then you need to test frequently to find YOUR personal peak.  Then you will know when to test when you try new foods.  Is that others understanding too?

  • Anonymous

    2/21/2011 3:21:29 AM |

    This blog post is so full of Fear, Uncertainty, and Doubt.  People asking questions due to being scared by Dr. Davis' suggestion of "constructing your glucose curve", so they ask him questions in the comments, like what their "glucose curve" should look like.  People thinking now they better be jabbing themselves 15 times after a meal.  Thinking about a meal for hours after a meal.  Guilt for eating that meal.

    So Dr. Davis' response?  IGNORE THEM and put up a new blog post with MORE scare-mongering:

    Now you should fear the banana!

    "Would you like a banana?"

    What a joke.  Show us a single person who got fat off of bananas OR potatoes, or any whole food carbs.

  • Might-o'chondri-AL

    2/21/2011 5:10:31 AM |

    Hi Peter,
    Up-regulate is an action on a gene that makes it do more of what it's capable of doing. And down-regulate is when a gene is being acted on in a way that it will do less of what it's capable of doing.

    A gene can be overactive or underactive. Depending on the dynamic, of how a specific gene ideally should be doing, regulation up or down is desired.

  • eye lift guide

    2/22/2011 9:34:34 AM |

    Here is giving nice tips. Thanks for its. I the way you explain us.

  • Dr George

    3/29/2011 7:35:53 AM |

    Hey there Dr Davis,

    Created my own glucose curve as part of my own research and actually got a bit of a scare!

    I was doing a high carb meal to try and demonstrate an early carb spike then drop.

    While I didn't get the response I was looking for I got something a bit scarier. A fasting glucose indicitive of pre-diabetes reading instead. I am amazed how one bad meal was able to send my sugar awol over night.

    Back onto low carbs for me.

    Thanks for helping open my eyes to my potential diabetes.

    Dr George