Physicians focus so much on disease that we sometimes lose sight of what’s healthy and normal. For instance, the American Diabetes Association defines “tight” control of diabetes to include sugar levels as high as 179 mg/dl (9.94 mmol/l) when measured two hours after a meal. In contrast, young adults without diabetes two hours after a meal are usually in the range of 90 to 110 mg/dl (5.00–6.11 mmol/l).
What Is a Normal Blood Sugar Level?
The following numbers refer to average blood sugar (glucose) levels in venous plasma, as measured in a lab. Portable home glucose meters measure sugar in capillary whole blood. Many, but not all, meters in 2010 are calibrated to compare directly to venous plasma levels.
Fasting blood sugar after a night of sleep and before breakfast: 85 mg/dl (4.72 mmol/l)
One hour after a meal: 110 mg/dl (6.11 mmol/l)
Two hours after a meal: 95 mg/dl (5.28 mmol/l)
Five hours after a meal: 85 mg/dl (4.72 mmol/l)
(The aforementioned meal derives 50–55% of its energy from carbohydrate)
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Ranges of blood sugar for young healthy non-diabetic adults:
Fasting blood sugar: 70–90 mg/dl (3.89–5.00 mmol/l)
One hour after a typical meal: 90–125 mg/dl (5.00–6.94 mmol/l)
Two hours after a typical meal: 90–110 mg/dl (5.00–6.11 mmol/l)
Five hours after a typical meal: 70–90 mg/dl (3.89–5.00 mmol/l)
Blood sugars tend to be a bit lower in pregnant women.
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What Level of Blood Sugar Defines Diabetes and Prediabetes?
According to the 2007 guidelines issued by the American Association of Clinical Endocrinologists:
Prediabetes: (or impaired fasting glucose): fasting blood sugar 100–125 mg/dl (5.56–6.94 mmol/l)
Prediabetes: (or impaired glucose tolerance): blood sugar 140–199 mg/dl (7.78–11.06 mmol/l) two hours after ingesting 75 grams of glucose
Diabetes: fasting blood sugar 126 mg/dl (7 mmol/l) or greater
Diabetes: blood sugar 200 mg/dl (11.11 mmol/l) or greater two hours after ingesting 75 grams of glucose
Diabetes: random (“casual”) blood sugar 200 mg/dl (11.11 mmol/l) or greater, plus symptoms of diabetes
If there’s any doubt about the diagnosis, testing should be repeated on a subsequent day.
Compared to impaired fasting glucose, impaired glucose tolerance may be a better predictor of cardiovascular disease and death. So some researchers and clinicians focus on preventing high blood sugar swings after meals. The problem with prediabetes, which causes no symptoms early on, is that one of every four cases progresses to full-blown diabetes over the next 3–5 years.
The numbers above do not apply to pregnant women. Five percent of pregant women develop gestational diabetes that goes away soon after delivery.
What Level of Hemoglobin A1c Defines Diabetes?
Another way to consider normal and abnormal blood sugar levels is to look at a blood test called hemoglobin A1c, which is an indicator of average blood sugar readings over the prior three months. The average healthy non-diabetic adult hemoglobin A1c is 5% and translates into an average blood sugar of 100 mg/dl (5.56 mmol/l). This will vary a bit from lab to lab. Most healthy non-diabetics would be under 5.7%.
In December, 2009, the American Diabetes Association established a hemoglobin A1c criterion for the diagnosis of diabetes: 6.5% or higher. Diagnosis of prediabetes involves hemoglobin A1c in the range of 5.7 to 6.4%. The aforementioned blood sugar criteria can also be used.
What Are Blood Sugar Goals During Treatment For Diabetes?
The 2007 guidelines of the American Association of Clinical Endocrinologists “encourage patients [both type 1 and 2] to achieve glycemic [blood sugar] levels as near normal as possible without inducing hypoglycemia [low blood sugar].” Specifically:
Fasting blood sugar: <110 mg/dl (6.11 mmol/l)
Two hours after a meal: <140 mg/dl (7.78 mmol/l)
Hemoglobin A1c: 6.5% or less
The American Diabetes Association recommends normal or near-normal blood sugar levels, and defines “tight control” as:
1) pre-meal and fasting glucose levels of 70–130 mg/dl (3.89–7.22 mmol/l)
2) sugars under 180 mg/dl (10.00 mmol/l) two hours after start of a meal
3) hemoglobin A1c under 7%.
A hemoglobin A1c of 7% is equivalent to average blood sugar levels of 160 mg/dl (8.89 mmol/l). Hemogobin A1c of 6% equals, roughly, average blood sugar levels of 130 mg/dl (7.22 mmol/l). But remember, healthy non-diabetics spend most of their day under 100 mg/dl (5.56 mmol/l) and have hemoglobin A1c’s around 5%.
Diabetic experts actively debate how tightly we should control blood sugar levels. For instance, Dr. Richard K. Bernstein—a type 1 diabetic himself—recommends keeping blood sugar levels under 90 mg/dl (5.00 mmol/l) almost all the time. If it exceeds 95 mg/dl (5.28 mmol/l) after a meal, then a change in medication or meal is in order, he says.
Here’s the over-simplified “tight control” debate. On one hand, tight control helps prevent and may reverse some of the devastating consequences of diabetes. On the other hand, tight control in diabetics on insulin and certain other diabetic medications may raise the risk of life-threatening hypoglycemia and may shorten lifespan in other ways.
Blood Sugar Goals For My Personal Diabetic And Prediabetic Patients
Ideally, normal glucose levels before and after meals, with normal hemoglobin A1c.
Realistically, these are acceptable fall-back positions:
Fasting blood sugar: under 100 mg/dl (5.56 mmol/l)
One hour after meals: under 150 mg/dl (8.33 mmol/l)
Two hours after meals: under 130 mg/dl (7.22mmol/l)
Hemoglobin A1c: 6% or less
Treatment options for those not at goal include diet modification, weight loss, exercise, and medications. Admittedly, those goals are not acceptable or achievable by everyone with diabetes. Future studies may prove that such strict goals are not necessary to avoid the complications and premature death suffered by people with diabetes. Tight control may be less important for elderly diabetics over 65–70. But for now, if I were a young or middle-aged diabetic I’d shoot for the goals above.
Technical Notes
The gold standard for measuring glucose is a large chemistry analyzer in a lab, which measures values in plasma obtained from a vein with a needle. The glucose level in capillary whole blood, obtained via fingerprick and analyzed on a portable/home glucose monitor, is a different value, often 5–10 mg/dl higher than venous glucose. As of 2010, a majority of home glucose monitors, but not all, are calibrated so as to be directly comparable to venous plasma glucose readings. Read your monitor’s paperwork to find out about your device.
Portable fingerstick glucose meters are not as accurate and as you might expect. If your actual glucose level is 100 mg/dl, the meter may report it as 80 or 120 or anywhere in between, for example. The meters tend to be less accurate at glucose values over 200 mg/dl. Some devices are definitely more accurate than others. Research the available devices before you acquire one.
Outside the U.S., glucose is usually reported in units of mmol/l (millimoles per liter). One mmol/l = 18 mg/dl. To convert mg/dl to mmol/l, divide by 18 or multiply by 0.055.
Last updated June 1, 2010
I’ve read several articles and often mentioned is that Diet Sodas/Aspartame
can CAUSE lots of various diseases such as diabetes, rashes, etc. Have you done any research on this??? I do consume up to 5 cans a day and have been recently told I have diabetes. No one in my family has ever had it.
BJ, I’ve not studied that issue. I personally limit my diet sodas to two daily, and many days I drink none. I tend to doubt there’s an unrecognized epidemic of illness caused by aspartame.
-Steve
my glucose tested 116 with fasting blood test is that normal i am 69?
I am almost 65 and from what I just read its not that important for me to have the tight tight control? I am almost anal in keeping my bs below 120 2hrpp and 140 1hrpp I am on a low carb of 50 or so carbs a day. Am I going overboard? Thanks Karen
Hi, Karen.
It’s an extremely complicated situation. Be sure to get your own doctor’s opinion.
Over the last few years, we’ve seen published studies suggesting that the average diabetic may have a better overall outcome, at least in terms of longevity, with hemoglobin A1c’s in the range of 6.5 to 7%, not lower. If you successfully achieve your goal glucose levels, you’d be in the 5 to 6% range.
It’s difficult to be sure about this issue because of the multitude of issues involved, such as type 1 vs type 2 diabetes, underlying type of diet, co-existing illnesses, access to medical care, types on non-drug adjunctive medical care, exercise vs sedentary lifestyle, geographic location, which diabetic drugs are being used and for how long, etc. For instance, the ACCORD trial indicated higher death rates in diabetics with hemoglobin A1c under 7%. But ACCORD participants, at least some of them, were using rosiglitazone. Rosiglitazone was esssentially taken off the market in the U.S. a year ago because of excess cardiac deaths in users.
In the ideal scientific study, we alter ONE variable and see what happens. It’s often hard to do that in clinical studies on humans.
-Steve
Thanks for your information. I have listened to you on Jimmy Moore’s podcasts and have also written about your work on livestrong.com.
I am actually diagnosed with PCOS and although I am just slightly overweight, I discovered that my 2-hr post-meal blood glucose levels were at 124 mg/dL after a meal of fish, non-starchy vegetables, butter and 2 squares of 85% dark chocolate (for a total of less than 12 g of carbs) (fasting BG ranges between 76 to 88 mg/dL, except for last night when they went up to 115 mg/dL while suffering from insomnia around 4am). I am currently eating a very low-carb diet, with <50 g of available carbs a day and believe that my blood sugar levels should not go that high after eating. What kind of target would you aim for? I am still trying to lose weight and manage my PCOS. Should I restrict my carbs even more?
Hi Aglaee. Thanks for chiming in.
For legal and medical reasons, I can’t be specific about your situation since I don’t have the full picture and haven’t examined you. Be sure to work with your own personal physician.
Nevertheless, if those were my numbers, I would’t be too terribly concerned. I wouldn’t cut my carbs any further at this point. I might get a 75-gram oral glucose tolerance test (after three days of eating at least 100-150 g of digestible carbs daily). That would tell me if I were in the prediabetic or diabetic range (at which point I’d have more concern).
An exercise program with both aerobic and resistance training components may help reduce after-meal blood sugar levels.
Hope this is helpful.
-Steve
This is some very helpful information, thank you! I also have PCOS, 33 yrs, and a type II Diabetic on Metformin 500 x 2/day. (I also take Prometrium 12 days out of the month) I am obese and have been taking losing weight very seriously. I have noticed a slight trend where my fasting was 121 (It has never been that high), and then two hours after breakfast it will be around 105. I was sure to retest each time to see if I had a faulty test, and they were correct. Have you had cases where diet and excercise have altered blood sugar like this? I’m use to having a fasting blood sugar of 85-100, and 2 hour post breakfast of around 115. I have a doctors appointment on the 15th, but I would appreciate any input or advice you could give. Thank you!
Hello, Becky.
I can’t give you any personal advice since I’m not your personal physician. But I do have a few comments.
You may be exhibiting the “dawn phenonmenon.” Here’s how it works. Insulin helps to keep blood sugar levels from rising too high. Everybody’s llver helps to deactivate insulin. For mostly mysterious reasons, some livers work more effectively to deactivate insulin in the early morning hours. Deactivation of insulin would allow blood sugars to rise, particularly fasting (early AM) levels. Eating breakfast then “wakes up” the pancreas so it produces more insulin. How to lower fasting glucoses under 100 mg/dl? An exercise program can help. Also eating relatively fewer carbs with the evening meal might help, moving those to earlier in the day, say lunchtime. There are a few other tricks, too.
The dawn phenomenon effect may last till mid- or late-morning for some folks. I think that’s why Dr. Richard Bernstein recommends eating ony 6 g of digestible carb for breakfast, and 12 g for both lunch and dinner.
Hope that helps.
-Steve
after break fast by 80 min my suger level is 116. iam not taking any tablate
Please tell me iam diabetes patients or not ?
Hi, Rakesh. Sorry, but I can’t make any diagnosis or provide medical advice over the Internet. Check in with your personal physician.
-Steve
WHAT IS THE NORMAL BLOOD SUGAR LEVEL & WHAT SHOULD BE MY DAILY DIET
I have a Ac1 level of 5.4. I am 30 years old, have not been active for 6 months but am willing to restart today my training. Is 5.4 a good level?
Hi,
Does this look normal to you for an OGTT?
HBAC1 : 5.2
Fasting : 5.1
C-peptide : 1.50 (1.06 – 3.53, Peak: 4-10)
Insulin : 5.23 (4-16 fasting)
1 Hr : G 10.3 (ref 6 – 9.4), Insulin 15 ulU/ml (4=16 fasting)
2 Hr : G 6.5 (ref 4 – 7.4), Insulin 9.28 ulU/ml (4-16 fasting)
Thanks…
This web site sucks!!!!
on 12/3/12 at about 1300 hrs. Blood glucose after 5 hrs. fasting it was 67mg/dl and 2 hrs after meal it was 160 mg/dl . am i glucose patient
I’ve just discovered this website and finally some light sheds on issues lately: whenever I eat, I feel like I am drugged afterwards(never tried, but I assume that’s how it is), I get EXTREMELY tired, sweaty, nauseated, can’t see well, can’t think at all and I just HAVE to lay down. If I can’t lay down, I go on beat for hours until I feel normal again. I discovered this: my pulse goes very high, in the 90′s after I eat, my blood pressure goes higher, 117/74(but normally is very low, like 90/55). Then, my sugar readings were: 116 before eating, then 1h after eating and 2h after eating is 146. Would I be considered a pre-diabetic? I am only in early 30′s, but we’ve been through a lot of stress past years, had four kids one after another, gained ~20lb… We eat pretty healthy, no processed foods, no sodas, no sugars, unless it comes from fruit. There are some diabetes and heart issues in the family history.
1h after eating was 154. I missed on writing it. Do I have reasons to be concerned?
Second day update: after lunch 1h: 197, after lunch 2h: 193.
Good to hear from you, blogger141.
If those are your blood sugar readings (in mg/dl) while you’re feeling so bad, you can’t attribute the symptoms to blood sugar levels. You better check in with your personal physician for an accurate diagnosis.
-Steve