More on blood sugar

Take any of the following foods:

One chicken breast
Quarter-pound ground beef
6 oz salmon steak
½ cup raw almonds
3 eggs scrambled in olive oil

How much is blood sugar increased by any item in the above list?

If you said virtually zero, you’re correct. Eat any of these foods, regardless of portion size, and blood sugar won’t change substantially. If you started with a blood sugar of, say, 90 mg/dl, 1-2 hours later it would be 90 mg/dl. It might go up or even down a few milligrams, but for all practical purposes it remains substantially unchanged.

How much is blood sugar increased by the foods in this list:

2 slices multigrain bread
1 whole wheat bagel
4 oz high-fiber breakfast cereal
2 whole grain pancakes, 2 oz maple syrup

The foods in this list are a different story from the first. Depending on your body weight, exercise habits, and other factors, a typical blood sugar response in an otherwise healthy non-diabetic person would be 120 mg/dl to 160 mg/dl. In someone with diabetes, it could easily exceed 200 mg/dl.

That isn’t good. Large blood sugar excursions to 140 mg/dl have been clearly associated with greater risk for heart attack, progression to diabetes, inflammatory responses, and other adverse health effects. In fact, blood sugars as low as 100 mg/dl after eating have been associated with increased cardiovascular risk.

Then why are the USDA, American Heart Association, the American Dietetic Association, and the American Diabetes Association telling us to eat more of the foods that shoot blood sugar up to such high levels? “Eat more healthy whole grains”?

To see how much the issue of exaggerated blood sugars after eating applies to you, a simple blood sugar check 1-2 hours after eating can show you. Either your doctor can have the test drawn or you can purchase your own inexpensive glucose meter (e.g., Walmart, Wagreens).

My prediction: You will be very surprised at blood sugar responses after common foods, including “healthy whole grains.” And, by the way, keeping blood sugar excursions to a minimum will facilitate weight loss.

Comments (36) -

  • Anonymous

    1/25/2010 5:20:16 PM |

    Dr. Davis,

    Does the context of a mixed meal blunt the impact of some of those grain choices listed? For example, if you have someone who consumes a lean source of protein and some fibrous vegetables at a meal but also happened to add a bagel or a slice or two of bread, would there be the same exaggerated response or would it be lessened on account of the protein and added fiber?

    Or in the case of protein and a source of quality, undamaged fat, would this also mitigate the impact at all?

    I'm not looking for a license to eat grains and such, just curious if the impact is at all close to what it is in someone who ate the grains or the pancake/syrup combo as a standalone as a standalone.

    ~Ralph Backstrom

  • Laura

    1/25/2010 7:10:51 PM |

    I started checking my post meal glucose last Saturday.  So far, the only thing that raised it was the diluted cup of fruit juice.  I don't drink juice any longer and this provided some evidence as to why.

    Thanks for the wisdom!

  • Anonymous

    1/25/2010 7:35:04 PM |

    Behold the power of the dominant paradigm.  Go to Google and you find:

    2,160,000 for "whole grain"
    1,770,000 for "healthy whole grain"
    502,000 for "heart-healthy whole grain"

    4,980,000 for saturated fat/fats
    524,000 for "limit saturated fat"
    245,000 for "artery-clogging saturated fat"
    206,000 for "unhealthy saturated fat"

    And the voices in the wilderness
    152,000 for "healthy saturated fat"


  • Anonymous

    1/25/2010 7:50:31 PM |

    Alas, this is only true for someone who doesn't already have T2 diabetes.  I am a small woman, 5'2", weighing about 120 pounds.  If I ate 6 oz of salmon at one sitting my blood sugar would easily go to 130 at the least, and would stay high for awhile --and I'd be insulin resistant for a day or so after. I can handle only 3 ounces of protein food at a time, and even then I get some rise.

    But your point is well taken for someone who can handle larger portions.

  • lindaharper

    1/25/2010 7:57:56 PM |

    You are so correct.  I really try to eat properly for my diabetes doing this very thing and testing what raises it and what does not.  I recently got home from a trip with family where I could not control my eating but I still kept track of my blood sugars.  I was shocked at what changing my diet did to me for those few days (while still taking some diabetic medication).  I am so glad to be home so I can eat properly!

  • Kurt

    1/25/2010 9:12:40 PM |

    And checking your blood sugar helps you determine your individual response to different foods. For example, my blood sugar increases more when I eat rice than when I eat potatoes, even when the amount of carbs is the same.

    Using a glucose meter, I have been able to keep my postprandial glucose under 120 mg/dl. Thanks for the suggestion.

  • I Pull 400 Watts

    1/25/2010 9:39:53 PM |

    What are your thoughts on fruit and veggies. With their effect on BG and a low carb diet, are you recommending lowering those as well? The only problem I have with a low carb diet is it may mean low fruit and vegetables as well.

  • Dr. William Davis

    1/25/2010 11:43:42 PM |

    Hi, Ralph--

    It does indeed. However, the effect of the precise mix of foods and portions can be best gauged by checking your postprandial blood sugars to be certain.

  • Dr. William Davis

    1/25/2010 11:44:18 PM |

    Hi, Freya--

    That's fabulous!

    It offers an interesting insight into what the "masses" are thinking.

  • Katelyn

    1/26/2010 1:25:16 AM |

    We don't need fruits and vegetables at all, particularly the former. Fruit are sugar bombs with trace nutrients.

  • steve

    1/26/2010 1:39:08 AM |

    is it really necessary to do this if you do not eat grains except ground flax with a diet of vegetables, meat fish, chicken and Greek yogurt such as Fage and only a handful of berries a couple times a week with a Whey protein shake?

  • Anonymous

    1/26/2010 5:45:09 AM |

    I think some of us are going a bit overboard on the anti-fruit/vegetable crusade here.  It is impossible to eat too much kale, broccoli, and other greens.  Vegetables are the healthiest things you can eat, and I've made them the center of my diet.  Fruit jucies are dangerous, definitely.  (I wish I knew that when I was younger.)  But fruits, I think, are much, much better, because of the fiber content. Really, eating a bowl of blueberries, and apple, and a banana is not going to give you diabetes, and will do far more good than harm.  

    - Vladimir

  • Anonymous

    1/26/2010 11:30:17 AM |

    So what about 4 oz of rolled oats?

    I avoid 95% of grains except for oats.

    Here they claim that oats are low- glycemic...

    Others say that oats do not have gluten...or at least not the same type as in wheat.

    If one would avoid all fruits...vegs...grains...that would be a carnivore's diet?

  • Kamila

    1/26/2010 1:40:09 PM |

    Dr Davis,

    You have been writing about the benefits of a low-carb diets for yeears.  So why is only now that it "mainstream" doctors are catching up.  This article from BBC News:

    Low-carb diet 'heart benefits'
    A low carbohydrate diet, like Atkins, is better at cutting blood pressure than weight loss drugs, according to US research.

    In this related article, the efficacy of the "high-carb" DASH diet when used alone for the control of high blood pressure is questioned:

    Weight management needed for DASH diet to optimize heart health

    In overweight individuals with hypertension, the health benefits of the DASH (Dietary Approaches to Stop Hypertension) diet can be substantially increased by weight loss and exercise, according to early results of the ongoing ENCORE study.

    National guidelines for controlling high blood pressure (BP) recommend the DASH diet, which is high in low-fat dairy products, fruits and vegetables, lower in fats, and rich in fiber. However, studies in "real life" situations have questioned its value independent of other lifestyle changes.

  • Dr. William Davis

    1/26/2010 2:10:32 PM |


    Please don't regard to "no fruits and vegetables" as my advice. I believe that vegetables and SOME fruit should be the core of your diet.

    You can always know whether a specific carbohydrate food is good for you if you check your one-hour after eating blood sugar. That will tell you for certain.

  • Laurie

    1/26/2010 8:58:30 PM |

    So, I have been eating very low carb for a few months now.  I don't have type 2 diabetes, but I am trying to lose weight, and my research is leaving me with NO doubt as to the importance of low carb eating.  My son is type 1 diabetic, so we have several meters lying around, unused.  

    Since starting low carb, I haven't really checked my blood glucose readings.  But, when I read your last two blog posts, I had just eaten a low carb lunch about an hour previous.  So, I checked my blood glucose and it was 79 mg/dl.  Perfect!

    I was curious how high it would be if I ate a high carb meal.  But since I hardly ever do that anymore, I didn't know when I'd get a chance.

    Today I got my chance.  I went out to eat with my husband to a Japanese restaurant.  I ate rice, tempura shrimp, and a salad dressing that had some sugar in it.  So, after I got home, I checked my blood glucose at 1 hour postprandial, and guess what it was...167 mg/dl!  I was very surprised to see it that high!  I checked again at 2 hours postprandial, it had dropped to 140 mg/dl.  

    So, are those pre-diabetic numbers?

    In any case, I'm glad that I'm not eating that way anymore.  I'm down almost 20 lbs, and I feel great.  I'm totally convinced that the world needs to hear your message!

  • Flowerdew Onehundred

    1/27/2010 12:24:17 AM |

    Bought a blood sugar meter on your recommendation, and it's been informative.  I found out why I can't do intermittent fasting without feeling like crap - BG was 63 before my meal!!!

  • Anonymous

    1/27/2010 1:15:01 AM |

    Laurie, I'm not an expert, but I don't think you've got enough data to know.  If you began eating rice daily, and your numbers didn't normalize, then yes, there's a problem.  However, I'm uncertain what, if anything, you'd need to do about it, given that your typical way of eating probably doesn't spike glucose.

    Yesterday's high readings are probably the result of 2 things: (1) an unprepared pancreas, and (2) physiologically insulin resistant muscle tissue.  

    Your pancreas uses the past as a predictor of the future.  On a low carb diet, your pancreas assumes that it won't need much insulin for the next meal.  It doesn't have a large stockpile waiting just in case you decide to eat high carb one day.  

    So a pancreas used to a VLC diet won't be prepared to prevent a blood sugar spike if you eat an unusual meal.  

    However, if you ate higher carb for a few days, a healthy pancreas would start making more insulin.  At that point, the spike from a rice & tempura meal would (hopefully!) be lower.

    Also, when your diet is low enough in carbs, your muscles become insulin resistant.  This is referred to as physiological or peripheral insulin resistance, which is not the same as pathological type II diabetes-causing insulin resistance.  

    When VLC, your muscles are being fueled by fatty acids, and they don't need much glucose, so they stop accepting it from your bloodstream.  Muscle insulin resistance may also help to conserve scarce glucose for your brain and red blood cells.

    Assuming that you're nondiabetic, if you ate higher carb for a while, that type of insulin resistance should reverse.

    Clear as mud?  Laughing

  • Anonymous

    1/27/2010 3:02:35 PM |

    I have a question pertaining to what the above poster said about about physiological or peripheral insulin resistance.  I believe that this is what I experienced while on a low-carb diet.  After several months, my fasting blood sugars had risen to readings in the upper 110s and even low 120s.  Throughout the course of the day, they would hover around 100.  Previous to beginning the low-carb diet, my fasting blood sugars were typically in the upper 80s to low 90s, but my one-hour postprandial sugars would rise to 140 or higher with a meal containing a moderate to high amount of carbs.

    So my question is, if this type of insulin resistance can occur even when keeping carbs to a minimum, how can that be healthy in the long-term if even sugars in the 100s can cause problems?

  • Anonymous

    1/27/2010 4:41:29 PM |

    (Apologies if this is a duplicate submission.  I got an error the first time I hit the publish button.)

    Peter over at Hyperlipid has written about physiological insulin resistance and fasting blood sugar.

    He's written other posts on the topic as well, which you can find by scrolling down to the labels section on the right hand side of the blog.

    Peter's argument may explain your fasting blood glucose, but that doesn't necessarily mean everything is okay.

    What is your HbA1c?  If your A1c is at or above 6%, you might want to refer to an older post on this forum (link below) and/or Bernstein's book on diabetes.

  • Anonymous

    1/27/2010 10:15:51 PM |

    I think you should clarify things a bit. Protein certainly does get converted to glucose via gluconegenesis, and the incretin process will give you a bit of a sugar rush as well per Dr, Bernstein. Us type 1's attempting low carb lifestyles know very well that BGs most definately are affected by all consumed foods.


  • Vladimir

    1/28/2010 8:42:23 AM |

    I am really confused here now.  Dr. Davis' post says that eating beef won't raise blood sugar.  But Drs. Oz & Roizen, the authors of the "You" series, and who strike me as learned and straightforward fellows, not captured by any particular industry, say that *saturated fat* -- whether from animals or coconuts or palm trees --  causes insulin resistance.  If that's right, then eating beef and other saturated fats will reek havoc on blood sugar -- if not now, then later.  

    So what gives?  Who is right?  Is the science just hopelessly confused at this point?

  • Fred

    1/28/2010 4:22:45 PM |

    For T1 and T2 diabetics:

    See Dr. Richard Bernstein's book "Diabetes Solution" for the ultimate low carb eating plan.  He advocates 30 grams of carbs per DAY - sounds extreme but he's been living with T1 diabetes (juvenile, insulin dependent) for 64 YEARS!

    Good luck


  • malpaz

    1/29/2010 7:58:20 PM |

    im consfused too... so if saturated fat causes insulin resistance(which precedes or follow leptin resistance), and protein will spike blood sugar...

    makes meat sound like the WORST of both world... im so confused

  • Dr. William Davis

    1/30/2010 2:31:16 PM |

    A clarification: Protein and fats, including saturated fats, DO increase blood sugar. However, the magnitude of effect is much smaller than that of carbohydrates.

  • Vladimir

    1/30/2010 6:03:42 PM |

    Now I'm starting to understand why you're against grazing, Dr. Davis!  It seems like not eating for several hours -- i.e., sticking to meals -- would be quite helpful in keeping blood glucose down.

  • stcrim

    1/30/2010 8:34:43 PM |

    Dr. Davis,

    I've heard and read that sprouting grains (and beans) changes their starch content into a vegetable sugar making them much safer.  Some examples are 100 percent sprouted breads like Ezekiel Bread.

    Any truth to this that you know of???


  • Kamila

    1/31/2010 12:51:52 AM |

    Dr Davis,

    Another article on the dangers of a "low-fat" diet:

    "While we've all been brainwashed into thinking that fat is the killer we must avoid and food manufacturers bring out more and more profitable 'low-fat' versions of foods, starch - in the shape of pasta, bread, cereals, potatoes and rice - has been quietly adding on the pounds, while we are being told that it's good for us."

  • Kamila

    1/31/2010 12:57:40 AM |

    The article title is:

    The Big Fat Lies about Britain's obesity epidemic

    "While it showed some benefits from cholesterol-lowering drugs, the assumption made by the researchers was that if you eat a diet low in cholesterol, that would have the same effect as taking cholesterol-lowering drugs.

    This conclusion prompted various agencies in the U.S. to start a campaign to lower the amount of saturated fats in our diet.

    At no time did this study look at the effect of saturated fats on heart attacks or heart disease.

    So, on the basis of a study looking at drugs lowering cholesterol, we ended up with a message to eat less saturated fat.

    This plea for sanity over the advice on fats is not a lone cry.

    Several very influential experts such as Dr Laura Corr, consultant cardiologist at Guys and St Thomas' Hospital in London, and Dr Michael Oliver, from the National Heart and Lung Institute, have asked those in power to stop propagating an unproven message.

    Where does the FSA find such certainty among the pile of published science which is not conclusive in its findings?

    In fact, there are some statistics showing quite the contrary, especially when mixed with a low- starch and low-sugar diet.

    One report looked at 27 individual studies into the link between fats and heart disease and no link could be found."

  • stcrim

    2/2/2010 1:14:44 AM |

    The following are my cholesterol and Triglyceride numbers from 1-13-10 and 1-30-10 (dates are when the reports were issued.

    I am a male 54 year of age and considered myself in fair shape at 5’8” and 184lbs.   My starting total cholesterol was 295, LDL was 200, HDL was 46 and my VLDL was 49.  Triglycerides were 242.  Two weeks later my total cholesterol is 156, LDL is 102, HDL is 32, and VLDL is 22.  My Triglycerides are 109.

    My doctor is a huge fan of Dr. Davis.  Dr. Brock outlined a program for me that includes 10,000IU of Vitamin D (my values 2 weeks ago were 28.6, was not taken this time), one tablespoon of Carlson’s Fish Oil, K and K2 complex and magnesium.  There are several other nutrients such as mixed Vitamin E included

    On top of that I have modified my diet to a more plant based, lower saturated fat plan.

    This is where is may become a little controversial.  From what I understand, none of the above could account for a Drop from 295 t o156.

    Though my Doctor, like Dr. Davis feels the jury is still out, I decided to take 1400mg of disodium EDTA every morning and have those 2 weeks.  My goal in taking the EDTA was not to clean out calcium.  I understand that it doesn’t do that as far as anyone knows.   I had read multiple times that it lowers cholesterol and normalizes blood platelet aggregation.  

    Since there appeared to be little or no risk it seemed worth a try.  I can’t say that EDTA was the reason for such good numbers now but I also can’t find any other reason for them.  The only cholesterol test I had done before those 2 was 7 years ago and my total was 270.  295 two weeks ago and 156 today.

    I’m not posting this to drive the EDTA controversy.  I believe the second chance I have been given is a combination of Dr. Davis and Dr. Brocks research for which I am hugely grateful.  If EDTA had anything to do with the numbers so far, I also have Dr. Garry Gordon to thank for his research.

    A year from now I plan to have a second CT scan.  As you might guess my CT score was not go.  I was in the top 10 percent for my age.  Scary given that my grandfather died in 1932 of “acute indigestion” (wink) and my father died in 1989 of a heart attack.

    Thank you Dr. Davis.  By the way, Dr. Brock would not let me leave is office without a copy of “Track Your Plaque”.


  • Santiago

    2/5/2010 1:46:59 AM |

    I bought the onetouch mini today and Im gonna do some pre-post eating tests next week.
    One thing I noticed is the manual says that after a meal the samples taken from a finger can be as much as 70 mg/dl higher than samples taken in a lab. Adding this to the 20% accuracy means that getting a 150 mg/dl after a meal with this device could be 50 mg/dl if tested in a lab

  • jpatti

    2/6/2010 3:13:47 PM |

    Protein raises bg.  I use insulin and have to use half as much for protein as for carbs; i.e. 1 unit Novolog covers 5g carb or 10g protein.

    Both protein and fat can be converted to glucose via gluceoneogenesis.  

    However, in practical experience, fat has no effect except to slow the raise caused by carb and protein (the "peak" bg after a fatty meal occurring later than for a lower-fat meal).

  • Anonymous

    3/29/2010 12:20:48 AM |

    Whoa! Not only does protein raise BG (via gluconeogenesis), but for someone on a low-carb diet, their average BG (and A1C) will be dominated by the glucose produced by protein. In fact, this is why advanced diabetics cannot ultimately control their condition by low-carb diets alone - the protein they need to survive is enough to raise their BGs to unacceptable levels.

  • C. Holesterol

    6/28/2010 6:47:14 AM |

    Stress is always a very big factor in stimulating all diseases as they arise from the mind.salt and sodium in excess also leads to many diseases of the body.

  • buy jeans

    11/3/2010 3:18:01 PM |

    That isn’t good. Large blood sugar excursions to 140 mg/dl have been clearly associated with greater risk for heart attack, progression to diabetes, inflammatory responses, and other adverse health effects. In fact, blood sugars as low as 100 mg/dl after eating have been associated with increased cardiovascular risk.