Blood sugar targets established by the American Diabetes Association are far too high and do not protect people from developing heart disease, diabetes, or other complications. And we looked at what the scientific literature indicates are safer targets for fasting blood sugar, hemoglobin A1c, and either OGTT or post-meal blood sugar.
On the other hand, we also discussed the importance of context: why it’s important not to rely on a single blood sugar marker, and how healthy people can sometimes have blood sugar spikes above 140 mg/dL one hour after a meal. Please keep this in mind as you read through the rest of this article.
In this article, I’m going to introduce a simple technique that, when used properly, is one of the most effective ways to maintain healthy blood sugar and prevent cardiovascular and metabolic disease – without unnecessary drugs.
I love this technique because it’s:
- Cheap. You can buy the equipment you need for $16 online.
- Convenient. You can perform the tests in the comfort of your home, in your car, or wherever else you might be.
- Personalized. Instead of following some formula for how much carbohydrate you can safely eat, this method will tell you exactly what your carbohydrate tolerance is, and which carbs are “safe” and “unsafe” for you.
- Safe. Unlike the oral glucose tolerance test (OGTT), which can produce dangerous and horribly uncomfortable spikes in blood sugar, this strategy simply involves testing your blood sugar after your normal meals.
The strategy I’m referring to is using a glucometer to test your post-meal blood sugars. It’s simple, accessible and completely bypasses the medical establishment and pharmaceutical companies by putting the power of knowledge in your hands.
It’s one of the most powerful diagnostic tools available, and I use it with nearly all of my patients. Here’s how to do it.
Step one: buy a glucometer and test strips
A glucometer is a device that measures blood sugar. You’ve probably seen them before – they’re commonly used by diabetics. You prick your finger with a sterilized lancet, and then you apply the drop of blood to a “test strip” that has been inserted into the glucometer, and it measures your blood sugar.
There are literally hundreds of glucometers out there, and their accuracy, quality, and price vary considerably. The one I recommend to my patients is called Relion Prime, which can be found at Walmart.com. (Note: as a rule, I don’t like to support Walmart, but I haven’t been able to find this unit anywhere else at a similar price.) Even better, the test strips, which you’ll need on an ongoing basis to monitor your blood sugar, are relatively cheap for Relion Prime. You can get 50 of them for $9.00 at Walmart.com ($0.18/strip).
If you’d like the option to sync your readings to an iPhone or iPod Touch, the Relion Prime syncs with the Glooko MeterSync Cable. The Glooko cable (with the free app on your iPhone/iPod Touch) allows you to sync all readings, as well as track factors that affect your glucose level, such as carbohydrate intake, activity level, and how you’re feeling. Though the cable costs $39.95 on Amazon, it’s a worthwhile investment if you plan on tracking your glucose levels over a long period of time.
I’m sure there are many other choices that work well, but this is the unit I have the most experience with, and in general, it is very reliable. Another good choice is the TrueTrack meter drugstores sell under their own brand name (i.e. Walgreens, Sav-on, etc.). Other models to consider are the One Touch Ultra or one of the Accu-Chek meters. The problem with these, however, is that the test strips tend to be more expensive than the Relion Prime.
Step two: test your blood sugar
- Test your blood sugar first thing in the morning after fasting for at least 12 hours. Drink a little bit of water just after rising, but don’t eat anything or exercise before the test. This is your fasting blood sugar level.
- Test your blood sugar again just before lunch.
- Eat your typical lunch. Do not eat anything for the next three hours. Test your blood sugar one hour after lunch.
- Test your blood sugar two hours after lunch.
- Test your blood sugar three hours after lunch.
Record the results, along with what you ate for lunch. Do this for two days. This will tell you how the foods you normally eat affect your blood sugar levels.
On the third day, you’re going to do it a little differently. On step 3, instead of eating your typical lunch, you’re going to eat 60 – 70 grams of fast-acting carbohydrate. A large (8 oz) boiled potato or a cup of cooked white rice will do. For the purposes of this test only, avoid eating any fat with your rice or potato because it will slow down the absorption of glucose.
Then follow steps 4-6 as described above, and record your results.
Step three: interpret your results
If you recall from the last article, healthy targets for blood sugar according to the scientific literature are as follows:
|Fasting blood glucose (mg/dL)
|OGGT / post-meal (mg/dL after 1 hour)
|OGGT / post-meal (mg/dL after 2 hours)
|OGGT / post-meal (mg/dL after 3 hours)
|Back to baseline
|Hemoglobin A1c (%)
*To convert these numbers to mmol/L, use this online calculator.
Hemoglobin A1c doesn’t apply here because you can’t test it using a glucometer. We’re concerned with the fasting blood sugar reading, and more importantly, the 1- and 2-hour post-meal readings.
The goal is to make sure your blood sugar doesn’t consistently rise higher than 140 mg/dL an hour after a meal but does consistently drop below 120 mg/dL two hours after a meal and returns to baseline (i.e. what it was before you ate) by three hours after a meal.
There are a few caveats to this kind of testing. First, even reliable glucometers have about a 10% margin of error. You need to take that into account when you interpret your results. A reading of 100 mg/dL could be anything between 90 mg/dL and 110 mg/dL if you had it tested in a lab. This is okay because what we’re doing here is trying to identify patterns – not nit-pick over specific readings.
Second, if you normally eat low-carb (less than 75g/d), your post-meal readings on the third day following the simple carbohydrate (rice or potato) challenge will be abnormally high. I explained why this occurs in the last article, but in short when you are adapted to burning fat your tolerance for carbohydrates declines. That’s why your doctor would tell you to eat at least 150g/d of carbs for three days before an OGTT if you were having that test done in a lab.
If you’ve been eating low-carb for at least a couple of months before doing the carbohydrate challenge on day three of the test, you can subtract 10 mg/dL from your 1- and 2-hour readings. This will give you a rough estimate of what your results would be like had you eaten more carbohydrates in the days and weeks leading up to the test. It’s not precise, but it is probably accurate enough for this kind of testing.
Third, as I said above, an occasional spike above these targets in the context of other normal blood sugar markers is usually no cause for concern.
Step four: take action (if necessary)
So what if your numbers are higher than the guidelines above? Well, that means you have impaired glucose tolerance. The higher your numbers are, the further along you are on that spectrum. If you are going above 180 mg/dL after one hour, I’d recommend getting some help – especially if you’re already on a carb-restricted diet. It’s possible to bring numbers that high down with dietary changes alone, but other possible causes of such high blood sugar (beta cell destruction, autoimmunity, etc.) should be ruled out.
If your numbers are only moderately elevated, it’s time to make some dietary changes. In particular, eating fewer carbs and more fat. Most people get enough protein and don’t need to adjust that.
And the beauty of glucometer testing is that you don’t need to rely on someone else’s idea of how much (or what type of) carbohydrate you can eat. The glucometer will tell you. If you eat a bowl of strawberries and it spikes your blood sugar to 160 mg/dL an hour later, sorry to say, no strawberries for you. (Though you should try eating them with full-fat cream before you give up!) Likewise, if you’ve been told you can’t eat sweet potatoes because they have too much carbohydrate, but you eat one with butter and your blood sugar stays below 140 mg/dL after an hour, they’re probably safe for you. Of course, if you’re trying to lose weight, you may need to avoid them anyways.
You can continue to periodically test your blood sugar this way to see how you’re progressing. You’ll probably notice that many other factors – like stress, lack of sleep, and certain medications – affect your blood sugar. In any case, the glucometer is one of your most powerful tools for preventing degenerative disease and promoting optimal function